Answer:
5 m
Explanation:
We'll begin by calculating the original potential energy. This can be obtained as follow:
Mass (m) = 0.2 Kg
Height (h) = 20 m
Acceleration due to gravity (g) = 10 m/s²
Energy (E₀) =?
E₀ = mgh
E₀ = 0.2 × 10 × 20
E₀ = 40 J
Next, we shall determine the new energy of the ball.
Energy (E₀) = 40 J
Energy lost (Eₗ) = 30 J
New energy (E) =?
E = E₀ – Eₗ
E = 40 – 30
E = 10 J
Finally, we shall determine height of the ball on rebound. This can be obtained as follow:
New energy (E) = 10 J
Mass (m) = 0.2 Kg
Acceleration due to gravity (g) = 10 m/s²
Height (h) =?
E = mgh
10 = 0.2 × 10 × h
10 = 2 × h
Divide both side by 2
h= 10 / 2
h = 5 m
Thus, the height of the ball on rebound is 5 m