Please help with these tysm

During takeoff, the sound intensity level of a jet engine is 170db at a distance of 34 m. what's the sound intensity level at a distance of 1.0 km?

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.

Find the dimensions and area of the largest rectangle that can be inscribed in the upper half of the ellipse. (give your answers in terms of a and b. enter the dimensions as a comma-separated list.)