While running, a person dissipates about 0.60 J of mechanical energy per step per kilogram of body mass. If a 52-kg person develops a power of 80 W during a race, how fast is the person running

The person is running at a speed of 2.564 m/s

Explanation:

Given;

mechanical energy dissipated per kilogram per step, E/kg/S = 0.6 J/kg/S

mass of the person, m = 52 kg

power developed by the person, P = 80 W

mechanical energy of the person per step, E = 0.6 J/kg x 52 kg

                                                        = 31.2 J

mechanical energy for the total step, = 31.2 J x S

P = E / t

Therefore, the person is running at a speed of 2.564 m/s

since you're a real machine, your ama is always less than your ima, because you can never totally eliminate friction.

here we know that ball will drop down by total distance 3.2 m

so here we know that

now using kinematics

now in the same time it will cover horizontal distance of 0.75 m

so speed of the ball will be