Question

In machines and engines,A. there will be no friction.B. friction increases fuel efficiency.C. the process of overcoming friction uses valuable fuels.

Answer 1

Friction plays a significant role in machines and engines. The process of overcoming friction uses valuable fuels, making the machines and engines less efficient.

Step-by-step explanation:

Friction plays a significant role in machines and engines. Option C, the process of overcoming friction uses valuable fuels, is correct. Friction occurs due to the interaction between two surfaces, and it opposes the motion of the machine or engine. To overcome friction, energy is required, and this energy comes from the fuel. In the presence of friction, machines and engines become less efficient because some of the energy is lost as heat.

Answer 2

Think of a car, when we have to add oil.  If we didn't then the friction would cause so much heat that the engine would break and fall apart.