Q. An observer A sees an asteroid with a radioactive element moving by at a speed =0.3c and measure the radioactivity decay time to be$T_{A}$. Another observer B is moving with the asteroid and measures its decay time as $T_{B}.$ Then $T_{A}$and $T_{B}$ are released as
A) $T_{B} < T_{A}$
B) $T_{A} = T_{B}$
C) $T_{B} > T_{A}$
D) Either (A) or (c) depending on whether the asteroid is approaching or moving away from A
Explanation
(a) Observers in different inertial frames always measure different time intervals between a pair of events.
According to time dilation
$T_{A} > T_{B}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.