Question

A ball is thrown vertically upwards with velocity of 20
m/s from top of multistorey building 30 m high. How
high will the ball rise above ground (g = 10 ms-2)?
40 m
45 m
50 m
60 m​

Answer 1

Answer:-

50m

Explanation :-

It is given that a ball is thrown upwards with a velocity of 20m/s from the top of a multistorey building whose height is 30m. And we have to find the height to which the ball rises above the ground.

Firstly, let's calculate the maximum height reached by the ball when it is thrown vertically upwards from the building.

In this case:-

• Final velocity of the ball will be zero.

• Acceleration due to gravity will be

-10m/s² as ball is going against gravity.

=> v² - u² = 2gh

=> 0 - (20)² = 2(-10)h

=> -400 = -20h

=> h = -400/-20

=> h = 20m

Hence, the height to which the ball rises above ground will be :-

Height of the building + Max height

reached

= (30 + 20) m

= 50m

Thus, the ball will rise to a height of 50m above the ground.