## Question:

Determine the displacement of the block B if A is pulled down 4 ft.

## Step-by-step

2 $s_{A}$+2 $s_{C}$=$l_{1}$
$\Delta$ $s_{A}$=-$\Delta$ $s_{C}$
$s_{B}$$s_{C}$+$s_{B}$=$l_{2}$
2 $\Delta$ $s_{B}$=$\Delta$ $s_{C}$
Thus,
$\Delta$ $s_{B}$=-$\Delta$ $s_{A}$
2 $\Delta$ $s_{B}$=-4
$\Delta$ $s_{B}$=-2 ft=2 ft$\uparrow$