Question

A 1.40 kg squirrel runs east across the ground for 7.00 meters. She climbs 0.650 meters before running west on a limb for 4.50 meters. She jumps up 0.990 meters onto another branch, travels west 4.55 meters. She stops and eats a nut. Calculate net work. 

Answer 1

The total work done against gravity is equal to

$$W = mgh$$

where $m = 1.4kg$ is the mass of the squirrel, $g = 9.8m/s^2$ is the gravitational acceleration, and $h$ is the total heigth change. From the problem statement we can find, that

$$h = 0.650m + 0.990m = 1.64m$$

Thus, the net work is

$$W =1.4kg\cdot 9.8m/s^2\cdot 1.64m \approx 22.5J$$

Answer. 22.5 J