Question

How much kinetic energy does a 2000 gram ball have the instant before it hits the ground after falling from a height of 6 meters?

Answer 1

117.6J

Step-by-step explanation:

Given parameters:

Mass of ball = 2000g

Height = 6meters

Unknown:

Kinetic energy before it comes to rest = ?

Solution:

The potential energy of a body is the energy at rest of a such a body. It is given as:

P.E = mgh

The kinetic energy is the energy due to the motion of a body;

K.E =
`(1)/(2)` m v²

m is the mass

g is the acceleration due to gravity = 9.8m/s²

h is the height

v is the velocity

According to the conservation of energy,

maximum kinetic energy when the ball will be just about to hit the ground = Maximum potential energy

At the point where ball is about to hit the ground;

K.E = P.E

convert the mass to kg = 2kg

K.E = mgh = 2kg x 6m x 9.8 = 117.6J