1. The problem statement, all variables and given/known data You do 100 J of work while pulling a child back on a swing, whose chain is 2.0 m long, until the swing makes an angle of 30.0° with the vertical. a) What is the child's mass? (Consider the swing itself and the chain massless) b) Upon releasing the swing from this position, what will the speed of the child be at the bottom of the arc? 2. Relevant equations mgh = 1/2 mv^2 3. The attempt at a solution After doing some trig, I get the height difference of the swing to be 0.267m; we now have h in mgh. since he exerted 100 Js, we set mgh = 100, solving for m m = 38.21 kg now we want to find the speed at the bottom of the arc. we set mgh = 1/2 mv^2 Mass cancels out we solve for V, which should be 2.287 m/s. Can someone verify if my answers are correct?