A ball of mass on a string is rotating about the center axis with a velocity . If the tension force in the string is , what is the radius of the circular path of the ball?

1 answer

To find the radius of the circular path of the ball, we need to analyze the forces acting on it. When an object is rotating in a circular path, it experiences centripetal force, which is provided by the tension in the string.

The centripetal force \( F_c \) required to keep the ball moving in a circular path is given by the equation:

\[ F_c = \frac{m v^2}{r} \]

Where:

  • \( m \) is the mass of the ball,
  • \( v \) is the tangential velocity of the ball,
  • \( r \) is the radius of the circular path.

In this case, the tension in the string \( T \) provides the centripetal force. Thus, we can set the tension equal to the centripetal force:

\[ T = \frac{m v^2}{r} \]

To find \( r \), we can rearrange this equation:

\[ r = \frac{m v^2}{T} \]

This equation gives the radius of the circular path of the ball in terms of its mass \( m \), its velocity \( v \), and the tension \( T \) in the string.