Answer:
The height of the ball, h = 81.63 m
The velocity of the ball at the highest point is zero
Explanation:
Given data,
The mass of the ball, m = 1 kg
The initial velocity of the ball, u = 40 m/s
Using the conservation of energy, the total mechanical energy of the ball initially at u = 40 m/s
E = P.E + K.E
E = 0 + ½ mv²
= ½ x 1 x 40²
= 800 J
The maximum height the ball reaches with the energy E = 20 J
The K.E of the ball is zero at the maximum height
E = mgh
h = E / mg
= 800 / (1 x 9.8)
= 81.63 m
The height of the ball, h = 81.63 m
The velocity of the ball at the highest point is zero.
