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.

Respuesta :

Answer:

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

[tex]v=2.5 m/s[/tex]

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

[tex]t=\frac{d}{v}=\frac{12.5}{2.5}=5 s[/tex]

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

[tex]s=\frac{1}{2}gt^2[/tex]

where

[tex]g=9.8 m/s^2[/tex] is the acceleration due to gravity

Therefore, substituting t = 5 s,

[tex]s=\frac{1}{2}(9.8)(5)^2=122.5 m[/tex]

So, the height of the building is 122.5 m.