The free-rolling ramp has a weight { W }_{ r } . If the crate, whose weight is { W }_{ c } , is released from rest at A, determine the distance the ramp moves when the crate slides a distance d down the ramp and reaches the bottom B. Given: { W }_{ r } = 120 lb , a = 3 , b = 4 , { W }_{ c } = 80 lb , d = 15 ft , g = { 32.2ft/s }^{ 2 }