x= 0 х ko - Fo PES0 Figure CQ13.3

An automobile having a mass of 1000 kg is driven into a brick wall in a safety test. The bumper behaves like a spring with constant 4.75  106 N/m and is compressed 2.70 cm as the car is brought to rest. What was the speed of the car before impact, assuming no energy is lost in the collision with the wall? m/s

A mass of 0.4 kg is held against compressed spring and released from rest while upon a horizontal, frictionless surface. The spring constant of the spring is 890 N/m and the mass leaves the spring with a speed of 7.51 m/s. Assume that the spring pushes the mass across the surface. By what amount was the spring initially compressed relative to its equilibrium position?

A spring with spring constant 20 N/m is compressed a distance of 5.5 cm by a ball with a mass of 208.5 g (see figure below). The ball is then released and rolls without slipping along a horizontal surface, leaving the spring at point A. The process is repeated, using a block instead, with a mass identical to that of the ball. The block compresses the spring by 5.5 cm and is also released, leaving the spring at point A. Each object travels up the incline shown in the figure before coming to rest momentarily. Assume the ball rolls, but ignore other effects of friction. (Assume the ball rolls without slipping up the incline until it comes to rest.)   (a) How high above the starting position is the ball when it comes to rest momentarily? m (b) How high above the starting position is the block when it comes to rest momentarily? m