I believe by "balanced" they mean that the net force is zero.Seneka said:
Note how the cable attaches to the weight. When the weight moves down by 1 unit, how much cable must move through the pulley above the car? (You might want to play around with a piece of string to better visualize what happens.)Seneka said:
A pulley system is a simple machine that consists of a wheel with a groove around its circumference and a rope or belt that runs around the groove. The rope or belt is used to lift or move objects by applying force to one end of the rope and pulling it through the pulley. The pulley system works by distributing the weight of the object being lifted across multiple ropes or belts, making it easier to lift the object.
There are three main types of pulley systems: fixed, movable, and combined. In a fixed pulley system, the pulley is attached to a stationary object and only changes the direction of the force applied. In a movable pulley system, the pulley is attached to the object being lifted, reducing the amount of force needed to lift the object. A combined pulley system is a combination of fixed and movable pulleys, which allows for both a change in direction and a reduction in force.
The mechanical advantage of a pulley system is calculated by dividing the output force (the weight of the object being lifted) by the input force (the force applied to the rope or belt). For a fixed pulley system, the mechanical advantage is equal to 1. For a movable pulley system, the mechanical advantage is equal to the number of ropes or belts supporting the object. For a combined pulley system, the mechanical advantage can be calculated by multiplying the mechanical advantages of each individual pulley in the system.
Ideal mechanical advantage refers to the calculated mechanical advantage of a pulley system, assuming that there is no friction or energy loss in the system. Actual mechanical advantage takes into account the effects of friction and energy loss, which can decrease the efficiency of the pulley system and result in a lower mechanical advantage.
Yes, a pulley system can be used to lift objects heavier than the input force. This is possible because the weight of the object is distributed across multiple ropes or belts, reducing the force needed to lift the object. However, the mechanical advantage of the pulley system will decrease as the weight of the object increases, and there will still be some amount of force required to lift the object.
