Question

An ice puck of mass m revolves on an icy surface in a circle at speed v at the end of a horizontal string of length L. The tension in the string is T. What is the mass of the puck if the length of the string is 2 m, the string tension is 10 N, and the tangential speed of the puck is 2 m/s.

Answer 1

`m=5kg`

Step-by-step explanation:

According to the Newton's second law, in this case, the tension is equal to the mass multiplied by the centripetal acceleration, since is a circular motion.

`T=ma_c`

The centripetal acceleration is given by:

`a_c=(v^2)/(r)`

Here r is the radius of the circular motion, in this case is equal to the length of the string. Replacing and solving for m:

`T=m(v^2)/(L)\\m=(TL)/(v^2)\\m=(10N(2m))/((2(m)/(s))^2)\\m=5kg`