Back to Directory
NEET PHYSICSEasy

Two trains, each 50 m50 \text{ m} long, are travelling in the opposite direction with velocities 10 m/s10 \text{ m/s} and 15 m/s15 \text{ m/s}. The time of crossing is:

A

10 sec

B

4 sec

C

2√3 sec

D

4√3 sec

Step-by-Step Solution

  1. Concept - Relative Velocity: When two objects move in opposite directions, their relative velocity is the sum of their individual speeds.
  • vrelative=v1+v2=10+15=25 m/sv_{relative} = v_1 + v_2 = 10 + 15 = 25 \text{ m/s} .
  1. Total Distance: To cross each other completely, the total distance covered is the sum of the lengths of both trains.
  • d=L1+L2=50+50=100 md = L_1 + L_2 = 50 + 50 = 100 \text{ m}.
  1. Calculate Time: Time taken to cross is given by distance divided by relative speed.
  • t=dvrelative=10025=4 sect = \frac{d}{v_{relative}} = \frac{100}{25} = 4 \text{ sec}.
Practice Mode Available

Master this Topic on Sushrut

Join thousands of students and practice with AI-generated mock tests.

Get Started