Speed = (distance covered) / (time to cover the distance).
The speed of anything that covers 42 meters in 7 seconds is
(42 meters) / (7.0 seconds)
= (42 / 7.0) (meters/second)
= 6.0 m/s .
Explanation:
pressure=density of water × gravity ×height
=1000×9.8×20=196,000N/m^2
=196000/1000=196kpa which is almost 200kpa
"Waves can exist in solids, liquids, and gases."
is the ONLY accurate statement.
The word "only" in the other 3 statements makes them
not accurate at all.