Achild drops a ball from a bridge. the ball strikes the water under the bridge 2.0 seconds later. what is the velocity of the ball when it strikes the water?

Air is to be preheated by hot exhaust gases in a cross-flow heat exchanger before it enters the furnace. air enters the heat exchanger at 95 kpa and 20°c at a rate of 0.6 m^3/s. the combustion gases (cp = 1.10 kj/kg°c) enter at 160°c at a rate of 0.95 kg/s and leave at 95°c. determine the rate of heat transfer to the air and its outlet temperature.

5400 j of energy are given off when a 50 g of aluminum pan changes temperature. does the temperature of the pan increase or decrease and by how much?

I’m the absence of a net force, a moving object will