Question
What is the displacement of a point on the wheel of radius R initially in contact with ground when the wheel rolls forward half a revolution?
Solution
Given,
Radius of the wheel = R
When half revolution is made by the wheel, the point of contact moves from point A to C and hence undegoes the displacement 
Distance displaced by the point of contact, AB = 
Perpendicular distance traversed by the body = 2R
Therefore, total distance,
and 
Thus the point of contact undergoes the displacement of magnitude 
making an angle 
with the ground.
