Weight is the most closely related object to mass.
Answer: A
Wavelength and frequency of light are closely related. The higher the frequency, the shorter the wavelength. Because all light waves move through a vacuum at the same speed, the number of wave crests passing by a given point in one second depends on the wavelength.
The answer to this question is 3.69
just analyze it in this way:
20cos30*=10( radical 3 )
20sin30*=10
We have to see the diagram luv