Problem 1
If the force exerted by the intern is doubled and the distance is halved, does the work done by the intern increase, decrease, or remain the same?
Problem 2
There is a species of Darwin’s finch on the Galapagos Islands that can exert a force of 205 N with its beak as it cracks open a seed case. If its beak moves through a distance of 0.40 cm during this operation, how much work does the finch do to get at the seed inside the case?
Problem 3
Early one October you go to a pumpkin patch to select your Halloween pumpkin. You lift a 3.2-kg pumpkin to a height of 0.80 m to check it out. How much work do you do on the pumpkin when you lift it from the ground?
Problem 5
A parent pulls a child in a little red wagon with constant speed. If the parent pulls with a force of 16 N for 12 m and the handle of the wagon is inclined at an angle of 25 above the horizontal, how much work does the parent do on the wagon?
Problem 6
The frictional force acting on the drum set does negative work. Does friction always do negative work? If yes, explain why. If no, give an example of friction doing positive work.
Problem 7
You slide a 0.12-kg coffee mug 0.15 m across a table. The force you exert is horizontal and of magnitude 0.10 N. The coefficient of kinetic friction between the mug and the table is 0.05. How much work is done on the mug?
Problem 7
You slide a 0.12-kg coffee mug \(0.15 \mathrm{~m}\) across a table. The force you exert is horizontal and of magnitude \(0.10 \mathrm{~N}\). The coefficient of kinetic friction between the mug and the table is \(0.05\). How much work is done on the mug?
Problem 8
How is work calculated when force and displacement are in the same direction?
Problem 9
Which component of force is used to calculate work when the force and the displacement are at an angle to each other?
Problem 10
Is it possible to do work on an object that remains at rest? Explain.
