Worksheet 10
Sources of Heat: sun, volcano, friction, burning fuels
Uses of heat: cooking, drying, heating, ironing
Applicances: hair dryer, iron, toaster, kettle
Things which change their state when heated- water, rubber, wax, butter
Uses of heat: cooking, drying, heating, ironing
Applicances: hair dryer, iron, toaster, kettle
Things which change their state when heated- water, rubber, wax, butter
Worksheet 11
1. Their spoons gained heat from the hot water and became too hot for the children to hold.
2. Copper ( Do not accept copper spoon as spoon is an object and not a material.)
3. Their spoons are made of materials which are poor conductors of heat and heat gain is slow, so the heat in the water could not reach their fingers.
4. Clay, ceramics, porcelain
1. Their spoons gained heat from the hot water and became too hot for the children to hold.
2. Copper ( Do not accept copper spoon as spoon is an object and not a material.)
3. Their spoons are made of materials which are poor conductors of heat and heat gain is slow, so the heat in the water could not reach their fingers.
4. Clay, ceramics, porcelain
Worksheet 12
1. The water has lost some heat to the surrounding air.
2. The jar wrapped in tissue paper. It is thin and allows heat to pass through easily.
3. The styrofoam
4. He should make a box made of styrofoam OR styrofoam box.
1. The water has lost some heat to the surrounding air.
2. The jar wrapped in tissue paper. It is thin and allows heat to pass through easily.
3. The styrofoam
4. He should make a box made of styrofoam OR styrofoam box.
Worksheet 13
1. The base is made of metal as metal is a good conductor of heat. When the saucepan is placed over a fire, it gains heat from fire and the food can be cooked quickly.
2. Plastic is a poor conductor of heat and heat gain is slow thus the plastic handle protects the person from burning his or her hands when they pick the saucepan.
3a) I will put on a pair of oven clothes. OR I will place a cloth over the metal handles before I carry it.
3b) The oven gloves and the thick cloth have pockets of air trapped inside them and air is a poor conductor of heat so they prevent the heat from reaching my hands quickly.
4. Electric iron OR kettle
Worksheet 14
1. SUN
2. LOSS
3. INSULATOR (Pls do not use in exam)
4. FRICTION
5 CELSIUS
6. HEAT
7. EXPAND
8. TEMPERATURE
9. MERCURY
10. THERMOMETER
1. SUN
2. LOSS
3. INSULATOR (Pls do not use in exam)
4. FRICTION
5 CELSIUS
6. HEAT
7. EXPAND
8. TEMPERATURE
9. MERCURY
10. THERMOMETER
Worksheet 15
1. No. The amount of water in Beakers A and B are not the same.
2. No. Th number of sugar cubes and the amount of water used are not the same in Beakers B and C.
3. She should use Beakers A and D. Only the temperature of water differs while the other factors remain the same.
4. The sugar cube in Beaker D dissolves faster than the one in Beaker A. As the temperature is higher in Beaker D, this means there is more heat present than in Beaker A (given the same volume of water in both beakers), so the sugar cube in D dissolves faster.
Worksheet 16
1. The leaf in Glass A was softer and more limp than the one in Glass B.
2. Although the water in both glasses was at 70 degree celsius, there was more heat energy in Glass A than in Glass B. This is because there is a larger amount of water in Glass A. Thus there was innsufficient heat in Glass B to completely cook the lettuce leaf but there was sufficient heat in Glass A to do so.
3. It indicates that the egg is partially cooked.
4. It indicates that the egg has not been cooked.
5. Even though the water that the eggs were cooked in was of the same temperature and quantity, Egg X was cold and would therefore have needed a longer time and more heat to cook sa compared to Egg Y.
Worksheet 17
1. Jagit heated the metal ball with a Bunsen Burner or dipped it into boiling water.
2. The metal ball expanded when it gained heat from the Bunsen burner (or waterm depending on your answer in 1.), making it too big to fit through the metal ring.
3.The metal ball lost heat to the iced water and contracted, allowing it to pass through the metal ring again.
Worksheet 18
(1) 2
(2) 4
(3) 4
(1) 2
(2) 4
(3) 4
Worksheet 19
(1) 3
(2) 4
(3) 1
(4) 2
(1) 3
(2) 4
(3) 1
(4) 2
Worksheet 20
1. Nathan could pour hot water over it or put the ball in a basin of hot water.
There should be no cracks because if there were cracks, he air would escape from the holes and not push out the dent when it expands on gaining heat from the hot water.
2. She was trying to make the bottle cap expand. Yes. As the cap gains heat from the hot water, it will expand, and thus she can open the bottle.
3. The spoon is made of metal which is a good conductor of heat. When the spoon is dipped into the boiling spoon, it gains heat quickly from the hot soup. When Sonya touched the spoon, her hand gains heat from the spoon and she can feel the heat.
