A3 Work, Energy and Power

Question 1

State the principle of the conservation of energy.

Answer 1

Energy cannot be created or destroyed; it can only be transformed from one form to another.

Question 2

Define work done and calculate it using W = Fscosθ.

Answer 2

Work done is the energy transferred by a force acting over a distance (W = F × s × cos(θ)).

Question 3

Define power and solve problems involving power.

Answer 3

Power is the rate at which work is done or energy is transferred (P = W/t).

Question 4

Define efficiency and solve related problems.

Answer 4

Efficiency is the ratio of useful energy output to total energy input (Efficiency = Useful Energy Output/Total Energy Input).