The mechanical advanteage of a two movable pulley and two fixed pulleys is 4.
Movable PULLEYS: it is the # of ropes supporting the load Block and Tackle PULLEYS: it is the # of ropes supporting the load fixed PULLEYS: MA=1
The IMA (ideal mechanical advantage, conceptually similar to mechanical advantage) of any fixed pulley is equal to the number of axels used by the pulley.
a fixed pulley can only be used for leverage whereas a single movable pulley can be used for both leverage and the mobility of that object giving it one more mechanical advantage.
Movable and fixed.
Fixed pulleys have their center point fixed. i.e. they can only have rotary motion and no linear movement. Movable pulleys do not have their center point fixed, and are free to have translatory as well as rotary motion
A compound pulley
A fixed pulley is different from a movable pulley because a movable pulley has one end of the rope attached to it fixed on an unmoving object. The pulley is free to move with the rope. You pull the other end of the rope. Also, a movable pulley multiplies the applied force (effort force) and therefore has more mechanical advantage. A fixed pulley is attached to something that doesn't move, while one end of the rope is holding the weight, while the other is for pulling.A fixed pulley confers no mechanical advantage, but will convert motion in one direction into another direction.A movable pulley system, if the pulleys change their distance from each other, will confer a mechanical advantage.
Block and tackle (:
fixed and movable pulleys can be combined.
Two kinds of pulleys are the fixed pulley and the movable pulley
movable single multiple fixed inclined
single fixed pulley, single movable pulley and single fixed and movable pulley. :-)