A30-kg child starts at the center of a playground merry-go-round that has a radius of 2.1 m and rotational inertia of 500 kg⋅m2 and walks out to the edge. the merry-go-round has a rotational speed of 0.20 s−1 when she is at the center?

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.