An android robot weighing 50 kg is tested for fatigue strength. He was given the command to jump on one leg

An android robot weighing 50 kg is tested for fatigue strength. He was given the command to jump on one leg (its mass is incommensurably small with the mass of the robot). The height of the jump, measured over the head of the robot, is 5 cm. How long (in seconds) the robot can jump in autonomous mode if 0.5 kWh of electricity is required to fully charge its battery from the electrical network. Acceleration of free fall is taken equal to 10 m / s ^ 2, all energy losses are neglected. The time from the beginning of the moment the robot lands until the moment it starts lifting off the ground at the moment of repulsion is 0.2 s.

m = 50 kg.
g = 10 m / s ^ 2.
h = 5 cm = 0.05 m.
E = 0.5 kW * h = 1800000 J.
t1 = 0.2 s.
t -?
With one jump, the robot spends energy to increase its potential energy: E1 = m * g * h.
When charging the robot, it receives energy E = 1800000 J, which is all used for jumping.
Let’s find the number of jumps of the robot using the formula N = E / E1.
N = E / m * g * h.
Since the time of one jump is t1, the time of all jumps t will be: t = N * t1.
t = E * t1 / m * g * h.
t = 1800000 J * 0.2 s / 50 kg * 10 m / s ^ 2 * 0.05 m = 14400 s = 4 hours.
Answer: the time for the robot to jump is t = 4 hours.