Question

Two mirrors, mounted vertically, are made to move towards each other with a speed v m/s each. A particle that can bounce back between the two mirrors starts from one mirror when the mirrors are d meters apart. On reaching the second mirror, it bounces back and so on. If the particle keeps on travelling at a constant speed of 4v m/s, how many trips can it make before the mirrors run into each other and what total distance does it cover​

Answer 1

Answer:

Time required for mirrors to run into each other t = d/2v In time t particle will move distance s = 4v × d/2v = 2d Particle will make trips till the distance between two mirrors become 0 So the particle will make infinite number of trips before the two mirrors meet each other

HOPE YOU GET THE ANSWER L-LAWLIT

Answer 2

Answer:

Option 2

Explanation:

Among the four options given in question statement, the correct option is the second one.

Speed at which mirrors are moving v. Since the both move so relative speed would become 2v

The distance between the mirrors is d

Now the particle is moving at a constant speed of 4v, meaning that it is moving twice faster that the mirrors and in one complete cycle, it will cover a distance of 2d.

Hence the particle will make infinite number of trips before the two mirrors meet each other