1. A student in the lunchroom blew into his straw with a force of 0.26N. (This was pre-pandemic.) The column of air that pushed the liquid in the glass had an area of
0.21 cm². If the liquid in the glass pushed upward with a force of 79 N, what was the
area of the liquid at the surface of the glass?

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?