Answer:
6.4m/s
Explanation:
The total mechanical energy of the man is 1780J.
This mechanical energy is the energy due to the motion of the body and it is a form of kinetic energy.
Also, mass = 87kg
Kinetic energy = [tex]\frac{1}{2}[/tex] m v²
m is the mass
v is the velocity
1780 = [tex]\frac{1}{2}[/tex] x 87 x v²
v² = 40.9
v = 6.4m/s