A 25.0kg child on a 2.00m long swing is released from rest when the ropes of the swing make an angle of 30 degrees with the vertical. (a) Neglecting friction, find the child's speed at the lowest position. (b) If the actual speed of the child at the lowest position is 2.00 m/s, what is the mechanical energy lost due to friction?
(1/2)mvf^2 - (1/2)mvi^2
The Attempt at a Solution
Do I need to use an energy equation to solve for velocity?