Question

a ball is dropped from a height of 20 cm. Ball rebounds to a height of 10 cm. Ball rebounds to a height of 10 cm. what is the loss of energy​

Answer 1

Answer:

See,

Energy = mgh

= mg ×20

Rebound Energy = mg ×10

So,

Loss of Energy is 10/20×100

=50%

Answer 2

Thus, the loss of energy is 100%

Step by Step explanation:

Height from the ball dropped, H = 20 cm = 0.2 m

Height Rebound, h = 10 cm = 0.1 m

Let the mass of object is m.

The formula for the potential energy is given by

U = m x g x h

where, g be the acceleration due to gravity.

Initial potential energy

Ui = m x g x H = m x g x 0.2 = 0.2 mg

Final potential energy

Uf = m x g x h = m x g x 0.1 = 0.1 mg

Loss in potential energy

U = Ui - Uf = 0.2 mg - 0.1 mg = 0.1 mg

Percentage loss in energy

U / Ui x 100 = 0.1 mg / 0.1 mg x 100 = 100 %

Thus, the loss of energy is 100%.