2.3) Heat transmission

Question 1

Internal energy

Answer 1

Kinetic energy added to potential energy

Question 2

What is meant by increase in internal energy

Answer 2

Increase in kinetic energy or potential energy of molecules

Question 3

Conduction

Answer 3

Flow of heat through matter from places of higher temperature to places of lower temperature without movement of matter

Question 4

Explain how thermal energy is transferred through the aluminium

Answer 4

Atoms vibrate passing on energy of vibration to neighbouring atoms. Atoms pass on energy to free electrons. Electrons hit distant atoms.

Question 5

Explain how electrons transfer thermal energy through the metal of can

Answer 5

Ions vibrate, free moving electrons move and hit atoms

Question 5

How electrons transfer thermal energy through metal of this container

Answer 5

Metals contains free moving electrons They gain energy from the hot parts and move through the lattice. Free electrons collide with metal ions in other parts so thermal energy is transferred

Question 6

Convection

Answer 6

The flow of heat through a fluid from places of higher temperature to lower temperature by movement of fluid itself

Question 7

Explain convection in room heater

Answer 7

Warm air above the heater expands, becomes less dense, rises upwards, and cooler, more dense air sinks at the bottom to replace it. Creating a convection current