PHYSICS · Multi-part · A Level · Physics · Mechanics and materials · Mechanics and materials
Problem
A 0.40kg laboratory cart rolls at 5.0ms−1 on a level, frictionless track and collides with and sticks to a 0.60kg cart that is initially at rest at the base of a smooth ramp. Immediately after the collision, the coupled carts move together up the ramp until they momentarily come to rest at a maximum height above the track.
(a) Determine the speed of the coupled carts immediately after the collision.
(b) Calculate the maximum vertical height the carts reach on the ramp.
(c) Compute the kinetic energy of the system (i) just before impact, (ii) just after impact, and (iii) at the highest point on the ramp. Using these values, find the amount of mechanical energy converted to non-mechanical forms during the collision.
(d) Explain why mechanical energy is conserved during the carts’ ascent up the ramp but not during the collision itself. In your answer, clearly state the role of internal versus external forces in each phase.