A .580kg rock is tied to the end of a string and is swung in a circle with a radius of 0.500 meters. The velocity of the rock is 4.50 m/s. What the centripetal force acting on the rock?

1 Answer
May 4, 2018

The force is 23.49 Newtons.

Explanation:

The two relevant equations here are the equation for centripetal acceleration:

#a = (v^2)/r#

and the equation for force:

#F = ma#

Using these two equations, your answer can be easily derived.

First, we determine the acceleration of the object using the equation for centripetal acceleration. We already know the velocity of the object and the radius of the circle, so the calculation is easy

#a = (v^2)/r = (4.5)^2/0.5 = 20.25/0/0.5 = 40.5 m/s^2#

Next, we plug this into the force equation:

#F = ma = 40.5*0.58 = 23.49 N#

The reason the final answer is in Newtons is that anytime you have an acceleration (measured in #m/s^2#) multiplied by a mass (measured in #kg#) the resulting unit is Newtons.