WorksheetsThermal physics
Total questions: 19
Worksheet time: 11mins
The SI unit for measuring heat is the
Pascal
Kelvin
Joule
Calorie
When flying, some birds use warm air currents to gain height.
What is the cause of these currents?
conduction
convection
evaporation
radiation
Heat energy can be lost from a hot object by radiation.
What is the name of this radiation, and is it electromagnetic?
A
B
C
D
The diagram shows two narrow beakers A and B, and two wide beakers C and D. All four beakers contain the same mass of water.
Beaker A and beaker C contain low energy water molecules.
Beaker B and beaker D contain high energy water molecules. From which beaker does the water evaporate most slowly?
A
B
C
D
A swimmer feels cold after leaving warm water on a warm, windy day. Why does she feel cold even though the air is warm?
The less energetic water molecules on her skin escape quickly.
The more energetic water molecules on her skin do not escape quickly.
The water on her skin does not evaporate quickly enough to keep her warm.
The water on her skin evaporates quickly and cools her skin.
The diagram shows a beaker of water. Four molecules are labelled. The relative amount of energy of each molecule is shown. Which molecule is most likely to escape from the liquid?
A
B
C
D
Evaporation occurs when molecules escape from a liquid surface into the air above it. During this process the temperature of the liquid falls. Why does the temperature of the liquid fall?
The molecules in the vapour expand because the pressure is less.
The molecules left in the liquid have more space to move around.
The molecules move more slowly when they escape into the air.
The molecules with the highest energies escape into the air.
What is the name of the process of heat transfer using electromagnetic waves?
conduction
convection
evaporation
radiation
An experiment is set up to find out which metal is the best conductor of heat. Balls are stuck with wax to rods made from different metals, as shown in diagram 1. The rods are heated at one end. Some of the balls fall off, leaving some as shown in diagram 2. Which labelled metal is the best conductor of heat?
A
B
C
D
Two plastic cups are placed one inside the other. A small spacer keeps the two cups separated. Hot water is poured into the inner cup and a lid is put on top, as shown. Which statement is correct?
The bench is heated by convection from the bottom of the outer cup.
The lid reduces the energy lost by convection.
There is no thermal conduction through the sides of either cup.
Thermal radiation is prevented by the small air gap.
Which statement describes what happens as ice at 0°C starts to melt to become water?
Energy is absorbed and the temperature remains constant.
Energy is absorbed and the temperature rises.
Energy is released and the temperature remains constant.
Energy is released and the temperature rises.
The diagram shows electricity cables being put up on a warm day. The cables are left loose between the poles, as shown in the diagram. Why are the cables left loose?
They will contract on cold days.
They will contract on very warm days.
They will expand on cold days.
They will expand on very warm days.
