Q. A man sets his watch by the sound of a siren placed at a distance $1\ km$ away. If the velocity of sound is $330\ m/s$
A) His watch is set 3 sec. faster
B) His watch is set 3 sec. slower
C) His watch is set correctly
D) None of the above
Explanation
(b) $Time = \frac{Distance}{Velocity} = \frac{1000}{330} = 3.03\ \sec$
Sound will be heard after $3.03\ \sec.$ So his watch is set $3sec,$ slower
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.