The speed of light in a material is given by:

where

is the speed of light in vacuum
n is the refractive index of the material
The lens in this problem has a refractive index of n=1.50, therefore the speed of light in the lens is

And the correct answer is C).
Answer:
Explanation: Speed = Wavelength x Wave Frequency. In this equation, wavelength is measured in meters and frequency is measured in hertz (Hz), .
The answer is A. Proton. Protons have the opposite charge to electrons, which have negative charges.
They would be an expert in astronomy
astronomy:the branch of science that deals with celestial objects
here since string is attached with a mass of 2 kg
so here tension force in the rope is given as

here we will have

now we will have speed of wave given as

here we will have


now we know that frequency is given as
F = 100 Hz
now wavelength is given as


so wavelength will be 0.16 m