A ball is thrown from the top of a building down, which land 12.5m away from the base of the building. How tall is the building.

122.5 m

Explanation:

To solve the problem, we need to know the speed at which the ball has been thrown: here I assumed it has thrown at a speed of

The motion of the ball is a projectile motion, so it consists of two independent motions:

- A uniform motion along the horizontal direction

- A uniformly accelerated motion along the vertical direction

We know that the ball lands at a distance of

d = 12.5 m

away from the base of the building; so the time taken by the ball to cover this distance in the horizontal direction is

The vertical distance covered by the ball is given by the suvat equation

where

is the acceleration due to gravity

Therefore, substituting t = 5 s,

So, the height of the building is 122.5 m.

where is the

b

explanation: