Question

A ball is thrown horizontally from the top of a building and strikes the sidewalk after 2.8 s. How tall is the building? Neglect air resistance.

Answer 1

Answer:

h = 38.41 m

Explanation:

Given that,

A ball is thrown horizontally from the top of a building and strikes the sidewalk after 2.8 s.

We need to find the height of the building. Let it is h.

Initial speed of the ball, u = 0

Using second equation of motion to find h as follows :

$h=ut+\dfrac{1}{2}at^2\\\\\text{Put u = 0 and a = g}\\\\h=\dfrac{1}{2}gt^2\\\\=\dfrac{1}{2}\times 9.8\times 2.8^2\\\\=38.41\ m$

So, the building is 38.41 m tall.