Four person K,L,M and N are initally at the corners of a square of side of length d. If every person starts moving, such that K always heads towards L, L heads towards M, M heads directly towards N and N heads towards K, then the four perons will meet after

Answer

D

Explanation

The relative velocity of `K` w.r.t `L` along the line `KL` is `vec(v)_(KL) = vec(v)_(K) - vec(v)_(L) = vec(v)_(K)+(-vec(v)_(L))`
` = v`
(`because` the component of velocity of `L ` along `KL` is zero )
The displacement of `K` till `K` and `L` meet is `d`.
`:.` Time taken for `K` and `L` to meet will be `= (d)/(v)`