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.
A river d km wide is flowing at a rate A swimmer which can swim with velocity relative to water, dives into the river perpendicular to the direction of flow to cross the river. How far he will go down the river along the river?