A tuning fork has a frequency of 400 Hz and hence a period of 2.50 10-3 s. If the tuning fork is in an inertial frame of reference moving by the observer at speed of 0.680c, what is the frequency of the fork as measured by the observer? (Assume that measurements are strictly by optical means and that the speed of sound waves in air is not pertinent here.)
a. 454 Hz
c. 605 Hz
b. 293 Hz
d. 265 Hz
Question 2
The period of an oscillating weight on a spring in an inertial frame of reference is 0.80 s. What would be its speed if it were to move by an observer who measures its period as 1.2 s? (c = 3.00 108 m/s)
a. 2.5 l08 m/s
c. 2.9 108 m/s
b. 1.1 l08 m/s
d. 2.2 108 m/s