A pulley with one wheel allows you to reverse the direction of your lifting force by pulling down on a rope (that’s looped over the wheel), lifting your weight. With a two-wheel pulley, you reduce the effort you exert to lift the same amount of weight. You lift the weight with half the force.
Q. What happens if you add a second pulley to a pulley system?
The powerful mechanical advantage of a pulley is in using many pulleys at once. Combining multiple pulleys decreases the amount of force necessary to move an object by increasing the amount of rope used to raise the object.
Table of Contents
- Q. What happens if you add a second pulley to a pulley system?
- Q. How does a single movable pulley work?
- Q. Is there friction in a pulley?
- Q. What happens if a pulley has friction?
- Q. What if a pulley has friction?
- Q. Can a pulley rotate without friction?
- Q. What does a massless pulley mean?
- Q. What if the pulley has mass?
- Q. Is there tension when there is no friction?
Q. How does a single movable pulley work?
The wheel of a moveable pulley is not attached to any stationary object; one end of the rope is stationary instead. In a moveable pulley, the weight is attached to the wheel rather than the rope, and the wheel moves along the length of the rope as the weight is lifted or lowered.
Q. Is there friction in a pulley?
In any system where a belt or a cable is wrapped around a pulley or some other cylindrical surface, we have the potential for friction between the belt or cable and the surface it is in contact with. In some cases, such as a rope over a tree branch being used to lift an object,the friction forces represent a loss.
Q. What happens if a pulley has friction?
This frictional force actually exerts a torque on the pulley and causes its angular acceleration [2]. At the same time, the friction gives rise to a difference in tension between the ends of the string laid on the pulley, even for a massless string [3, 4] . …
Q. What if a pulley has friction?
In absence of this friction, the pulley wouldn’t rotate. The rope would just slip over the pulley and the tension is same throughout the rope. The friction at the axle, on the other hand, opposes the rotation of pulley – a completely opposite effect as compared to that by the friction between rope and pulley.
Q. Can a pulley rotate without friction?
A stationary light, smooth pulley can rotate without friction about a fixed horizontal axis. A light rope passes over the pulley.
Q. What does a massless pulley mean?
The role of the pulley is a system is to change the direction of the tension acting on the pulley. Therefore, to make things simple, we often use the massless and frictionless pulley approximation. If the pulley has a mass “m”, then It has a moment of inertia I which is functiom of mass m.
Q. What if the pulley has mass?
Because the pulley possesses mass, you need to apply a non-zero net torque to it to increase its angular acceleration (assuming that is the goal here). If the tensions were the same on both sides of the contact point between the string and the pulley, there would be no angular acceleration.
Q. Is there tension when there is no friction?
If there is no friction, the tension is transmitted undiminished. Only its direction changes, and it is always parallel to the flexible connector.
