ideally 1
If the single pulley moved with the target it would be two. However a single pulley attached to the wall gains you nothing but perhaps a better pulling angle. so 0.8 *1 = 0.8
Now if the pulley is on the wall and you sit on top of the pile of bricks on the sled you are pulling, then you get MA = 2, ( the wall pulls on both you and the sled) but you did not say that.
The efficient of a single fixed pulley is 80% find its mechanical advantage
1 answer