A child does 350 J of work while pulling a box from the ground up to his tree house at a steady speed with a light rope. The tree house is $4.0 \mathrm {~m}$ above the ground. What is the mass of the box?

Question

Quizplus · Accepted Answer

The work done (350 J) is equal to the gravitational potential energy gained by the box, which is $mgh$. Using $mgh = 350 \, \text{J}$ and $h = 4.0 \, \text{m}$, and $g = 9.8 \, \text{m/s}^2$, we solve for $m$: $m = \frac{350}{4.0 \times 9.8} \approx 8.9 \, \text{kg}$.

A Child Does 350 J of Work While Pulling a Box