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:
False.
Explanation:
Decibels (dB) measure sound levels
Answer:
Probably all but (a)
The Tyndall Effect is caused by dispersion of the incident light by the individual molecules in the liquid.
Salt water and a foggy night will cause dispersion of the incident light.
A soda drink may also cause this dispersion, but and not sure.