Question

Two toy trains, A and B run towards each other on a conveyor belt of length 2500m The speed of train A is 35 m/s and speed of train B is 15 m/s
What is the time taken by trains to collide, if the speed of the conveyor belt is 10 m/s?​

Answer 1

Given:

Length of conveyor belt=$2500m$

Speed of train A= $35m/s$

Speed of train B= $15m/s$

Speed of belt= $10m/s$

Both the trains run towards each other.

To Find:

Time taken by the trains for the collision.

Solution:

1. Train A moves in the direction of the belt:

Resultant Speed of train A= Speed of train A+ Speed of belt

                                           = $35+10$

                                           =$45m/s$

Resultant speed of train B= Speed of train B-Speed of belt

                                           =$15-10$

                                           =$5m/s$

Time for collision = $\frac{Distance}{Relative Speed of A and B}$

                             =$\frac{2500}{45+5}$

                             =50sec

2. Train B moves in the direction of the belt:

Resultant Speed of train A= Speed of train A- Speed of belt

                                           =$35-10$

                                           =$25m/s$

Resultant speed of train B= Speed of train B+Speed of belt

                                           =$15+10$

                                           =$25m/s$

Time for collision = $\frac{Distance}{Relative Speed of A and B}$

                             =$\frac{2500}{25+25}$

                             =50sec

Hence in both the cases time for collision is 50sec.