Question

A stone is released from the top of a tower of height 19.6m.Calculate​ it's final velocity just before touched the ground.

Answer 1

Answer :

Height of tower = 19.6 m

Initial velocity = zero

We have to find final velocity of stone just before it touched the ground$.$

★ Since constant acceleration due to gravity continuously acts on the stone throughout the motion, we can apply equation of kinematics to solve this question.

For a body falling freely under the action of gravity, g is taken positive.

Third eq. of kinematics is given by

• v² - u² = 2gH

H denotes height of tower

u denotes initial velocity

v denotes final velocity

g denotes acceleration

➠ v² - u² = 2gH

➠ v² - 0² = 2 × 10 × 19.6

➠ v² = 392

➠ v = 19.8 m/s