a stone is dropped from the top of a tower 490m high into a pond of water at the base of the tower the Splash is heard after (g = to 9.8 m/s² speed of sound = 350m/s)​

Using Formula s=ut+ 1/2 at²

                       490 = (0)t + 1/2 (9.8) t²

                       490 = 1/2 (9.8) t²

                        t² = 490 X 2/9.8

                        t² = 980/9.8

                        t² = 100

                        t = 10s

The stone will reach the pond in 10 secs

Now we shall find the time taken by the sound to reach our ears:

 time= distance/speed

        = 490/350

        = 1.4

Therefore the final answer is 10 + 1.4 seconds = 11.4seconds