Afootball punter accelerates a football from rest to a speed of 15 m/s during the time in which his toe is in contact with the ball (about 0.23 s). if the football has a mass of 0.45 kg, what average force does the punter exert on the ball

The difference between a red shift and a blue shift has to do with wavelength frequency. t or f

5g of ammonium nitrate was dissolved in 60g of water in an insulated container. the temperature at the start of the reaction was 23.0°c and at the end it was 19.0°c. calculate the energy absorbed by the reaction.

This energy transformation diagram represents the energy of a skateboarder moving along a half-pipe. as she skates toward the top of the half-pipe, her original kinetic energy is converted to potential energy and friction. how much of the energy is potential?