A moveable pulley does provide mechanical advantage. With a moveable pulley, one end of the rope is tied to something stable and the pulley and the load both move. There are many times when a fixed pulley is used to anchor a moveable pulley. Fixed and moveable pulleys are used together to move very heavy loads, such as pianos. An example of a moveable pulley is a block and tackle that is used to remove engines from cars. Next time you go to a car mechanic shop with your parents, take note of the pulley system that is used to lift engines out of cars.
