Question
The tops of the towers of the golden gate bridge in san Francisco, are 227m above the water. suppose a worker drops a 655g wrench from the top of a tower. if the average force of air resistance is 2.20 percent of the force of free fall what will the kinetic energy of the wrench be when it hits the water?
Answers
drwls
I suppose that what they are calling the "force of free fall" is the weight, M g.
Frictional work performed against air resistance while falling will then be
0.022 M g H
Subtract that from M g H to get the kinetic energy when it hits the water.
(1/2) M V^2 = 0.978 M g H
Frictional work performed against air resistance while falling will then be
0.022 M g H
Subtract that from M g H to get the kinetic energy when it hits the water.
(1/2) M V^2 = 0.978 M g H