Question

A 4kg brick is dropped from the top of a building whose height is 30m. What is the velocity with which it reaches the ground?

Answer 1

Answer:

The velocity with which it reaches the ground is 24.25 m/s.

Explanation:

Given :

A 4 kg brick is dropped from the top of a building whose height is 30 m.

To find :

the velocity with which it reaches the ground.

Solution :

The initial velocity of the brick is 0 m/s as it is dropped.

Let the velocity with which it reaches the ground be v m/s.

Here, the acceleration, a = g

Using v² - u² = 2as :

v² - 0² = 2 × g × s

v² = 2 × 9.8 × 30

v² = 196 × 3

v = √(196 × 3)

v = 14√3

v = 24.25 m/s

Therefore, the velocity with which it reaches the ground is 24.25 m/s.