A 15 kg box is given an initial push so that it slides across the floor and comes to a stop. If the coefficient of friction is 0.30 a)find the friction force
b)find the acceleration of the box. Hint: what is the net force as the box slides to a stop?c)how far will the box go if its initial speed is 3.0 m/s?

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?