A meter stick `AB` of length 1 meter rests on a frictionless floor in horizontal position with end `A` attached to the string as shown. Assume that string connecting meter stick with pulley always remains vertical.

Minimum magnitude of relative velocity of `A` with respect to `B` during the motino specified in question 5 is `:`

Options

A. `2m//s`
B. `4m//s`
C. `6m//s`
D. none of these

Answer

B

Explanation

`vec(v)_(A)=4hat(j) m//s` and `vec(v)_(B)=(-4tanthetahat(i))m//s`
`:. vec(v)_(AB)=(4 tan thetahat(i)+4hat(j))m//s`
`:. v_(AB)=4sqrt(1+tan ^(2)tan)=(4)/(cos theta)`
`:. (v_(AB))_(mi n)=4m//s`