Question

An airline executive decides to economize by reducing the amount of fuel, required for long distance flights. He orders the ground crew to remove the paint from the outer surface of each plane. The paint removed from a single plane has a mass of approximately 100 kg.

(a) If the airplane cruises at an altitude of 24,000 m, how much energy is saved in not having to lift the paint to that altitude? (in MJ)

(b) How much energy is saved by not having to move that amount of paint from rest to a cruising speed of 220 m/s? (in MJ)

Answer 1

Part A

Here, the energy saved is the amount of energy required to lift the paint to that height. This is equal to the potential energy gained by the paint when it is at that height.

Part B

In this case, the energy saved is equal to the energy that is the kinetic energy of the paint at that velocity.

Note: Both the answers are in Megajoules(), where

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