Question

The work energy principle states that the change in kinetic energy of an object is equal to the net work done on the object. If you drop an object in class from some height what will the final velocity of the object be? Assume there is no air resistance, and use the insert math equation (sqrt x above) to put in your answer.

Answer 1

Answer:

$v=\sqrt{2gh}\ m/s$

Explanation:

From work energy theorem

Work done by all forces = Change in kinetic energy

Lets take

m= mass of object

h=height from the ground surface

initial velocity of object = 0 m/s

The final velocity of object is v

Work done by gravitational force = m g . h

The final kinetic energy = 1/2 m v²

So

Work done by all forces = Change in kinetic energy

m g h =  1/2 m v² - 0

v² = 2 g h

$v=\sqrt{2gh}\ m/s$