MS1.

- Thermal energy is the energy possessed by particles due to their random motion (1)

MS2.

- Chemical energy (stored in chemical bonds) (1)

- Thermal energy (heat) (1)

MS3.

- Wind turns the turbine blades (1)

- The blades rotate a generator (1)

- This generates electricity in the generator (1)

MS4.

- Sun provides energy to plants (1)

- Plants are eaten by animals (1)

- Animals are eaten by predators, passing on the energy (1)

MS5.

- Uses the equation: Kinetic energy = mgh (1)

- Substitutes values: 0.5 × 0.5 × 10 × 2 (1)

- Final answer: 5 J (1)

MS6.

- Finds kinetic energy gain: (1/2)mv² = (1/2) × 1200 × 30² (2)

- Converts to Joules: 540,000 J (1)

- Final answer: 540,000 J (1)

MS7.

- Friction converts kinetic energy into thermal energy (1)

- Example: Braking a car (1)

MS8.

- Conduction (1)

- Radiation (1)

MS9.

- Refrigerator cools food by removing heat (1)

- Heat is transferred from the food compartment to the outside air (1)

- Prevents bacteria from growing and spoiling the food (1)

MS10.

- Finds temperature change: 100 - 20 = 80°C (1)

- Uses the equation: Energy transferred = mcsΔT (1)

- Substitutes values: 0.25 × 0.39 × 80 (1)

- Final answer: 7.8 J (1)