Question

A box with the mass of 20 kg at 5 m is lifted to 20 m. How much work was 7 points done?

Answer 1

Answer:

$2,900\: \mathrm{J}$

Explanation:

Work is given by the equation $W=F\Delta x$ where $F$ is force and $\Delta x$ is displacement.

Displacement is defined as change in position. In this case, the box moves from 5m to 20m. Its displacement is $20-5=15\:\mathrm{m}$.

The force acting on the box is the force of gravity, given as $F_g=mg$.

Therefore, the total work done is:

$W=F\Delta x=mg\Delta x = 20\cdot 9.81\cdot 15=2,943=\fbox{ 2,900\:\mathrm{J} }$(two significant figures).