Question

A stone is dropped from the top of a 45 m high building how fast will be moving when it reachs the ground and what is velocity be ?​

Answer 1

Hi there!

`\large\boxed{\text{vf }\approx 29.70 m/s}`

Use the following kinematic equation to evaluate the final velocity:

vf² + vi² + 2ad, where:

vf = final velocity

vi = initial velocity

a = acceleration (due to gravity in this situation, or 9.8 m/s²)

d = distance

Plug in the given values. Note that vi = 0 m/s since the object was dropped from rest:

vf² = 0 + 2(9.8)(45)

Simplify:

vf² = 882

Take the square root of both sides:

√vf² = √882

vf ≈ 29.70