# If a pulley system with an ideal mechanical advantage of 2 is used in lifting a 2,000 lb. car, how far would the car move if the effort moved 2 ft.?

Nov 19, 2015

$1 \text{ft}$

#### Explanation:

Since work = force x distance and assuming 100% efficiency we can write:

${F}_{l} \times {D}_{l} = {F}_{e} \times {D}_{e}$

$\therefore {F}_{l} / {F}_{e} \times {D}_{l} = {D}_{e}$

Since $M A = {F}_{l} / {F}_{e} = 2$ we can write:

$2 \times {D}_{l} = {D}_{e} = 2$

$\therefore {D}_{l} = \frac{2}{2} = 1 \text{ft}$