A boy fires a 60 g pebble with his slingshot. The pebble leaves the slings hot at 35 m/s. How high above the slingshot will the pebble rise if it is fired straight up?
If the pebble is fired so that it goes in an arc and has a speed of 10 m/s at its maximum height, what will the maximum height be?
At what speed would an 80 g pebble have to be fired to reach the same height as the pebble in (a)? Assume that the 80 g pebble is also fired straight up.

Air enters a gas turbine with two stages of compression and two stages of expansion at 100 kpa and 17°c. this system uses a regenerator as well as reheating and intercooling – the intercooler returns the air to the inlet temperature. the pressure ratio across each compressor is 4 ; 300 kj/kg of heat are added to the air in each combustion chamber; and the regenerator operates perfectly while increasing the temperature of the cold air by 20°c. determine the system’s thermal efficiency. assume isentropic operations for all compressor and the turbine stages and use constant specific heats at room temperature. (0.378)