An oceanic depth-sounding vessel surveys the ocean bottom with ultrasonic waves that
travel 1530 m/s in seawater.
How deep is the water directly below the
vessel if the time delay of the echo to the
ocean floor and back is 7 s?
Answer in units of m.

What is hidden during a lunar eclipse? isn't the moon hidden?

Can somebody explain to me how newton's 3rd law relates to momentum? ~ap physics 1

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.