1) If you create a 1 ms light pulse by turning a flashlight on and off, how long will the pulse take to reach the other

[answerhappygod]

1) If you create a 1 ms light pulse by turning a flashlight on
and off, how long will the pulse take to reach the other side of
the room 20 m away (in air at standard temperature and pressure)?
What is the length, in metres, of the pulse?
2) Light travels approximately 300 million metres per second in
air, and if the distance L is 2 m, what would be the minimum
requirement for the oscilloscope’s measurement capability? What are
the disadvantages if you modulate the light beam with a very high
or very low frequency?
3. a). What is the frequency of a red HeNe laser with
wavelength 633 nm?
b) Assuming that the mirror is moving at a speed of 5 cm/s
what is the fractional change in the frequency of a reflected HeNe
laser beam and hence how much of a frequency shift does this amount
to.
c) Explain how the beams will give rise to a beat note on
the detector and explain how you can use the beat note frequency to
infer the speed of the moving mirror (give a conversion
formula)