A stone of mass 0.50kg is tied to the end of a light string of length 0.30m and whirled in a horizontal circle with uniform speed.
a. (i) Calculate the centripetal force acting on the stone when its speed is 4.0ms−1.
b. (ii) The speed of the stone is now doubled while the radius of the circle remains unchanged. Determine the new value of the centripetal force.
c. (iii) By what numerical factor has the centripetal force changed as a result of doubling the speed? State the reason for this factor based on the mathematical form of the relevant expression.