A system is shown in the figure. A man standing on the block is pulling the rope. Velocity of the point of string in contact with the hand of the man is `2 m//s` downwards. The velocity of the block will be [assume that the block does not rotate]

Options

A. `3m//s`
B. `2m//s`
C. `1//2m//s`
D. `1m//s`

Explanation

`l_(1)+l_(2)+l_(3)=C`

`(dl_(1))/(dt)+(dl_(2))/(dt)+(dl_(3))/(dt)+(dl_(4))/(dt)=0`
`-v-v+0+v+2=0`
`v=2 m//s`