Question

A person spins a tennis ball on a string in a horizontal circle (so that the axis of rotation is vertical). At the point indicated below the ball is moving in the z direction (out of the page) and is given a sharp blow vertically downward (-y direction). In which direction does the axis of rotation tilt toward after the blow
a. x- direction
b. y- diraction
c. z- direction

Answer 1

Answer:

direction does the axis of rotation tilt toward after the blow is the z- direction

Explanation:

This is because

Due to the blow, there is a impulse imparted on the ball which gives a change in linear momentum () in the x direction

Thus When cross product of momentum in x direction is taking with r vector, we will get resultant in z direction. Hence change in angular momentum will be z direction.