Q. Two trains each $50\ m\ $long are travelling in opposite direction with velocity $10\ m/s$ and $15\ m/s$. The time of crossing is
A) $2s$
B) $4s$
C) $2\sqrt{3}s$
D) $4\sqrt{3\ }s$
Explanation
(b) $Time = \frac{Total\ length\ }{Relative\ velocity} = \frac{50 + 50}{10 + 15} = \frac{100}{25} = 4\sec\ $
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.