For the pulley system shown in fig. each of the cables at A and B is given a velocity of `2ms^(-1)` in the direction of the arrow. Determine the upward velocity v of the load m.

Options

A. `1.5 ms^(-1)`
B. `3 ms^(-1)`
C. `6 ms^(-1)`
D. `4.5 ms^(-1)`

Answer

A

Explanation

`V_(A)=2ms^(-1)` (towards right )
`:. V_(P_1) = (V_A)/(2) = 1 ms^(-1)` (upwards)
`V_(B)=2ms^(-1)` (towards left)

Now `2V_(P_2)=V_(B)+V_(P_1)`
`:. V_(P_2) = (V_(B)+V_(P_1))/(2) = (2+1)/(2) =1.5ms^(-1)`.