How can the total horizontal force on a rolling ball be shown to be zero?

[Logarythmic]

How can I show that when a ball is rolling without slipping on a horizontal plane, the total horizontal force on the ball must be zero?

I guess I should consider the ball as a rigid body and combine the equations describing the rotation with the rolling constraints, but how? Can someone give me a starter here?

 

[berkeman]

The statement is not correct. I think you meant to say that it is rolling at a constant velocity without slipping. If it's translational and rotational velocities are constant, then what can you say about F=ma?

But you can definitely accelerate a ball on a horizontal plane by applying a net force...

 

[Logarythmic]

The problem says nothing about constant velocity, just that the ball is constrained to move on a horizontal plane. Otherwise, a = 0 and F = 0.

 

[KoGs]

When the ball is not slipping, you can say something about the normal force.

 

[Logarythmic]

Yeah, equal to mg?

 

[tim_lou]

edit: nevermind.