A stone of mass 20g is released from a catapult whose rubber is stretched through 5cm. If the force constant of the rubber is 200Nm(^{-1}), calculate the speed with which the stone leaves the catapult.
Explanation
½Ke(^{2}) = ½mv(^{6})
½ x 200 x (0.05)(^{2}) = ½ x 0.02 x v(^{2})
v(^{2}) = 25
v = 5 m s(^{-1})