A5.10-kg watermelon is dropped from rest from the roof of a 24.0-m -tall building and feels no appreciable air resistance.
calculate the work done by gravity on the watermelon during its displacement from the roof to the ground.
part a
calculate the work done by gravity on the watermelon during its displacement from the roof to the ground.
part bjust before it strikes the ground, what is the watermelon's kinetic energy?
part cjust before it strikes the ground, what is the watermelon's speed?
part dwould the answer in part a be different if there were appreciable air resistance?

Part a)

Part B)

Part C)

Part D)

no change in answer of part A) if there is air resistance in that problem.

Explanation:

Part A)

Work done by the gravity is given as

now we have

m = 5.10 kg

H = 24 m

now we will have

Part B)

As per work energy theorem we can say that work done by all forces = change in kinetic energy of the system

So we will have

Part C)

Now we know that the kinetic energy is given as

Part D)

Work done by gravity only depends on force due to gravity and its displacement so there will be no change in answer of part A) if there is air resistance in that problem.

unlike poles attract

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