A stone dropped from the top of a tower of height 300 m splashes into the water of a pond near the b

Question

A stone dropped from the top of a tower of height 300 m splashes into the water of a pond near the base. When is the splash heard at the top? (Speed of sound in air = 340 m/s, $g = 9.8 	ext{ m/s}^2$)

Professor PC Thomas Classes · Answer

Time taken for the stone to fall $t_1 = \sqrt{2h/g} = \sqrt{2 	imes 300 / 9.8} = 7.82$ s. Time taken for sound to travel up $t_2 = h/v = 300 / 340 = 0.88$ s. Total time = $7.82 + 0.88 = 8.7$ s.