Question

"Suppose you tie a rock to the end of a 0.96 m long string and spin it in a horizontal circle with a constant angular velocity of 20.25 rad/s. If the tension in the string is 970 N, what is the mass of the rock (ignore gravity)

Answer 1

Answer:

The mass of the rock is  $m = 2.46406 \ kg$

Explanation:

From the question we are told that

   The length of the string is  $l = 0.96 \ m$

    The angular velocity is  $w = 20.25 \ rad/s$

     The tension on the string is $T = 970 \ N$

Generally the centripetal force acting on the rock is mathematically evaluated as

       $T = mlw^2$

making m the subject of the formula

      $m = \frac{T}{w^2 * l}$

substituting values

     $m = \frac{970}{(20.25^2) * (0.96)}$

     $m = 2.46406 \ kg$