Question

A ball of mass 1kg is being suspended 10m above the ground & is then dropped. what is the balls kinetic energy just before it hits that ground ?

a. 10 J
b. 98 J
c. 50 J
d. 0 J

Answer 1

E = 98 J

Step-by-step explanation:

Given that,

The mass of a ball, m = 1 kg

It is being suspended 10m above the ground & is then dropped.

We need to find the ball's kinetic energy just before it hits that ground. The conservation of energy holds here. It means, the kinetic energy just before it hits that ground is equal to its potential energy i.e.

`E=mgh\\\\E=1* 10* 9.8\\\\E=98\ J`

so, the required energy is 98 J. Hence, the correct option is (b) "98 J".