Answer:

Explanation:
R = Horizontal range of projectile = 75 m
v = Velocity of projectile = 37 m/s
g = Acceleration due to gravity = 
Horizontal range is given by

The angle at which the arrow is to be released is
.
D. Equal to zero.
Because the forces balance each other.
The mechanical work done by the sprinter during this time will be 4537.5 J , the average power the sprinter must generate will be 907.5 W and if the sprinter converts food energy to mechanical energy with an efficiency of 25% then he will be burning calories at 54.20 calories per second.
Work in physics is the energy that is transferred to or from an item when a force is applied along a displacement. It is frequently described in its most basic form as the result of force and displacement.
The quantity of energy moved or transformed per unit of time is known as power in physics. The watt, or one joule per second, is the unit of power in the International System of Units.. A scalar quantity is power.
Given 75-kg sprinter accelerates from rest to a speed of 11.0 m/s in 5.0 s.
So let,
m = 75 kg
v = 11.0 m/s
t = 5.0 s
So the mechanical work done by the sprinter during this time will be as follow:
W = 0.5 mv²
W = 0.5 (75)(11)²
W = 4537.5 J
The average power the sprinter must generate will be as follow:
Power(P) = W / t
P = 4537.5/5
P = 907.5 W
Only 25% is absorbed. So, the sprinter only absorbed 226.875 J per second which is equal to 54.20 calories per second.
Hence mechanical work done by the sprinter during this time will be 4537.5 J , the average power the sprinter must generate will be 907.5 W and if the sprinter converts food energy to mechanical energy with an efficiency of 25% then he will be burning calories at 54.20 calories per second.
Learn more about mechanical power here:
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Warm water<span> has more energy </span><span>than cold water</span>