A ball is thrown upward with a certain speed. It passes through the same point at 3 second and 7 second from the start. The maximum height achieved by the ball is
1. 500 m
2. 250 m
3. 125 m
4. 450 m
As upward and downward motion are symmetric [Time taken from AB is same as time taken from BC]
So time to reach highest point is 5s. Same time is required to reach from B to ground.
Time to reach highest point after 3sec =
Time to reach highest point from ground = 3+2 = 5sec.
For downward motion,