Question

An asteroid is moving along a straight line. A force acts along the displacement of the asteroid and slows it down. The asteroid has a mass of 5.4× 104 kg, and the force causes its speed to change from 6500 to 4500m/s. (a) What is the work done by the force? (b) If the asteroid slows down over a distance of 2.4× 106 m determine the magnitude of the force.

Answer 1

Given Data

mass, m = 5.4e4kg

speeds, Vf = 4500 m/s

Vi = 6500 m/s

distance d = 2.4× 106 m

a) work done = ΔKE = ½m(Vf² - Vi²)

                                 = ½ * 5.4e4kg * (4500² - 6500²)m²/s²

                                = -5.94e11 J

b) F = work / d

        = 5.94e-11J / 2.4e6m

        = 2.475e5 N