# Simple Mechanics problem - rotating the rod with a ball attached on a string

#### Curiousphysicist

To the end [A] of the rod [AB] with a length of d = 1.35 m a thin string with a length of l = 1.16 m was attached, at the other end of which a ping-pong ball is attached. The bar began to rotate in a horizontal plane with a constant angular velocity ω = 2.08 / s around the end B. Find the radius of the circle along which it will move.
Ignore the weight of the ball and string and the air resistance acting on the thread, but take into account the air resistance acting on the ball.

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#### ChipB

PHF Helper
I’d be glad to help, but first please show us your attempt at solving this and where you are getting stuck. Here’s a hint: start by drawing the free body diagram for the ping pong ball.

2 people

#### Curiousphysicist

I’d be glad to help, but first please show us your attempt at solving this and where you are getting stuck. Here’s a hint: start by drawing the free body diagram for the ping pong ball.
Sure thing. I'll post shortly what I came up with.