Direction of the frictional force

[rootX]

Homework Statement

http://docs.google.com/TeamPresent?docid=dm9wjvk_10fk863j&skipauth=true

In the above file, a force at the top of the wheel is acting towards, right, and the friction at the bottom towards left.

But shouldn't the frictional force at the bottom point towards right?

Homework Equations

NA

The Attempt at a Solution

Second question: if a ball is rolling up an inclined plane, does the friction points upwards?
as it is slowing down the angular velocity so that the ang. velocity could be equal to the linear velocity that is being
slowed down by the gravity.

NA

 

[Shooting Star]

The dirn of the frictional force will always be as to prevent slippage between the surfaces of the ball and the surface it's rolling on.

1. You're right.
2. Again, toward the dirn of the movement of the ball. Gravity is slowing down the ball.

 

[rootX]

Thanks,

I would further confirm this with my professor. Two professors(ours and one who has made those notes) told us that friction is that way.