When discussing engines, the ratio of output work to input work expressed as a percentage is called .

Efficiency

Explanation: Efficiency of the engine is defined as percentage of the input work that is converted into output work.

Efficiency = %

Thus if an engine converts all of the input into output, i.e. input work = output work, the efficiency of the engine will be 100%.

But in real scenario, efficiency is always less than 100% as some of the input gets lost in the form of heat, or to overcome frictional forces.

find the surface area of the sphere to the nearest square unit. use a calculator.

a. 254 in.2

b. 64 in.2

c. 127 in.2

d. 1,018 in.2