Question

A girl is sitting on the edge of a merry-go-round at a playground. Looking down at the merry-go-round from above, it is rotating clockwise. What is the direction of the girl’s angular velocity vector?

	a.	counter-clockwise
	b.	clockwise
	c.	upward
	d.	downward

If an object is rotating with a constant angular velocity, the instantaneous angular velocity and the average angular velocity ...

	a.	are always the same.
	b.	always have the same magnitude but only sometimes have the same direction.
	c.	are never the same.
	d.	always have the same direction but only sometimes have the same magnitude.

An object has a positive angular velocity when it is spinning ...

	a.	in the counter-clockwise direction.
	b.	in the clockwise direction.
	c.	according to the right hand rule.
	d.	according to the left hand rule.

Answer 1

Q(1)Ans. (d) downward

According to right hand rule, if you hold the axis with your right hand and rotate the fingers in the direction of motion of the rotating body then thumb will point the direction of the angular velocity. The direction of angular velocity is above or below the plane.

Q(2)Ans. (a) are always the same.

Q(3)Ans. (a) in the counter-clockwise direction.

by convention, counterclockwise is the positive direction and clockwise is the negative direction.