Explain the input and output energy sources for a car engine. How would you calculate the efficiency? Explain in terms of the inputs and outputs how the efficiency could be improved.

The input is chemical energy (in the form of fuel). The outputs areSound (not useful)Kinetic (useful)Heat (may be useful)The efficieny is given by useful output energy divided by total input (or output) energy. The efficiency could be increased by reducing the amount of sound and heat produced, which would mean reducing friction within the engine (perhaps by oiling the engine or changing the material it is made from). The efficiency could also be improved by making the wasted outputs useful, by switching on the heaters in the car for example.