A 10 kg rock that has been dropped from a 60 meter high cliff experiences an average force of air resistance of 30 N. Calculate the KE at the bottom of the fall.

4086 J

Explanation:

The potential energy is transformed to kinetic energy less the frictional energy. Potential energy= mgh where m represent mass, g is acceleration due to gravity and h is the height of cliff

Since we have force of air resistance, work done due to air resistance will be product of force and distance

Substituting 10 Kg for m, 9.81 for g and 60 m for F then the kinetic energy at the bottom will be

KE= 10*9.81*60- (30*60)=4086 J

the answer is c.)

explanation:

change tension