An inflatable raft (unoccupied) floats down a river at an approximately constant speed of 5.2 m/s. a child on a bridge, 63 m above the river, sees the raft in the river below and attempts to drop a small stone onto the raft. the child releases the stone from rest. in order for the stone to hit the raft, what must be the horizontal distance between the raft and the bridge when the child releases the stone?

Awater balloon launcher uses an elastic band with a spring constant of 115 n/m to use thee launcher you stretch thee band back with a balloon n it the water balloons have a mass of 1.3 kg a) if you stretch the band by 0.8 m, what elastic force will the band exert? b) with the band stretched 0.8 m, how much elastic potential energy is stored in the spring? c) if you release the band, it pushes forward. what is the kinetic energy of the balloon when it reaches the natural length of the band? d) what is the speed of the balloon when it reaches the natural length of the band?