This problem is likely the most difficult problem of the exam. Give yourself time to consider thoughtfully, Wheels falling off moving vehicles are rare but documented and dangerous occurences.
The wheel continues to roll, reeking havoc in its path. Assume a 45 kg wheel with radius of 30 cm fell off a truck on top of a 6-m tall hill. The truck was already traveling at 20 m/s when it lost the wheel. Assume the moment of inertia of the wheel is 1 - MR. Determine the linear speed of the wheel when it reaches the bottom of the hill. m/s
Hints:
1) There are linear and rotational Ke terms both before and after rolling down the hill.
2) Use the linear equivalent of angular velocity to simplify rotational terms.
3) Don't plug in numbers until the very end of your work.