A man throws ball into the air one after the other. Throwing one when other is at the highest point. How high the balls rise if he throws twice a second.

Options

A. 2.45 m
B. `1.25 m`
C. `19.3 m`
D. `4.9 m`

Answer

B

Explanation

Time taken by the ball to reach the highest point `= 1/2 `sec
Using ` v= u + at`
` o= u-10 xx 1/2`
` u=5 ms^(-1)`
Also ` v^2 -u^2 = 2 a s`
or `0 (5)^2 = 2 (-10) S`
` therefore s= 1.25 m`