A 6.0 kg block initially at rest is pulled to the right along a horizontal, frictionless surface by a constant, horizontal force of 12 N. Find the speed of the block after it has moved 3.0 m.  And. V = 3.16 m/s

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.