Question
A ball is dropped from the jumping board of a swimming pool, which is at a height of 20 m. A second ball is thrown from the same board after one second with initial velocity u. Both the balls hit the water together. What was the initial velocity with which the second ball was thrown ? Do they hit water with the same velocity ? Explain your answer.
Solution
(i) Given that,
s = -20 m, u = 0 m/s and g = -10 m/s2
Now, according to the third equation of motion,
ii) Now,
Distance travelled by the ball, s = -40 m
u = 0 and g = -10 m/s2
Now, using the third equation of motion,
