Physics Heat Transfer Lower Sec Worksheet - Free Printable

1. a. Which metal has the least volume during cooling? [1m]
b. Explain why. [1m]
c. What would you expect to observe when these 2 bimetallic strips are heated? [2m]

2. 5. Explain why metals are good conductors of heat. [2m]
Metals are good conductors of heat because they have free electrons that can move easily throughout the metal lattice. When heat is applied, these free electrons gain kinetic energy and transfer it rapidly through the metal by colliding with other electrons and atoms, allowing heat to be conducted efficiently.

3. 6. Using particulate model of matter, explain how heat is conducted in solids. [3m]
In solids, particles are closely packed in a fixed arrangement. When heat is applied, the particles at the heated end gain kinetic energy and vibrate more vigorously. These vibrating particles collide with neighboring particles, transferring energy to them. This process continues through the solid, allowing heat to be conducted from the hotter region to the cooler region.

4. 7. An experiment is carried out as shown in the diagram. Why does the ice take a long time to melt even though the water at the top of the tube is already boiling?
A) Ice is a poor conductor of heat.
B) Water is a poor conductor of heat
C) The metal gauze prevents the heat energy from reaching the ice by conducting the heat away.
D) Convection cannot take place in water. [2m]
The correct answer is B) Water is a poor conductor of heat.
Explanation: Water is a poor conductor of heat, so the heat from the boiling water at the top does not transfer efficiently to the ice at the bottom. Although convection currents may occur in the water, the heat transfer is slow, and the ice takes a long time to melt. The metal gauze is used to prevent the flame from directly touching the glass, but it does not significantly affect heat conduction to the ice. The primary reason is that water itself does not conduct heat well, so the heat from the top does not reach the ice quickly.