A 4.0kg shipping crate rests on a long, infinitely-smooth baggage conveyor belt in an airport terminal. At time t=0 the belt, which was previously stationary relative to the ground, instantaneously attains a constant speed of 1.2ms−1 toward the right and then moves at that speed without further acceleration. The coefficient of static friction between the crate and the belt is large enough that the crate never slips relative to the belt.
Ignore any other external forces and answer the following.
(a) Determine the speed of the crate relative to the ground (i) just before t=0 and (ii) just after the belt reaches its constant speed.
(b) Calculate the translational kinetic energy of the crate immediately after the belt reaches its constant speed, as measured by an observer standing on the ground.
(c) Calculate the translational kinetic energy of the crate at the same instant, as measured by an observer riding on the conveyor belt.
(d) Compute the ratio KbeltKground of the two kinetic-energy values you obtained.