TeXes Science Practice Test

During combustion in a vehicle's engine, what two types of energy are produced from the chemical energy of fuel?

1. Electrical and Chemical

2. Thermal and Mechanical

3. Radiant and Kinetic

4. Potential and Thermal

The correct answer is: Thermal and Mechanical

The process of combustion in a vehicle's engine converts the chemical energy stored in the fuel into two main forms of energy: thermal energy and mechanical energy. Thermal energy, often referred to as heat, is produced as a result of the combustion reaction. When fuel burns, it releases heat which increases the temperature of the gases inside the engine cylinder. This thermal energy is essential because it helps to expand the gases, creating pressure. Mechanical energy is generated when this expanding gas pushes the piston within the cylinder. This mechanical action converts the energy produced from combustion into motion, ultimately allowing the vehicle to move. This transformation is fundamental in engine operation, making thermal and mechanical energy the primary outputs from the combustion of fuel.