# Questions about circular motion/ centripetal acceleration/force

1. Homework Statement
a 20 kg ball attached to a string is moving in constant circular motion. if theta= 10 degrees and the radius of its circular path is 0.5 m, what is the ball's velocity?

2. Homework Equations
a(centripetal)=V^2/r

3. The Attempt at a Solution

As far as I got was F(net)=F(centripetal), then I was lost

## Answers and Replies

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1. Homework Statement

As far as I got was F(net)=F(centripetal), then I was lost
What forces are on your ball? (draw it and then an fbd)

Oh! The teacher told the class that there are only two forces acting on the ball. There is F(centripetal) and there is F(gravity) which is 196 N I got that from the information. What is an fbd?

What is an fbd?
Free Body Diagram~ it's where you draw the object (or usually just a dot to represent it) and use arrows on it to represent the forces.
Also, the centriptial force is not a new force (the name is misleading), its the net force of a circular motion problem. Certain forces on the object (like weight, etc) cause the circular motion, which results in an overall net force that makes the object go in a circle. (circular overall net force = centripital force). So what forces make your object go in a circle?

Oh! The teacher told the class that there are only two forces acting on the ball. There is F(centripetal) and there is F(gravity) which is 196 N I got that from the information. What is an fbd?
Yes, there's a weight component, and there's a centripetal force, but there's also tension. How can you relate these three?

rock.freak667
Homework Helper
1. Homework Statement
a 20 kg ball attached to a string is moving in constant circular motion. if theta= 10 degrees and the radius of its circular path is 0.5 m, what is the ball's velocity?
It appears the string is at an angle...while another force is perpendicular to the object... If the object doesn't move up or down, doesn't that mean that something is balancing out the force? If so, how does a Force at an angle balance it out? (think vectors)