A softball of mass 0.3 kg strikes a hard wall perpendicularly with an initial speed of 35 m/s. The softball is in contact with the wall for 0.03 seconds, and then rebounds straight back with a speed of -15 m/s. What average force was applied to the softballby the wall? ​

At what point the certain object feels zero garvitational force between earth and the moon. take the required information from the book.required: distance away from earth or moon

Aforce of 200 n is applied to an input piston of cross-sectional area 2 sq. cm pushing it downward 2.8 cm. how far does the output piston of cross-sectional area 12 sq. cm move upward? show all work.

Acoal-fired plant generates 600 mw of electric power. the plant uses 4.8 x 10^6 kg of coal each day, and the heat of combustion of coal is 3.3x 10^7 j/kg. the steam that drives the turbines is at a temperature of 300° c, and the exhaust water is at 37° c. (a) what is the overall efficiency of the plant for generating electric power? (b) how much thermal energy is exhausted each day? (c) what is the change in entropy of the universe for this heat engine? (d) using the same heat reservoirs, what is the maximum possible (carnot) efficiency for a heat engine?