There are four dogs/ants/people at four corners of a square
of unit distance. At the same instant all of them start
running with unit speed towards the person on their
clockwise direction and will always run towards that target.
How long does it take for them to meet and where?

Answer Posted / nikhra

They will meet at the center of the square after unit time,
they will travel unit distance.
At any moment of time dogs will be at the corner of another
square with smaller size and same center, size of square
will decrease with time and finally they will meet at
center.
At any moment of time their speed toward center will be
1*cos(45) = 1/√2, and radial distance is √2, so they will
meet after √2/ (1/√2) = 1 unit time and will travel unit
distance.

Is This Answer Correct ?    24 Yes 11 No



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