Aball of mass is moving along +x direction with velocity and strikes another ball of mass which is at rest. after collision, the first ball comes to rest while the second ball breaks into two equal pieces. one of the pieces start moving along +y direction with speed . what will be the velocity of the second piece

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?