A2190 kg car moving east at 10.5 m/s collides with a 3220 kg car moving east. the cars stick together and move east as a unit after the collision at a velocity of 4.74 m/s. a) what is the velocity of the 3220 kg car before the collision

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?