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Year
9
Aut
umn
Term
Sc
ienc
e H
omew
ork
Book
let
Nam
e
Form
Teac
her
My
teac
her
is
going
to t
est
me
on a
ll of
my
homew
ork
on
this d
ay e
very
we
ek.
MO
ND
AY
TUES
DA
Y
WED
NES
DA
Y
THU
RSD
AY
FRID
AY
Sect
ion
Due
by
Com
plet
ed. P
aren
ts s
igna
-tu
re
Biolog
y
1. Ce
ll St
ruct
ure
and
Func
tion
2.
Rep
rodu
ctiv
e s
yste
m a
nd v
aria
tion
3.
Inh
erit
ed D
isor
ders
4.
Com
pare
Inh
erit
ed D
isor
ders
Ch
emistr
y
1.
Rate
s : M
agne
sium
and
Hyd
roch
lori
c A
cid
2. R
ates
: M
agne
sium
and
Hyd
roch
lori
c A
cid
3. R
ates
:Sod
ium
Thi
osul
lpha
te a
nd
Hyd
roch
lori
c A
cid
Phys
ics
1.
Spee
d an
d A
ccel
arat
ion
2. D
ista
nce
/Tim
e Gr
aph
3.M
omen
tum
4.
Mom
entu
m a
nd L
ever
s
Inh
erit
ance
, Var
iati
on
an
d E
volu
tio
n:
Ho
mew
ork
1
Lea
rn t
he
spel
ling
s o
f th
e fo
llow
ing
key
wo
rds
and
th
eir
mea
nin
gs:
Nu
cleu
s: C
on
tro
ls t
he
cells
act
ivit
ies.
Co
nta
ins
DN
A w
hic
h is
org
anis
ed i
nto
ch
rom
oso
me
s.
Ch
rom
oso
me:
Th
read
like
str
uct
ure
s in
th
e ce
ll n
ucl
eus
that
co
nta
in D
NA
.
DN
A:
Fo
un
d a
s ch
rom
oso
mes
in
th
e n
ucl
eus.
Its
seq
uen
ce d
ete
rmin
es h
ow
ou
r b
od
ies
are
mad
e, a
nd
giv
es e
ach
on
e o
f u
s a
un
iqu
e ge
netic
cod
e.
DN
A is
a p
olym
er m
ade
up o
f tw
o st
rand
s fo
rmin
g a
doub
le h
elix
.
Gen
e: A
sm
all s
ecti
on
of
DN
A o
n a
ch
rom
oso
me.
Eac
h g
ene
co
des
fo
r a
par
ticu
lar
seq
uen
ce
of
amin
o a
cid
s, t
o m
ake
a sp
ecif
ic
pro
tein
.
Gen
om
e: t
he
enti
re g
enet
ic m
ater
ial
of
that
org
anis
m.
Th
e w
ho
le h
um
an h
as n
ow
bee
n s
tud
ied
an
d t
his
will
hav
e g
reat
imp
ort
ance
fo
r m
edic
ine
in th
e fu
ture
.
Lab
el t
he
dia
gra
m b
elo
w:
Cel
l Str
uct
ure
an
d F
un
ctio
n
H
om
ewo
rk 1
Questions
1. List the structures found in both animal and plant cells. 2. List the structures found only in plant cells. 3. What is the function of the nucleus? 4. What is the chemical called that makes up our chromosomes? 5. Describe the shape of the DNA molecule. 6. What does the sequence of DNA determine? 7. How many chromosomes does a normal body cell have? 8. How many chromosomes do sex cells have? 9. How are sperm cells adapted to their function?
Inheritance, Variation and Evolution: Homework 2
Label the reproductive systems using the words below:
Ovary Penis Uterus Urethra testis Vagina Sperm Duct
Cervix Oviduct Glands Foreskin Scrotum
Rep
rod
uct
ive
Sys
tem
an
d V
aria
tio
n
Ho
mew
ork
2
Complete the exam question below: (a) The diagram below shows the female reproductive system and a ciliated cell.
not to scale
Ciliated cells move an ovum along part of the reproductive system.
(i) In which part of the reproductive system are ciliated cells found?
............................................................. 1 mark
(ii) Into which part of the woman’s reproductive system does an embryo implant?
............................................................. 1 mark
(b) (i) Explain why a child can look like both parents but is not identical to ei-ther of the parents.
.....................................................................................................
.....................................................................................................
.....................................................................................................
.....................................................................................................
.....................................................................................................
..................................................................................................... 2 marks
(ii) In the table below, tick one box by each human characteristic to show whether it is:
• inherited only
• inherited and affected by environmental conditions.
human characteristic
inherited only
inherited and affect-ed by environmental
conditions
eye colour
skin colour
weight
1 mark maximum 5 marks
Inheritance, Variation and Evolution: Homework 3
Research an inherited disorder that you have NOT learnt about in class…
Can it be treated?
Name of disorder: _______________________________________________
How it is caused?
_____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________
What are the symptoms?
_____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________
Can it be passed on to children?
_____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________
Can it be treated?
_____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________
Inh
erit
ed D
iso
rder
s
H
om
ewo
rk 3
Inheritance, Variation and Evolution: Homework 4 Complete the exam question below… Embryos can be screened for genetic disorders. Many people would favour the use of embryo screening for cystic fibrosis but not for polydactyly. Compare the issues involved in the use of embryo screening for cystic fibrosis and for polydactyly. You should use your knowledge and understanding of the process and the two conditions. You could include: A brief description of the health effects of cystic fibrosis Arguments for screening for cystic fibrosis Arguments against screening for cystic fibrosis A description of brief description of the health effects of polydactyly Arguments for screening for polydactyly Arguments against screening for polydactyly
[6 Marks]
________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________
Co
mp
are
Inh
erit
ed D
iso
rder
s
H
om
ewo
rk 4
D
iffer
ence
s be
twee
n liv
ing
thin
gs o
f the
sam
e sp
ecie
s is
ca
lled
vari
atio
n.
Som
e va
riatio
n w
ithin
a s
peci
es is
inhe
rite
d (g
enet
ic
in
form
atio
n fr
om p
aren
ts),
and
som
e va
riatio
n is
due
to
the
envi
ron
men
t (ca
used
by
the
surr
ound
ings
).
S
ome
feat
ures
var
y be
caus
e of
a m
ixtu
re o
f inh
erite
d ca
uses
and
env
ironm
enta
l cau
ses.
Wei
ght a
nd h
eigh
t are
co
mm
on e
xam
ples
.
N
atur
al s
elec
tion
is a
pro
cess
by
whi
ch a
sp
ecie
s ch
ang
es o
ver
time
in r
espo
nse
to c
hang
es in
th
e en
viro
nm
ent,
or
com
pet
itio
n b
etw
een
orga
nism
s, in
or
der
for
the
spec
ies
to s
urv
ive
.
The
mem
bers
of t
he s
peci
es w
ith th
e m
ost d
esira
ble
ch
arac
teris
tics
are
able
to p
rodu
ce th
e b
est-
adap
ted
offs
prin
g. If
a s
peci
es is
una
ble
to a
dapt
then
it is
at
ris
k of
bec
omin
g ex
tin
ct.
N
atur
al s
elec
tion
lead
s to
evo
lutio
n w
hich
is a
slo
w
pr
oces
s th
at c
an ta
ke m
any
thou
sand
s, e
ven
mill
ions
, of
year
s to
hap
pen.
Inh
erit
ed
En
viro
nm
enta
l
Eye
col
our
Lang
uage
Lobe
d or
lobe
less
ear
s R
elig
ion
Abi
lity
to to
ll yo
ur to
ngue
F
low
er c
olou
r in
hyd
ran-
geas
(de
pend
s on
aci
dity
of
soi
l)
Sel
ecti
ve b
reed
ing
is t
he
trad
itio
nal
met
ho
d f
or
impr
ovin
g cr
ops
and
lives
tock
, suc
h as
incr
easi
ng d
isea
se
resi
stan
ce o
r m
ilk y
ield
. S
elec
tive
bree
ding
take
s pl
ace
over
man
y ge
nera
tions
. T
hese
are
the
mai
n st
eps
invo
lved
: 1.
de
cide
whi
ch c
hara
cter
istic
s ar
e im
port
ant e
noug
h to
se
lect
2.
ch
oose
par
ents
that
sho
w th
ese
char
acte
ristic
s 3.
ch
oose
the
best
offs
prin
g fr
om p
aren
ts to
pro
duce
the
next
gen
erat
ion
4.
repe
at th
e pr
oces
s co
ntin
uous
ly
D
NA
is v
ery
long
so
coile
d in
to s
truc
ture
s ca
lled
chro
mos
omes
.
Hum
an b
ody
cells
eac
h co
ntai
n 23
pai
rs o
f
chro
mos
omes
, hal
f of w
hich
are
from
eac
h pa
rent
.
The
chr
omos
omes
are
foun
d in
the
nucl
eus
of e
ach
cell.
A g
ene
is a
sec
tion
of D
NA
/chr
omos
ome
that
is
re
spon
sibl
e fo
r a
char
acte
ristic
like
eye
col
our
or b
lood
gr
oup.
Inh
erit
ance
, Var
iati
on
an
d E
volu
tio
n:
Kn
ow
led
ge
Org
anis
er
G
enet
ic d
iagr
ams
show
all
of th
e po
ssib
le a
llele
s fo
r a
pa
rtic
ular
cha
ract
eris
tic.
Dom
inan
t alle
les
are
capi
tal l
ette
rs,
whi
le t
he r
eces
sive
alle
les
are
low
er-c
ase
lette
rs.
T
his
gene
tic c
ross
sho
ws
thre
e-qu
arte
rs (
75%
) of
the
offs
prin
g ha
ve r
ed fl
ower
s (F
F a
nd F
f) a
nd a
qua
rter
(25
%)
have
whi
te
flow
ers
(ff)
.
C
ysti
c fi
bro
sis
is a
n in
herit
ed d
isor
der
of c
ell m
embr
anes
that
m
ainl
y af
fect
s th
e lu
ngs
and
dig
estiv
e sy
stem
. The
y ca
n
be
com
e cl
ogge
d w
ith lo
ts o
f thi
ck, s
ticky
muc
us a
s to
o m
uch
is
prod
uced
.
It
is c
ause
d by
a fa
ulty
rec
essi
ve a
llele
on
chro
mos
ome
7. T
o be
bor
n w
ith c
ystic
fib
rosi
s, a
chi
ld h
as t
o in
herit
two
copi
es o
f th
is fa
ulty
gen
e -
one
from
eac
h of
thei
r pa
rent
s.
Rate of Reaction 1: Magnesium was reacted with an excess of hydrochloric acid at room temperature.
The data in the table below was collected. Plot the data on a piece of graph paper.
Plot volume on the vertical y-axis and time across the x-axis
Make sure you label your graph correctly and use the correct units.
Put a best fit curve through your results.
1. Why was excess magnesium used?
2. How can you tell from the shape of your graph that the reaction is fastest at the beginning?
3. Explain why the reaction will gradually slow down.
Use the words particles and collisions in your answer.
4. How long did the reaction take to complete?
5. Calculate the average rate of reaction in cm3/s
6. Sketch on the same graph paper the curve you would expect if:-
a) powdered magnesium was used instead of strips (label the curve ‘area’)
b) the reaction took place at a lower temperature (label the curve ‘temp’)
Time (s) 0 10 20 30 40 50 60 70 80 90
Volume 0 50 78 98 110 116 118 120 120 120
Rat
es:
Mag
nes
ium
an
d H
ydro
chlo
ric
Aci
d
Ho
mew
ork
1
Rate of Reaction 2: A student investigated the rate of the reaction between magnesium and dilute hydrochloric acid. The student used the apparatus shown below to collect the gas produced.
Outline a plan to investigate how the rate of this reaction changed when the concentration of the hydrochloric acid was changed.
Describe how you would do the investigation and the measurements you would make. Describe how you would make it a fair test (which variables you would keep the same).
___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________
(6)
Rat
es:
Mag
nes
ium
an
d H
ydro
chlo
ric
Aci
d
Ho
mew
ork
2
Rate of Reaction 3: A student investigated the effect of temperature on the rate of a reaction. The picture below shows an experiment.
The student:
• put sodium thiosulfate solution into a conical flask • heated the sodium thiosulfate solution to the required temperature • put the flask on a cross drawn on a piece of paper • added dilute hydrochloric acid and started a stopclock • stopped the stopclock when the cross could no longer be seen • repeated the experiment at different temperatures. The equation for the reaction is:
(a) Explain why the solution goes cloudy. ___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
(2)
Rat
es:
So
diu
m T
hio
sulp
hat
e an
d H
ydro
chlo
ric
Aci
d
H
om
ewo
rk 3
(b) Give two variables the student must control to make the investigation a fair test. 1. _________________________________________________________________ 2. _________________________________________________________________
(2)
(c) State the effect that increasing the temperature of the sodium thiosulfate solution has on the rate of the reaction.
Explain this effect in terms of particles and collisions.
___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________
(4)
(d) Suggest how the student should change the method to investigate the rate of
reaction at 5°C. ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________
(1) (Total 9 marks)
Rate of Reaction 4: Lithium chloride, LiCl, sodium chloride, NaCl, and potassium chloride, KCl, are all soluble in water. The diagrams below show the energy change when each compound dissolves in water.
A student does an experiment. He dissolves each compound in water and measures the temperature change with a thermometer as the compound dissolves. He uses the same mass of each compound and the same volume of water each time. Use the energy level diagrams to help you explain the results that the student should expect from his investigation. You should use the words exothermic and endothermic in your answer. ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________
(6)
Rat
es:
En
do
ther
mic
an
d E
xoth
erm
ic R
eact
ion
s
H
om
ewo
rk 4
MA
KE
SUR
E YO
U C
AN
:
Des
crib
e pr
actic
ally
how
to m
easu
re ra
te (s
ee p
ract
ical
sh
eet o
n ‘m
easu
ring
rate
’)
Cal
cula
te ra
te o
f rea
ctio
n fro
m s
uppl
ied
data
or g
raph
s
Expl
ain,
in te
rms
of p
artic
les
and
collis
ions
, how
conc
entra
tion,
tem
pera
ture
, pre
ssur
e, s
urfa
ce a
rea
and
a ca
taly
st a
ffect
rate
of r
eact
ion,
and
why
reac
tions
slo
w
dow
n (a
s pa
rticl
es g
et u
sed
up, s
o le
ss c
ollis
ions
occ
ur)
Exte
nsio
n dr
aw ta
ngen
ts a
nd c
alcu
late
rate
from
the
gr
adie
nt o
f the
line
/cur
ve o
n a
grap
h
RAT
E O
F R
EAC
TIO
N
For a
reac
tion
to ta
ke p
lace
, par
ticle
s m
ust c
ollid
e, a
nd th
ey m
ust
collid
e w
ith th
e re
quire
d A
CTI
VATI
ON
EN
ERG
Y. T
his
is th
e m
inim
um e
nerg
y ne
eded
for a
re
actio
n to
take
pla
ce.
Fact
ors
Affe
ctin
g R
ate
(alw
ays
expl
ain
usin
g co
llisio
n th
eory
)
1. C
once
ntra
tion
- m
ore
conc
entra
ted,
mor
e pa
rticl
es,
mor
e fre
quen
t col
lisio
ns
2. P
ress
ure
- mor
e pr
essu
re
(gas
es),
parti
cles
clo
ser
to
geth
er, m
ore
frequ
ent
co
llisio
ns
3. T
empe
ratu
re -
hig
her
tem
p, p
artic
les
have
mor
e en
ergy
, par
ticle
s m
ove
fast
er,
mor
e co
llisio
ns (a
nd h
arde
r on
es -
mor
e lik
ely
to h
ave
activ
atio
n en
ergy
)
4. S
urfa
ce A
rea
- sm
alle
r pie
ces,
m
ore
surfa
ce a
rea,
mor
e ex
pose
d pa
rticl
es, m
ore
frequ
ent c
ollis
ions
5. C
atal
yst -
low
ers
activ
atio
n en
ergy
, E a
, mor
e fre
quen
t col
lisio
ns th
at n
ow
have
act
ivat
ion
ener
gy, E
a
TYPI
CA
L EX
AM
QU
ESTI
ON
Rea
ctio
n ta
kes
plac
e as
sh
own
here
and
is ti
med
un
til th
e cr
oss
bene
ath
the
coni
cal f
lask
can
no
long
er b
e se
en.
The
stud
ent i
s in
vest
igat
ing
the
effe
ct o
f tem
pera
ture
on
rate
. Giv
e tw
o va
riabl
es th
e st
uden
t mus
t con
trol t
o m
ake
the
inve
stig
atio
n a
fair
test
. Any
2 fr
om: v
ol o
f thi
osul
fate
, vo
l aci
d, c
once
ntra
tion
of th
iosu
lfate
, con
c of
aci
d
Stat
e th
e ef
fect
that
incr
easi
ng th
e te
mpe
ratu
re o
f the
so
dium
thio
sulfa
te s
olut
ion
has
on th
e ra
te o
f the
re
actio
n. E
xpla
in th
is e
ffect
in te
rms
of p
artic
les
and
co
llisio
ns. R
ate
incr
ease
s, p
artic
les
have
mor
e en
ergy
, m
ove
fast
er, m
ore
frequ
ent s
ucce
ssfu
l col
lisio
ns (w
ith E
a) Th
e re
actio
n at
20
°C p
rodu
ced
0.32
g o
f sul
fur i
n 64
se
cond
s. C
alcu
late
the
rate
of t
he re
actio
n, s
tatin
g th
e co
rrect
uni
ts. 0
.32
g / 6
4 s
= 0.
005
g/s
Exte
nsio
n C
an y
ou c
alcu
late
the
gra-
dien
t of a
tang
ent t
o th
e cu
rve
on
thes
e gr
aphs
as
a m
easu
re o
f rat
e of
re
actio
n at
a s
peci
fic ti
me
Gra
dien
t her
e w
ould
be:
10.4
g ÷
120
s =
0.0
87 g
/s
(2 m
ins)
INTE
RPR
ETIN
G G
RA
PHS
Mea
n (a
vera
ge) r
ate
of a
reac
tion
can
be c
alcu
late
d fro
m
supp
lied
data
or f
rom
gra
phs-
the
stee
per t
he g
radi
ent o
n th
e gr
aph,
the
fast
er th
e ra
te o
f rea
ctio
n
eg. i
f a re
actio
n m
akes
40
cm3 g
as in
60
seco
nds
mea
n ra
te =
40
cm3 ÷
60
s =
0.67
cm
3 /s
From
the
grap
hs s
how
n he
re, r
eact
ion
A is
fast
er a
s th
e cu
rve
(and
its
grad
ient
) is
stee
per.
Ther
e is
a g
reat
er in
crea
se in
the
amou
nt o
f pro
duct
ove
r a s
horte
r per
iod
of ti
me.
MEA
SUR
ING
RA
TE
The
rate
of a
che
mic
al re
actio
n ca
n be
foun
d by
mea
surin
g th
e qu
antit
y of
a re
acta
nt u
sed
or th
e qu
antit
y of
pro
duct
form
ed o
ver
time:
The
quan
tity
of re
acta
nt o
r pro
duct
can
be
mea
sure
d by
the
mas
s in
gra
ms
or b
y a
volu
me
in c
m3 .
Uni
ts o
f rat
e of
reac
tion
may
be
give
n as
g/s
or c
m3 /s
.
Met
hod
1 eg
. Mag
nesi
um re
actin
g w
ith h
ydro
chlo
ric a
cid
to
mak
e m
agne
sium
chl
orid
e an
d hy
drog
en, H
2
M
g +
2
HC
l —
> M
gCl 2
+
H2
The
gas
syrin
ge m
easu
res
the
volu
me
of g
as p
rodu
ced
accu
rate
ly. A
sto
pwat
ch w
ould
als
o be
nee
ded
to ti
me
the
reac
tion.
The
vol
ume
of g
as is
reco
rded
at r
egul
ar ti
med
in
terv
als,
eg.
eve
ry 1
0 se
cond
s.
Ther
e ar
e tw
o m
ain
way
s to
inve
stig
ate
the
rate
of r
eact
ion.
1) M
easu
re h
ow q
uick
ly a
gas
is b
eing
pro
duce
d
2) H
ow q
uick
ly a
reac
tion
gets
to a
fixe
d po
int (
colo
ur c
hang
e)
In e
ach
case
it is
impo
rtant
to id
entif
y th
e in
depe
nden
t, de
pend
ent
and
cont
rol v
aria
bles
.
To in
vest
igat
e th
e ef
fect
of c
once
ntra
tion
of a
cid
in m
etho
d 1
In
depe
nden
t var
iabl
e is
con
cent
ratio
n of
aci
d
D
epen
dent
var
iabl
e is
vol
ume
of g
as
C
ontro
l var
iabl
es w
ould
be
volu
me
of a
cid,
mas
s of
m
agne
sium
, sur
face
are
a of
mag
nesi
um, t
empe
ratu
re
The
resu
lts m
ight
be
used
to p
lot a
gra
ph:
The
stee
per t
he g
raph
, the
fast
er th
e re
actio
n is
goi
ng. I
t gra
dual
ly
slow
s do
wn
as p
artic
les
get u
sed
up. T
his
mea
ns le
ss s
ucce
ssfu
l co
llisio
ns a
re h
appe
ning
. The
reac
tion
stop
s w
hen
one
of th
e
reac
tant
s (th
e lim
iting
fact
or) g
ets
used
up
and
the
grap
h go
es fl
at.
If in
vest
igat
ing
the
effe
ct o
f tem
pera
ture
usi
ng m
etho
d 2,
cou
ld
you
list t
he in
depe
nden
t, de
pend
ent a
nd 3
or 4
con
trol v
aria
bles
?
Rat
es o
f Rea
ctio
n (P
RAC
TIC
AL)
Met
hod
2 eg
. a re
actio
n be
twee
n so
dium
thio
sulfa
te a
nd
hydr
ochl
oric
aci
d, th
at p
rodu
ces
a cl
oudy
pre
cipi
tate
of
sulp
hur (
S)
Na 2
S 2O
3 +
2
HC
l —
> 2
NaC
l +
S
+ S
O2
+ H
2O
Rea
ctio
n is
tim
ed fr
om w
hen
the
chem
ical
s ar
e m
ixed
, unt
il th
e po
int a
t whi
ch th
e cr
oss
is n
o lo
nger
vis
ible
bel
ow th
e co
nica
l fla
sk. T
he fa
ster
the
reac
tion,
the
less
tim
e it
take
s.
TYPI
CA
L EX
AM
QU
ESTI
ON
A st
uden
t inv
estig
ated
the
rate
of r
eact
ion
betw
een
mag
nesi
um a
nd h
ydro
chlo
ric a
cid
usin
g th
e ap
para
tus
belo
w
to c
olle
ct th
e ga
s pr
oduc
ed.
Out
line
a pl
an to
inve
stig
ate
how
the
rate
of r
eact
ion
chan
ged
whe
n th
e co
ncen
tratio
n of
the
hydr
ochl
oric
aci
d w
as
chan
ged.
D
escr
ibe
how
you
wou
ld d
o th
e in
vest
igat
ion
and
the
mea
sure
men
ts y
ou w
ould
mak
e
D
escr
ibe
how
you
wou
ld m
ake
it a
fair
test
You
do n
ot n
eed
to w
rite
abou
t saf
ety
prec
autio
ns
6 m
arks
MA
KE
SUR
E YO
U C
AN
:
Des
crib
e th
e m
etho
d ne
eded
to m
easu
re th
e ra
te fo
r a
pa
rticu
lar r
eact
ion
(if a
gas
is b
eing
mad
e us
e m
etho
d 1,
if a
co
lour
cha
nge
is h
appe
ning
use
met
hod
2), d
escr
ibin
g cl
early
w
hat y
ou w
ill ch
ange
(ind
epen
dent
), ho
w y
ou w
ill ch
ange
it,
wha
t you
will
mea
sure
(dep
ende
nt) a
nd w
hat y
ou w
ill ke
ep
the
sam
e to
mak
e it
a fa
ir te
st (c
ontr
ol v
aria
bles
)
Talk
abo
ut s
afet
y pr
ecau
tions
, eg.
dilu
te a
cids
can
be
irrita
nt
or c
orro
sive
(wea
r gog
gles
)
Nam
e th
e ap
para
tus
used
cor
rect
ly
Expl
ain
why
the
inde
pend
ent v
aria
ble
affe
cts
the
rate
, usi
ng
part
icle
s an
d co
llisi
ons
in y
our a
nsw
er
Exte
nsio
n - u
se g
radi
ents
on
grap
h to
det
erm
ine
rate
Y9 Forces 2 Homework 1 – Speed and Accelera on
Task 1
Complete these sentences using the words in the box. You may need to use some words
more than once.
Speed is a way of saying how something is moving. To work out a
speed.
we need to measure a and a .
The formula is: _________ = distance ÷ .
If the units for the distance are and the units for the ______________
are seconds, the units for speed will be .
The units for speed depend on the units for the distance and the me. Fill in the table.
distance fast metres metres/second speed me
Fo
rces
2 —
spee
d a
nd
Acc
eler
atio
n
H
om
ewo
rk 1
Units for distance
Units for me
Units for speed
miles
hours
mph
kilometres
kilometres per
hour
seconds
m/s
Task 2
(a) The ‘two second rule’ is a rule for car drivers. The rule is as follows:
‘Leave enough space between you and the vehicle in front so that you can pull up safely if it suddenly slows down or stops. . . A two second me gap may be sufficient. . . Use sta onary objects (eg lamp‐posts) to help you keep a two second gap.’
(The Highway Code, 1993)
(i) The traffic is moving at 20 m/s, and a driver is keeping to the ‘two second rule’. What is the distance between the driver and the car in front?
..................................................................................................
1 mark
(ii) The traffic increases its speed to 25 m/s, but the driver stays the same distance from the car in front. She sees the car in front pass a lamp post. How long will it take her to reach the same lamp post?
..................................................................................................
................................................................................................s
1 mark
(b) The driver decides to check her speedometer while driving along a motorway. She measures how long it takes her to travel 6 km. It takes her exactly 4 minutes. What was her speed in km/h? Show your working.
............................................................................................................
............................................................................................................
....................................................................................................km/h
2 marks
Maximum 4 marks
Dis
tan
ce /T
ime
Gra
ph
Ho
mew
ork
2
Y9 Forces 2 Homework 2 – Distance‐ me graphs
Complete the ques ons below about distance‐ me graphs
2. Work out which le er describes part of the journey. Write the correct le er to the correct part of the graph.
3. Calculate the speed for each different part of the line on the graph and write it next to each le er. You can use informa on from the descrip ons or from the graph.
Descriptions
1. The distance– me graph shows a journey by car.
a. Write an F on the graph next to the part of the journey with the fastest speed.
b. Write an S on the graph where the car stopped.
c. How long did the car stop for? ________
d. What was the total distance travelled?
The car travels 25 miles in the first 0.5 hours of the journey. Calculate its mean speed for this part of the journey.
Speed =
Light breeze in the morning, dropped to calm at midday. Only 50 miles covered in total.
Strong wind in the morning, covered 200 miles. Dropped to light breeze in a ernoon – total distance 250 for the day.
No wind un l midday, then a light breeze all a ernoon. 50 miles covered.
Calm – no wind at all.
Light breeze all day. 100 miles run. Fresh breeze all day. Speed about 8 mph all day.
Mo
men
tum
Ho
mew
ork
3 Y9 Forces 2 Homework 3 – Momentum
Answer the ques ons below about momentum
a) The diagram shows a car travelling at a speed of 12 m/s along a straight road.
(i) Calculate the momentum of the car.
Mass of the car = 900 kg
Show clearly how you work out your answer.
______________________________________________________________
______________________________________________________________
______________________________________________________________
______________________________________________________________
Momentum = _______________ kg m/s
(ii) Momentum has direc on.
Draw an arrow on the diagram to show the direc on of the car’s momentum.
(b) The car stops at a set of traffic lights.
How much momentum does the car have when it is stopped at the traffic lights?
___________________________________________________________________
Give a reason for your answer.
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
Y9 Forces 2 Homework 4 ‐ Moments and levers.
Complete the tasks below about moments and levers
Task 1
1. Draw lines to match up the words and their meanings.
2a Which lever should Viv use to li the car? Tick (ü) one box.
b Explain your answer to part a.
lever a force put on a lever
pivot a lever that can be used to take the tops from bo les
effort a lever that makes a force bigger
load a lever that makes something move further
force mul plier the point that the lever turns around
distance mul plier a long bar that can be used to increase the size of a force (or how far it moves)
bo le opener the weight or force on something
3. This seesaw will not balance.
Draw an arrow to show which way it will move.
Explain what the boys have to do to make the see‐saw balance.
Mo
men
tum
an
d L
ever
s
Ho
mew
ork
4
Task 2
Zena has a model plane attached to a rod as shown below. The plane is balanced by a sliding counterweight.
not to scale
(a) The rod is balanced horizontally.
(i) Calculate the moment produced by the counterweight.
Give the unit.
................................................................................................................
................................................................................................................
2 marks
(ii) What is the moment produced by the plane?
................................................................................................................
1 mark
(iii) Calculate the weight, W, of the plane.
................................................................................................................
..............................................................................................................N
1 mark
Forces 2 Summary sheet
Speed To measure how fast something is travelling, you need to measure the distance it travels and the time taken. Units for speed are km/h or m/s or mph. The unit for speed depends on the units you have used to measure the distance and the time.
Speed is calculated using this formula:
speed =
The mean (average) speed is the total distance travelled divided by the total time taken. Actual speeds during a journey can be faster or slower than the mean speed.
A car travelling at 50 km/h overtakes one travelling at 30 km/h. The relative speed of the faster car compared to the slower car is 20 km/h.
Distance–time graphs
Gradients
The gradient of a line on a graph is a measure of how steep the line is. On a distance-time graph, the gradient of a line gives the speed that the object is moving. Acceleration
An object that slows down is decelerating.
Near the Earth’s surface any object falling freely under gravity has an acceleration of about 9.8 m/s2.
A journey can be shown on a distance–time graph. This graph shows Kieron’s journey to school. The steeper the line on the graph, the faster the object or person is moving.
Example Calculate the speed of the object between 5 and 15 seconds.
gradient =
=
=
= 2.5 m/s
Velocity-time graphs The acceleration of an object can be calculated from the gradient of a velocity–time graph.
Momentum "Momentum is the property of a moving ob-ject that quantifies how difficult it is to be stopped".
Momentum is calculated using the equation: Momentum (kgm/s2) = mass (kg) x velocity (m/s2) Moments
moment (in N m) = force (in N) × perpendicular distance from the pivot (m).
The longer the distance the greater the moment. This is why it is easier to turn a long spanner than a short one. When an object is balanced, the anticlockwise moment is equal to the clockwise moment.
For the seesaw:
the anticlockwise moment = 300 N × 2 m = 600 N m the clockwise moment = 400 N × 1.5 m = 600 N m
The clockwise and anticlockwise moments are the same, so the seesaw is balanced, or in equilibrium.
A turning force is called a moment. Moments are measured in newton metres (N m).
Scholar’s Pathway
Levers
Simple machines
A lever is an example of a simple machine. Ramps and pulleys are simple machines that act as force mul pliers.
If a machine makes it possible to li or move a load using a smaller force, the force has to move through a greater distance. The total amount of energy needed is the same.
The work done by moving a load is the same as the energy transferred. Work is done when a force moves through a distance. Work is measured in joules (J).
work = force × distance moved in the direc on of the force.
The box stores the same amount of gravita onal poten al energy when it is in its final
posi on whichever method is used to li it. The law of conserva on of energy means that
only this amount of energy is used to li it.
Forces can be used to turn objects around piv-ots. A pivot is also known as a fulcrum.
Levers can be force multipliers, when they in-crease the force that is put in (the effort). They can be distance multipliers if they make the load move further than the effort. The amount the force or distance is multiplied depends on the distances between the load and the pivot, and the effort and the pivot.
The hammer is acting as a force multiplier.
The work done to lift the box 2 m is:
work = 1000 N × 2 m
= 2000 J
The ramp makes it possible to move the box using a force of only 500 N, but the box has to be moved 4 m.
work = 500 N × 4 m
= 2000 J.