A kid is outside his home playing with a metal hoop and stick. He uses the stick to keep the hoop of radius 45.0 cm rotating along the road surface. At one point the hoop coasts downhill and picks up speed.
(a) If the hoop starts from rest at the top of the hill and reaches a linear speed of 9.50 m/s in 11.5 s, what is the angular acceleration of the hoop? (answer in rad/s^2)
(b) If the radius of the hoop were smaller, how would this affect the angular acceleration of the hoop?
~The angular acceleration would decrease.
~The angular acceleration would increase.
~There would be no change to the angular acceleration.