1. Imagine a wheel with radius R of 0.34 m and weight of 25
N that sits at rest against the bottom step of a staircase. You
try to raise this wheel one step up. The height of the step H
is 0.12 m. You can either decide to lift the wheel up over a
distance H and put it down on the step, or try to rotate it
around the contact point with the step by pulling on it
horizontally with a force P.
a) If the pulling force is applied in the center of the wheel,
how big is P that will just make the wheel lose contact
with the ground?
b) If the pulling force is applied at the rim of the wheel,
how big is P that will just make the wheel lose contact
with the ground?
c) Discuss the previous two situations when the height of
the step equals the radius of the wheel.
