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Grade 4, Unit P.2, Heat and temperature 72 52
Physical science
Unit 4P.2: Heat and Temperature
Heat and temperature
Insulation
Science skills:
Estimating
measuring
Predicting
By the end of this unit you should know:
The difference between heat and temperature.
How to measure the temperature.
Things will either warm up or cool down to match
the temperature of their surrounding
Substances are different in their conducting and
insulating properties.
Grade 4, Unit P.2, Heat and temperature 73 52
Physical science
Make a mind map! Write as much as you know, even
draw, about the words HEAT and TEMPERATURE.
HEAT
TEMPERATURE
Grade 4, Unit P.2, Heat and temperature 74 52
Physical science
Activity: Heat and temperature
Is it hot or not?
Collect three bowls of water; fill the first one with
warm water, the second one with tap water. Fill the
last bowl with ice cold water.
Predict which bowl is the coldest. How do you know?
Test each bowl carefully with your hands. Were you
right? Put the bowls starting with the hottest.
We use our sense of touch to find out how hot our
surrounding is. You can feel the temperature of water
because the heat flows from the three bowls to your hand.
Now put one hand in the iced water, and the other
hand in the warm water, keep them there for a about
a minute. Take them out and put your both hands in
the third bowl. Discuss how you feel?
Heat is a flow of energy from warmer matter to cooler matter.
4.14.1, 4.14.2
Grade 4, Unit P.2, Heat and temperature 75 52
Physical science
We feel the heat with our hand but sometimes our senses
can be fooled!
Have you ever felt that you didn’t need a
jacket, and then when you went outside you
were wrong!
Sometimes we need to know the exact
temperature of things.
To measure the temperature accurately we use a
thermometer.
Many thermometers are made of glass tubes.
At the bottom of the tube is a wider part
called the bulb. The bulb is filled with a liquid.
Some liquids that can be used are mercury (
this is not allowed in schools as it is very
dangerous) or colored alcohol. When the bulb is
heated, the liquid in the bulb expands, or gets
larger. It rises in the glass tube. When the
bulb is cooled, the liquid contracts, or gets
smaller. It falls in the tube.
On the sides of the thermometer are a series of marks.
You read the temperature by looking at the mark on the
tube where the liquid stops.
This is a regular thermometer and
it is used in many ways
Grade 4, Unit P.2, Heat and temperature 76 52
Physical science
Temperature is usually measured on two scales. They are
the Fahrenheit scale and the Celsius scale.
Activity:
Predict the temperature of each bowl.
Check your predictions by using a
thermometer.
Record your results in the table.
How close were your estimates?
Bowl
Estimated
Temperature
What YOU
think!
Measured
temperature
Actual
temperature
Warm water
Tap water
Cold water
Measuring temperature
The temperature can be estimated using our sense of
touch. In order to measure the temperature accurately we
use the thermometer.
Temperature is a measure of how hot or cold something is.
Grade 4, Unit P.2, Heat and temperature 77 52
Physical science
Types of thermometers:
Clinical thermometers: The clinical thermometers are used
to measure the body temperature of the patient like:
Ear thermometer Underarm thermometer Oral thermometer
Food thermometers: There are many food thermometers
like:
Dial oven-safe thermometers digital instant thermometers
Outdoor thermometers: The
outdoor thermometers are used to
measure the temperature of the
surrounding air.
Grade 4, Unit P.2, Heat and temperature 78 52
Physical science
Flow of Heat
Don’t let it get cold
1. Imagine a hot dinner on a cold day. What happens to
it if you don’t eat it straight away?_____________
2. Imagine a cold drink on a hot day. What will happen
to it if you leave it for a long time before you drink
it?__________________
Does the temperature of something hot or cold change to
be more like the temperature of its surrounding?
Activity:
You will need:
3 thermometers
A bowl of iced water
A bowl of tap water
A bowl of warm water
Grade 4, Unit P.2, Heat and temperature 79 52
Physical science
Steps:
1. Firstly measure and record the temerature of the
room.
Room temperature ______________
2. Estimate and then measure the temperature of the
water in each of the three bowls. Record your
measurements.
3. What do you predict the temperature of the water in
the three bowls will be in one hour’s time? Explain your
prediction. ___________________________________
Bowl
Iced water Tap water Warm water
Estimated
temperature
Measured
temperature
Temperature
after 10 min.
Temperature
after 20 min.
Temperature
after 30 min.
4. Leave the bowls for 10 minutes. Measure the
temperatures again and after 20 minutes and 30 minutes.
Grade 4, Unit P.2, Heat and temperature 80 52
Physical science
What do you notice? Can you explain what happened?
______________________________________________
What do you notice about the temperature of the bowls
and the room?
______________________________________________
Anything that is at a different temperature from its
surrounding will change temperature over time. If left long
enough, it will either warm up or cool down to match the
temperature of all other things around it, including the air.
Both the hot dinner and the cold drink will end up at the
temperature of the surrounding air.
Grade 4, Unit P.2, Heat and temperature 81 52
Physical science
Activity
Time
Temp
Fix a thermometer
outside – decide with
your teacher where.
Measuring the
temperature during
the day and complete
the table:
Time Temperture outside
7am
9am
11am
1pm
2pm
Use the data and plot a graph. Join
the lines making a curve.
Questions:
When was the temperature
is highest during the day
(24 hours)? ____________
Why do you think it
was the highest at
that time?
_____________________
_____________________
_____________________
Grade 4, Unit P.2, Heat and temperature 82 52
Physical science
Key words:
Heat
Temperature
Thermometer
Degrees
Celsius
Fahrenheit
Surrounding
Room
temperature
Key ideas:
How hot or cold something is, is
called temperature.
We can measure the
temperature using a
thermometer.
Heat, a flow of energy from
warmer matter to cooler matter.
Over time, every material will
become the same temperature as
its surrounding.
Key questions:
1. What is the difference between heat and
temperature? --------------------------------------------------------------
--------------------------------------------------------------
--------------------------------------------------------------
2. Explain why energy flows from the outside air into the
inside of a refrigerator. -----------------------------------------------------------------------------
-----------------------------------------------------------------------------
--------------------------------------------------------------------------
Grade 4, Unit P.2, Heat and temperature 83 52
Physical science
3. Look at the following picture below. What will happen
to the temperature after (1) hour? The temperature of
the juice will be:
a) The same temperature
b) The room temperature
c) Increased over time
4. Look at the thermometer. Write the temperature it
shows in °C.
20°C
Grade 4, Unit P.2, Heat and temperature 84 52
Physical science
Insulation
All cups have hot liquid in it. Which cup would you prefer
to hold? And why? Discuss. Think carefully about this one!
Materials that allow heat to pass through them easily are
called thermal conductors.
Metals and glass are good thermal conductors.
Some materials do not conduct heat well. They are called
thermal insulators.
Materials such as plastics, wood, wool and air are good
thermal insulators.
4.14.3
Grade 4, Unit P.2, Heat and temperature 85 52
Physical science
Thermal insulator
A thermal insulator is a material that does not allow heat
to travel through it easily.
Which of these spoons do you think will be a good thermal
insulator?
Metal spoon Wooden spoon Plastic spoon
A saucepan of hot water
Think…
What does the handle of each spoon feel like when
they have been standing in the hot water for 10 minutes?
Grade 4, Unit P.2, Heat and temperature 86 52
Physical science
Activity
You will need
Three cups made from different materials (plastic-glass-
metal), thermometers, and hot water.
Steps:
1. Fill the cups with hot water.
2. Measure the temperature of the cups.
3. After 15 minutes measure the temperature again.
4. Record your results what do you observe
Cup
Plastic Glass Metal
Temperature
Temperature after
15 minutes
Which material would you choose for a cup of tea? Why?
_____________________________________________
Insulation Activity
You will need:
3 identical cups (with covers).
kettle (for boiling water – your teacher will pour the
hot water for you),
3 thermometers,
3 different types of materials (bubble wrap, foil,
paper, elastic bands).
Grade 4, Unit P.2, Heat and temperature 87 52
Physical science
What do you need to keep the same? In order to make it
a FAIR test
___________________________________
Wrap each cup with ONE of the materials, use elastic
bands to help you.Put the lid, on make sure you have a
hole to put the thermometer through. Record the temp
every minute for 13min.
Material Time (mins)
Foil
Paper
Bubble
Wrap
This is the same experiment as
yours. Here they are using
metal cups and digital
thermometers, you can see the
different insulation they are
using.
Grade 4, Unit P.2, Heat and temperature 88 52
Physical science
Think about it?
Five glasses containing water at 60˚C were each wrapped
in a different material. After 10 minutes, the water
temperature in each glass was recorded. The results are
shown in the table below.
Which material would you choose to wrap around a water
pipe in winter to stop the water from freezing? Explain
why? ______________________________________________________________
Some materials conduct heat very well.
Saucepans are made from
metals: they heat up
quickly. However the
handles are usually made
from another material
Such as plastic or wood,
because they are
insulators.
Think of a metal spoon
that has been left in a
steaming cup of coffee-it
gets very hot! Metals are
materials that conducts
heat well.
Grade 4, Unit P.2, Heat and temperature 89 52
Physical science
Project:
What’s the problem with getting ice-cream home
from the shops in the summer? Yes, it nearly
always starts melting before you can get to the
freezer.
Your challenge is to design some kind of packaging or bag
that will keep ice-cream cold for enough time to get home
from the shops. You will make your design in school.
What I will need:
_____________________ _____________________
_____________________ _____________________
_____________________ _____________________
What I will do:
_____________________________________________
_____________________________________________
_____________________________________________
Why I think it will work:
_____________________________________________
_____________________________________________
____________________________________________
Explain why some materials keep foods cool and
others don’t.
__________________________________________
__________________________________________
______
Grade 4, Unit P.2, Heat and temperature 90 52
Physical science
Key words:
Thermal
conductor
Thermal
insulator
Conduct
Insulate
Key ideas:
Materials that allow heat to
pass through them easily are
called thermal conductors.
Materials do not conduct heat
well are called thermal
insulators.
Key questions:
1. What do we call materials that do not let heat pass
through them?
--------------------------------------------
2. Salman bought a flask. Which of these are true and
which are false?
a. The flask will only keep drinks hot. True / False
b. The flask will keep cold drinks cold. True / False
c. The flask will not keep cold drinks cool.
True / False
d. The flask will keep hot drinks hot. True / False
Grade 4, Unit P.2, Heat and temperature 91 52
Physical science
3. Sara is cooking some rice at home. She puts water
into a metal pan and places the pan on the cooker.
Why is metal a good material for the pan?
_________________________________________________
4. Look at the graph and answer these questions.
a. Which cup kept the liquid warmest? .....................
d. Which cup is the best thermal insulator? ......................
c. What do you think was the temperature of the
room? .....................