Test: Energy Dissipation - Year 7 MCQ

The energy stored in gas is chemical, light is also produced but is not the main product. The primary energy transfer in a gas fire is from chemical energy in the fuel to thermal energy (heat) through combustion.

When a ball is dropped, its gravitational potential energy, due to its height, is converted into kinetic energy as it falls.

The thermal (heat) energy is produced by friction between the brake pads and the wheel, converting the cyclist’s kinetic energy into thermal energy.

A microphone converts sound into an electrical signal. This can then be saved to a computer file or amplified and sent through a loudspeaker system so that it can be heard further away.

A solar cell in a calculator converts light energy from the sun or artificial light into electrical energy to power the calculator.

The main energy change for the bus is the conversion of chemical energy (from the fuel) into kinetic energy (to move the bus). Although there are intermediate steps, the desired form of energy for the purpose of moving the bus is kinetic energy.

The electrical signals vibrate a cone in the loudspeaker to produce sound waves.

In the process of converting chemical energy to kinetic energy, some energy is inevitably lost as heat due to the inefficiencies in the system, such as friction between moving parts and heat lost through the exhaust pipe.

When a wind-up clockwork toy is released, the elastic potential energy stored in the wound spring is converted into kinetic energy, causing the toy to move.

The wasted heat energy from the bus engine dissipates into the environment and becomes unusable for further energy conversions, thus being lost as a useful form of energy.