All of the above.
if your car is on a steep hill it needs force to stop moving and to speed up
The relationship between frequency and wavelength for an electromagnetic wave is

where
f is the frequency

is the wavelength

is the speed of light.
For the light in our problem, the frequency is

, so its wavelength is (re-arranging the previous formula)
Answer: a. Mass per unit length =0.0245kg/m
b. Tension =2.45x10^-8N
C. Tension = 2.45 x10^-8N
Fundamental frequency =200Hz
Explanation:
Answer: Heat waves? I’m not %100 sure