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?
A)8.9 kg
B)5.3 kg
C)6.7 kg
D)8.0 kg

Question

Quizplus · Accepted Answer

The work done to lift the box is equal to the gravitational potential energy gained by the box, which is given by the formula $PE = mgh$, where $m$ is the mass of the box, $g$ is the acceleration due to gravity (approximately $9.8 \mathrm{~m/s^2}$), and $h$ is the height. Given that the work done is $350 \mathrm{~J}$ and the height is $4.0 \mathrm{~m}$, we can solve for $m$ as follows: $350 = m \times 9.8 \times 4$, solving for $m$ gives $m \approx 8.9 \mathrm{~kg}$.

A Child Does 350 J of Work While Pulling a Box