The frequency of the wave has not changed.
In fact, the frequency of a wave is given by:
where v is the wave's speed and 
is the wavelength.
Applying the formula:
- In air, the frequency of the wave is:
- underwater, the frequency of the wave is:
So, the frequency has not changed.
The time taken for the athlete to finish the race is 20 s (Option A)
<h3>What is power? </h3>
Power is simply defined as the rate at which work is done. It can be expressed mathematically as
Power (P) = work (W) / time (t)
But
Work = weight × distance
Therefore,
Power = (weight × distance ) / time
<h3>How to determine the time </h3>
- Mass (m) = 55 Kg
- Acceleration due to gravity (g) = 9.8 m/s²
- Weight = mg = 55 × 9.8 = 539 N
- Power (P) = 5.4 KW = 5.4 × 1000 = 5400 W
- Distance (d) = 200 m
- Time (t) =?
Power = (weight × distance ) / time
5400 = (539 × 200) / t
5400 = 107800 / t
Cross multiply
5400 × t = 107800
Divide both side by 5400
t = 107800 / 5400
t = 20 s
Learn more about power:
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Answer:
Yes
Explanation:
When an object has more mass it takes more gravity to keep it down therefore producing friction which in return reduces the amount of kinetic energy created. A change in an object's speed has an greater effect on its kinetic energy. than a change in its mass has, because kinetic energy is proportional to.
G is the gravitational constant, which is approximately 6.6x10^-11 Nm/s^2. It has the same value regardless of the masses of both objects or the distance between them.
