A tractor of mass 5.0*10^3kg is used to tow a car of mass 2.5*10^3kg.the tractor moved with a speed of 3.0m/s^1 just before the towing rope became taut.calculate:the speed of the tractor immediately the rope becomes taut.. lost ke of the system just after the car has started moving..impulse on the rope when it jerks the car back into motion

Answer 1

initial momentum = 5*10^3 * 3 = 15 *10^3
final momentum = 7.5*10^3 v
v = 15/7.5 = 2 m/s
initial Ke = .5*5*10^3 * 9 = 22.5 *10^3Joules
final Ke = .5 * 7.5*10^3*4 = 15*10^3 Joules
loss = 7.5*10^3 Joules
impulse = Force*time = change in momentum of car
= 2.5 * 10^3 * 2 = 5*10^3 kg m/s