Question

The spin angular-momentum vector for a spinning wheel is parallel with its axle and is pointed east. To cause this vector to rotate toward the south, in which direction must a force be exerted on the east end of the axle?

Answer 1

Answer: Down

Step-by-step explanation:

We are given that angular momentum is pointed east.

Now, to find the direction of force we use the right hand rule.

According to the rule, if you curl your fingers in direction of rotation i.e. south and thumb points in the direction of resultant vector i.e. east. Your finger will show you the direction of force which is down.

So the force must be exerted in down direction.