Three particles starts from origin at the same time with a velocity `2 ms^-1` along positive x-axis, the second with a velocity `6 ms^-1` along negative y-axis, Find the velocity of the third particle along `x = y` line so that the three particles may always lie in a straight line.

Options

A. `-3sqrt(3)`
B. `3sqrt(2)`
C. `-3sqrt(2)`
D. `2sqrt(2)`

Answer

B

Explanation

Let the third particle be at point C at time t and has velocity V from figure
`(Vt)/sintheta =(6t)/sin(45-theta)also tantheta =(2t)/(6t)=1/3`
`on solving V=3sqrt(2)m//sec (B)is correct]`