1. The problem statement, all variables and given/known data An object of mass m is suspended from the top of a cart by a string of length L. The cart and object are initially moving to the right at a constant speed vi. The cart comes to rest after colliding and sticking to a bumper, and the suspended object swings through an angle θ. (a) Show that the initial speed is vi = sqrt 2gL(l-cosθ). (b) If L = 2.0 m and θ = 40.0°, find the initial speed of the cart. 2. Relevant equations KE = PE 1/2mv2 = mgh L1= L-(Lcosθ) 3. The attempt at a solution 1/2mv2 = mgh v2 = 2mgh/m v = sqrt 2gh stuck!