Question

A stroboscope is flashing light signals at the rate of 2100 flashes/min. An observer in a rocket ship traveling toward the strobe light at 0.500c would see what flash rate?

Answer 1

speed of Rocket=0.500c

Rate of light signal=2100 flahes/min

Using time dilation equation

$t=\frac{t_o}{\sqrt{1-\frac{v^2}{c^2}}}$

=$\frac{1}{\sqrt{1-\frac{0.25c^2}{c^2}}}$

=$\frac{1}{\sqrt{0.75}}$

=1.154 min

Number .of flashes seen in 1.154 min=$1.154\times 2100$

=2423.4

i.e. approx 2432 flashes/min