Question1
A dolphin located in sea water at a temperature of 21?C emits a sound directed toward the bottom of ocean 148 m below.
How much time passes before it hears an echo? Imagine the speed of sound in sea water is 1530 m/s at this temperature. Reply in units of s
Question2
A gun shoots bullets that leave muzzle with the speed of 332 m/s. If a bullet is to hit a target 133 m away at the level of the muzzle, the gun must be aimed at a point above the target. How far above the aim is this point? (Ignore air resistance.)
Question3
A cannon with a muzzle speed of 1000 m/s is used to start an avalanche on a mountain slope. The aim is 2000 m from the cannon horizontally and 800 m above the cannon. At what angle (in degrees and three significant figures), above the horizontal, must the cannon be fired?