SECRET SUCCESS ENTHUSIASM - … · Diagram 2 shows a loaded lorry. Diagram 2 Explain the suitable loaded lorry which can carry liquid, such as petrol. Modification/ Characteristics

NOR AZLINA BINTI MOHD ARIF MRSM TUN GHAFAR BABA JASIN, MELAKA

8 JULAI 2017 MRSM MUAR

THE REAL SECRET

OF SUCCESS IS

ENTHUSIASM

A we s om e p h y s i c s i s a r o u n d y o u

LOVE PHYSICS – TGB + MUAR 2

SECTION B (MODIFICATION) EXAMPLE

1. Diagram 1 shows an ammeter to measure an electric current.

Diagram 1

Using suitable concepts of physics, suggest and explain the necessary adaption to be made so that the ammeter can give readings that are more sensitive, consistent and accurate. State two precautionary steps that must be taken when taking the reading through the ammeter.

Modification/ Characteristics Explanation

Small size of scale Can detect smallest change in current flow

Mirror strip To avoid parallax error

Zero adjuster To avoid zero error To adjust the pointer at the zero mark

Lighter needle (pointer) Easy to detect current Sensitive to the change of current flow

Precautionary steps: - make sure our eye perpendicular to the reading of ammeter to avoid parallax error - switch off the circuit the after taking the reading to avoid over heating

2. Diagram 2 shows a loaded lorry.

Diagram 2

Explain the suitable loaded lorry which can carry liquid, such as petrol.

Modification/ Characteristics Explanation

Use ABS/air brake

Lorry does not stop immediately Increase the time for lorry to stop Lorry does not skid More friction with ABS Prevent wheel lock // wheel does not lock Prevent lorry spinning on wet surface

Use Two tyres // Double tyres // Many tyres //More than one

Can support heavy load Less damage to the road Low pressure coz surface area is high

The load of lorry should be divide into many small tanks

Does not shake easily To increase stability

Far gap distance between tractor and trailer

To prevent collisions between the trailer & the tractor To reduce force // velocity

Small belt behind lorry To discharge spark Safety reason to prevent from burning the petrol

The load must be tied So it will not fall of from the lorry


UNDERSTANDING QUESTION (4 marks) EXAMPLE

1.

SBP 2007

By using the relevant physics concept, explain why a softball player moves his hand backwards while catching a fast moving ball.

Answer:

Fast moving ball, higher force toward hand.

Hand moves backwards, time impact increase.

Time increase, impulsive force decrease.

Ball catch firmly and prevent injury.

2.

SPM 2009

Diagram 1 shows a vacuum cleaner.

Diagram 1

Explain how the vacuum cleaner is able to remove dust from the floor.

Answer:

Fan blows air out from vent

Low pressure inside vacuum cleaner

High pressure outside vacuum cleaner

Different in pressure result sucking force

3.

SBP 2011

Diagram 2 shows a plasticine ball being dropped onto a metal block. The plasticine ball changes its shape after the impact.

Diagram 2

Answer:

The surface of metal block is hard.

The time impact is shorter

The impulsive force is bigger

Big force change the shape of plasticine


FULL FORMAT SECTION B

1. Diagram 1.1 shows the effect of a man falls from a high position to the ground without opening the parachute. Diagram 1.2 shows a man with the same mass falls from the same height when the parachute is open.

(a) (i) What is the meaning of the free fall? [1 mark]

(ii) Based on Diagram 1.1 and Diagram 1.2, compare the acceleration, the rate of change of

momentum and the time impact. Relate the rate of change of momentum with the time of impact to make a deduction on the relationship between the acceleration and the rate of change of momentum.

[5 marks]

(b) A hovercraft moves on a cushion of air which is trapped underneath it as shown in Diagram 1.3. The trapped air reduces the friction. The hovercraft starts from rest and as it starts, the propeller produces a forward force until it reaches a constant velocity.

Diagram 1.3


(i) Sketch a velocity-time graph to show the motion of hovercraft.

(ii) Explain why the hovercraft moves with constant velocity in terms of the force acting on it.

[4 marks]

(c) Diagram 1.4 shows a canoe.

Diagram 1.4 You are required to give some suggestions to design a canoe which can travel faster and safer. Using the knowledge on motions, forces and the properties of materials, explain the suggestion based on the following aspects:

(i) The surface of the canoe

(ii) The shape of the canoe

(iii) The size of a peddle

(iv) Material used for peddle

[10 marks]

TOTAL 20 marks


NO. ANSWER

1. (a) (i) State the meaning of free fall

(ii) Comparison

(b) (i)

(ii)

(c) Modification

Characteristics Reason

TOTAL 20 MARKS


SPM 2012

2. Diagram 2.1 shows the positions P and Q at different altitude. Two identical simple barometers are placed at both positions. The height of the mercury column in the barometers are shown in Diagram 2.2.

Diagram 2.1

Diagram 2.2

The density of air at P is 1.2 kg m-3 and the density of air at Q is 1.0 kg m-3.

(a) What is the meaning of density? [1 mark]

(b) Using Diagram 2.1 and Diagram 2.2, compare the altitudes of P and Q,

the density of surrounding air and the height of mercury column in the simple barometer at positions P and Q.

[3 marks]

(c) State the relationship between the altitude and (i) the density of the air (ii) the atmospheric pressure

[2 marks]


(d) Diagram 2.3 shows a dropper in a bottle.

Diagram 2.3

Using the knowledge of atmospheric pressure, explain how the liquid in the bottle can be sucked into the dropper tube.

[4 marks]

(e) Diagram 2.4 shows a vacuum cleaner.

Diagram 2.4

You are required to give some suggestions to design a vacuum cleaner which can clean the dust faster and effectively. Using the knowledge on atmospheric pressure, Bernoulli's principle and properties of materials, explain your suggestions based on the following aspects:

(i) Material used for the body of vacuum cleaner.

(ii) Material used for the hose.

(iii) The size of the fan.

(iv) The size of the floor nozzle.

(v) The diameter of wand. [10 marks]

TOTAL 20 marks


SECTION C (DECISION MAKING)

1. You are a coach responsible to choose a student to join the school basketball team. A basic physical fitness test was carried out and the results based on certain characteristics are as shown in Table 1.1

Characteristics Mass (m/kg)

Height (m)

Responding time (s)

Power (time taken to transfer

50 bricks to a distance 5

m) (minute)

Time taken to complete 100 m run

(s)

A 70 1.30 0.01 4 11.0

B 65 1.50 0.20 3 10.6

C 50 1.70 0.01 2 10.5

D 60 1.40 0.05 2 11.2

E 40 1.60 0.04 1 12.4

Table 1.1

(a) What is meant by power?

[1 mark]

(b) Based on table 11.1, explain the suitable characteristics of the student to be in the basketball team. Choose which student will be in the basketball team and explain your choice.

[10 marks]

(c) When a 100 m runner reached the finish line, the runner stopped suddenly and fell on the ground. Explain the situation using the appropriate physics concept.

[4 marks]

(d) Two students were asked to run up the stairs to the top floor of a 10 m building. Data obtained for the two students are as shown by Table 1.2.

Mass/kg Time/s

Student 1 55.0 12.0

Student 2 60.0 14.0

Table 1.2

Calculate power of each student and determine which student has the highest power.

[5 marks]

TOTAL 20 marks


NO. ANSWER

1. (a) State the meaning of power

(b) Decision making

Characteristics Reason

(c) Explain the situation using the appropriate physics concept.

(d) Calculation

TOTAL 20 MARKS


2. Diagram 2 shows two pairs of shoes used by a lady.

The shoes in Diagram 2.1 is used when she is going for work in office and the shoes in Diagram 2.2 is used when she went for jogging.

Diagram 2.1

Diagram 2.2

(a) What is meant by pressure? [1 mark]

(b) The shoes in Diagram 2.2 is more suitable to use for jogging along the beach compared to the

shoes in Diagram 2.1. Explain why?

[4 marks]

(c) Diagram 2.3 shows a pair of outdoor shoes suitable for mountain trekking.

Diagram 2.3


Table 2.4 shows the characteristics of five types of materials that can be used for making the soles of the trekking shoes.

Type of material

Density (kgm-3)

Number of studs

Expansion effect

Ability to stretch

P 820 6 Low Good

Q 700 8 Low Good

R 750 4 High Poor

S 880 3 High Poor

Table 2.4

You are asked to study the characteristics of the materials shown in Table 2.4. Explain the suitability of each characteristics in Table 2.4 and then determine the most suitable material to be used. Give a reason for your choice.

[10 marks]

(d) A man of mass 60 kg runs along a dirt track. The soles of his shoes is 20 cm2. He exerts a forward force of 100 N while the total frictional force from the dirt track against his running shoes is 20 N.

(i) What is the pressure exerted? [2 marks]

(ii) Find the acceleration of the man? [3 marks]

TOTAL 20 Marks


TRIAL MRSM 2014 3. Diagram 3.1 shows a load hanging from a rope.

Diagram 3.2 shows the similar rope breaking when another load is hung on it. Forces are exerted on the ropes when loads are hung on it.

Diagram 3.1 Diagram 3.2

(a) What is the meaning of force? [1 mark]

(b) (i) Explain why the rope does not break in Diagram 3.1 while the rope breaks in

Diagram 3.2. [2 marks]

(ii) State the energy change when the object in Diagram 3.2 falls to the ground and sketch

two graphs to represent the energy change against time. [3 marks]

(c) Diagram 3.3 shows a child playing on a swing. The mass of the child is 15 kg and the

angle of swing with the vertical is 15o.

Diagram 3.3


(i) Calculate the tension of the rope. [3 marks]

(ii) If another child of weight 250 N plays on the swing, will the rope break if its maximum

tension is 300 N? [1 mark]

(d) Diagram 3.4 shows the side view of a car.

Diagram 3.4 Table 3.5 shows four safety car seats K, L, M and N with different specifications. You are required to determine the most suitable car seat and the way it is positioned on the front passenger seat, for babies’ safe travel. Explain the suitability of each characteristic of the car seat and position. Determine the most suitable car seat and position. Give a reason for your choice.

K

Car seat fastened facing the front

L

Car seat fastened facing the rear


M

Car seat fastened facing the rear

N

Car seat fastened facing the front

Table 3.5

[10 marks]

TOTAL 20 Marks


-PHYSICS DICTIONARY- F4 - CHAPTER 2 – FORCE & MOTION

TERMS DEFINITION / MEANING FORMULA

Distance The total path length travelled from one location to the other

Displacement

The distance between two locations measured along the shortest path connecting them in a specified direction

Speed

Rate of change of distance OR Distance travelled per unit time

t

sv

Velocity

Rate of change of displacement

t

sv

Acceleration

Rate of change of velocity

t

uva

Deceleration

Rate of decrease in velocity

v ua

t

Inertia

The tendency of the object to remain at rest or if moving to continue its motion

Mass The quantity of matter in an object

Momentum Product of mass and velocity mvp

Principle of conservation of momentum

In a closed system, the total momentum before collision is equal to the total momentum after collision provided there is no external force

Elastic collision

A collision in which the objects do not combine after collision 1 1 2 2 1 1 2 2m u m u m v m v

Inelastic collision

A collision in which the objects are combined after collision 1 1 2 2 1 2m u m u m m v

Force An agent that can change the shape, velocity and displacement of an object

F ma

Unbalanced / net / resultant force

A single force that represents the combined effect of two or more forces with magnitude and direction

Balanced forces / Forces in equilibrium

Situation in which forces acting on an object produces no net force. The object is satationary or moves with a constant velocity in a straight line.

Impulsive force Rate of change of momentum t

)uv(mF

Impulse Change in momentum mumvimpulse

Impulse = Ft

Gravitational field

The region around the earth which an object experiences a force towards the centre of earth

Gravitational field strength

The gravitational force acting on a mass of 1 kg placed at that point

g = 10 N kg -1

Gravitational acceleration

The acceleration of an object due to the pull of the gravitational force

g = 10 m s -2

Free fall The motion in which the object falls due to gravitational force only


Weight

The gravitational force acting on the object mgW

Newton’s Second Law of Motion

The acceleration produced by a net force on an object is directly proportional to the magnitude of the net force applied and is inversely proportional to the mass of the object. t

)uv(mF

Resolution of forces

The separation of a single force into two perpendicular components called the vertical and the horizontal component

1 Newton

Is the force which acts on a body of mass 1 kg and causes the body to accelerate at 1 m s -2

Energy The ability to do work

Work done

The product of the applied force and the displacement in the direction of the applied force

W = Fs

Power

The rate at which work is done OR the amount of work done per second

W EP

t t

1 watt

The power generated when 1 J of work is done in 1 s

Kinetic energy The energy of an object due to its motion 21

2kE mv

Gravitational potential energy

The energy of an object due to its higher position in the gravitational field

pE mgh

Principle of Conservation of energy

Energy cannot be created or destroyed. Energy can be transformed from one form to another. The total energy in a closed system is constant .

Efficiency

The percentage of the energy input that is transformed into useful energy 100%out

in

EE x

E

Elasticity

The ability of an object to return to its original size / length / shape when the force that is acting on it is removed.

Hooke’s Law

The extension of a spring is directly proportional to the applied force provided the elastic limit is not exceeded

F kx

Elastic limit

The maximum force which can act on an object before it loses its elasticity

Force constant / spring constant

Force per unit extension

Fk

x

Elastic potential energy

The energy stored in an object when it is stretched or compressed

21 1

2 2pE Fx kx


F4 - CHAPTER 3 – FORCES & PRESSURE

TERMS DEFINITION / MEANING FORMULA

Density Mass per unit volume

Pressure

Magnitude of force acting perpendicularly to a surface per unit area of the surface OR Force per unit area

FP

A

P gh

1 Pascal or 1 N m -2

The pressure exerted on a surface when a force of 1 N acts perpendicularly to an area of 1 m 2

Atmospheric pressure

The pressure due to the weight of the air acting per unit area on the earth’s surface

Pascal’s Principle

The pressure applied to an enclosed fluid is transmitted uniformly to every part of the liquid.

1 2

1 2

1 1 2 2

F FP

A A

P A h A h

Buoyant force

The upward force exerted by a fluid when an object is wholly or partially immersed in the fluid

BF Vg

Archimedes’ Principle

For a body wholly or partially immersed in a fluid, the buoyant force is equal to the weight of the fluid it displaces

Bernoulli’s Principle

In a moving fluid, where the speed is low, the pressure is high and where the speed is high, the pressure is low

’

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Difficult roads often lead to beautiful destinations…. Good luck

…

Documents

SECRET SUCCESS ENTHUSIASM - … · Diagram 2 shows a loaded lorry. Diagram 2 Explain the suitable loaded lorry which can carry liquid, such as petrol. Modification/ Characteristics