Section D Energy Rescources And Energy Transfer

Question 1

What is the equation to calculate the efficiency?

Answer 1

Efficiency = useful energy output / total energy input

Question 2

What is conduction of heat?

Answer 2

Mainly in solids, when the heat passes from the tight particles, making each other vibrate.

Question 3

What is convection of heat?

Answer 3

Only in gases and liquids; occurs when the more energetic particles move from the hotter region to the cooler region, and take their heat energy with them (a lot like diffusion only with heat).

Question 4

What are convection currents?

Answer 4

Changes in density.

Question 5

What is the formula for work done?

Answer 5

Work Done = Force x Distance Moved.

Question 6

How do you calculate the power in terms of ‘rate in doing work’?

Answer 6

Power = work done / time taken

Question 7

What is power measured in?

Answer 7

Watts or joules per second.

Question 8

What is the principle of the conservation of energy?

Answer 8

Energy cannot be created or destroyed; it can only be transferred as one type to another.