Rotational Motion on an Inclined Plane

[UMich1344]

What force does work on a ball as it is rotating down an inclined plane? Explain why the other forces the ball experiences do not do work.

I think the ball experiences gravitational, normal, and frictional forces. Is the force that actually does work on the ball just gravity? I'm having a hard time understanding this concept. Friction is what is causing the rotation, since on a frictionless inclined plane the ball would just slide down. But I don't know how to explain why a given force does or does not do work on the ball.

 

[rock.freak667]

Start with the definition of work.

Work is done when a force moves its point of application in the direction of motion.

With the normal force, is the force and motion in the same direction?

 

[Sniperman724]

I think the frictional force is one of the forces that does work on the ball, I am not quite sure about the other forces

 

[rock.freak667]

I think the frictional force is one of the forces that does work on the ball, I am not quite sure about the other forces

Well on the ball, there is the force down the slope, friction and the normal force.

You are correct that the frictional force does work, would the force down the slope do work?

Remember to see if the force is in the same direction in which the ball is moving.