Isn't the normal acceleration always towards the center?

[cipotilla]

Homework Statement

Homework Equations

See attachment

The Attempt at a Solution

I solved the problem (on the same page as problem, written in pencil) but the direction of the acceleration that I calculated is different, I don't understand why my answer is wrong if the normal acceleration always towards the center and the tangent acceleration is suppossed to be clockwise.

 

[Doc Al]

Yes, the radial acceleration is towards the center. But I don't see why you think your solution is different from the book's. Seems to me you are just measuring your angle from a different reference direction--they measure from the horizontal, you from the vertical.

 

[cipotilla]

Yes, the radial acceleration is towards the center. But I don't see why you think your solution is different from the book's. Seems to me you are just measuring your angle from a different reference direction--they measure from the horizontal, you from the vertical.

I think I measured from the horizontal, that's why I think my answer is different from the books, see diagram. Thanks!

 

[Doc Al]

Looks to me like your diagram is sideways, compared to the original diagram given with the problem. What you call "horizontal" appears as vertical in the original diagram.

 

[cipotilla]

You are absolutely right, drew my acceleration vectors on the right side of the pulley, where there is no conveyor belt, that's why I got confused. Ok, thanks you.