Aship sends out a pulse of sound and receives an echo back one second later. if the water is 750m deep, what is the speed of sound in water?

1500 m/s

Explanation:

The sound wave travels 750 meters from the ship to the bottom of the water, then 750 meters back to the ship.  So it travels a total distance of 1500 meters in 1 second.

So the average speed is:

v = 1500 m / 1 s

v = 1500 m/s

positive reinforcement? ?

answer: 2×10^-2kg

explanation: density= mass per volume

vol=mass/density

converting to s.i units we have;

3÷1000kg = 0.003

1.5÷100m = 0.15

0.003/0.15 = 0.02kg