a question about momentumA pile driver of mass 100 kg, used on a building site, is hoisted 10 m above a steel pipe of mass 400 kg before being released, as shown in Fig.8. If the resistive force exerted by the ground on the pile is 250,000 N, approximately how far does the 100 kg mass drive the pile into the ground? (You may use the approximation g = 10 ms?2.)
potential energy in the hoisted pile driver = mgh = 100kg * 10m/s^2 * 10 m This equals the work done by the pile driver: work = force * distance = 250,000 kg m/s^2 * d where d is distance. Thus 100kg * 10m/s^2 * 10 m = 250,000 kg m/s^2 * d Solve for d: d = 100kg * 10m/s^2 * 10 m/(250,000 kg m/s^2) d=.04 m = 4 cm
