Answer: Mechanical waves
Explanation:
Mechanical waves require a medium in order to transport their energy from one location to another. A sound wave is an example of a mechanical wave. Sound waves are incapable of traveling through a vacuum.
The distance starting from the point to the lighthouse would be regarded as the hypotenuse.
And also will be the radius of the circle the beam of light is generating at that point.
So get the radius first
r = sqrt (1^2 + 5^2)
r = 5.099 km
find the circumference:
C = 2*pi * 5.099 km
C = 2 * 16.01898094
C = 32.04 km
Then find the speed in km/sec
One revolution: 60/2 = 30 sec per revolution
Speed = 32.04 km/30 sec
S = 1.068 km/sec is the speed of light
The correct answer would be A