Power from force, distance, and time

Steps:

• Force F pulls the object horizontally over distance d, so work done W = F × d.
• The motion occurs in time t.
• The expression Fd/t equals W/t.
• By definition, power P is work per unit time, so P = W/t = Fd/t.

Why C is correct:

• Power is the rate of doing work, given by P = W/t where W = Fd for constant force.

Why the others are wrong:

• A: Efficiency is useful work output divided by total energy input, requiring more data.
• B: Energy equals work done Fd, without dividing by time t.
• D: Work is force times distance Fd, not divided by time.

Final answer: C