Answer:
6.0 m/s
Explanation:
According to the law of conservation of energy, the total mechanical energy (potential, PE, + kinetic, KE) of the athlete must be conserved.
Therefore, we can write:

or

where:
m is the mass of the athlete
u is the initial speed of the athlete (at the bottom)
0 is the initial potential energy of the athlete (at the bottom)
v = 0.80 m/s is the final speed of the athlete (at the top)
is the acceleration due to gravity
h = 1.80 m is the final height of the athlete (at the top)
Solving the equation for u, we find the initial speed at which the athlete must jump:

Answer: When it comes to energy saving, energy management is the process of monitoring, controlling, and conserving energy in a building or organization. Typically this involves the following steps: Metering your energy consumption and collecting the data.
Explanation:
Answer:
4992 J
Explanation:
Force, F = 39 N
Distance, s = 128 m
Work done = force x distance
W = 39 x 128
W = 4992 J
Thus, the work done is 4992 J.