Defined as how much energy it takes to perform a specific amount of work.

a.) machine
b.) friction
c.) efficiency
d.) mechanical advantage

Defined as how much energy it takes to perform a specific amount of work.

B. Friction

I think the best answer from the choices listed above is option B. Friction force is defined as how much energy it takes to perform a specific amount of work since it is the only force among the choices listed above. Hope this answers the question.

As we gain mass the force of gravity on us increases!

A. absolute mark as brainliest