- #1
dannie
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A rotating mirror with 16 sides was used to measure the tine it took light to travel 3.5km to a concave mirror and back. At what frequency did the rotating mirror need to turn to make 1/16th of a rotation in the time it took light to travel to 3.5km and back again?
im having a bit of trouble with the second part. is this correct?
d=3.5x10^3m x 2
=7x10^3m
c=speed of light
=3 x 10^8 m/s
c=d/t
t=c/d
t=3x10^8m/s/ 7x10^3m
=4.28x10^4 s
t= 1/8 T
T= t/(1/8)
=4.28x10^4s/(1/8)
=3.42x10^5 s
T=1/f
f= 1/T
=1/(3.42x10^5)
=2.92x10^-6s
im having a bit of trouble with the second part. is this correct?
d=3.5x10^3m x 2
=7x10^3m
c=speed of light
=3 x 10^8 m/s
c=d/t
t=c/d
t=3x10^8m/s/ 7x10^3m
=4.28x10^4 s
t= 1/8 T
T= t/(1/8)
=4.28x10^4s/(1/8)
=3.42x10^5 s
T=1/f
f= 1/T
=1/(3.42x10^5)
=2.92x10^-6s