Lifting/breaking an object with circular motion

[great_scott]

i have two questions i think are asking almost the same thing.

1) in this typical centripetal force experiment; there are a stopper mass attacthed to one end of a rope and a washer attached to the other end of the rope. as the washer hangs straight down, i start whirling the stopper. after a point, the faster i whirl it, the more the washer goes up. the question is what is the force that pulls the washer upwards? i assume the tension must always be equal to the centripetal force that is created by the weight of the washer so it shouldn't be enough to beat the weight of the washer to lift it.

2)there is a nut or something breakable on an end of a rod and as you whirl the rod vertically keeping the nut in a circular motion. as you do it faster and faster you observe the nut breaks or at least gets damage soon or later. what is the force that breaks the nut?

thanks.

 

[Doc Al]

the question is what is the force that pulls the washer upwards?

The string tension.

i assume the tension must always be equal to the centripetal force that is created by the weight of the washer so it shouldn't be enough to beat the weight of the washer to lift it.

Don't assume that the tension just equals the weight of the washer. By spinning the stopper faster, you create more tension, which raises the washer.

2)there is a nut or something breakable on an end of a rod and as you whirl the rod vertically keeping the nut in a circular motion. as you do it faster and faster you observe the nut breaks or at least gets damage soon or later. what is the force that breaks the nut?

The faster you whirl the rod, the greater force it must exert on whatever is attached to it. Eventually, something breaks.

 

[great_scott]

how do i creat more tension with no additional force? and obviously as the washer goes up it gains some more potential energy so there has got to be a net force that does some work against gravity by raising the washer?
i can actually put it that way what force makes the rope break when i whirl an object attachted to the rope fast enough? let's say vertically and above my head.

 

[Doc Al]

how do i creat more tension with no additional force? and obviously as the washer goes up it gains some more potential energy so there has got to be a net force that does some work against gravity by raising the washer?

Tell me how you get the stopper to go faster.

i can actually put it that way what force makes the rope break when i whirl an object attachted to the rope fast enough? let's say vertically and above my head.

When the string tension gets too high, the string breaks. You are pulling on the string with a greater force as you twirl it faster.

 

[PJC01]

I can provide an explanation for both of these scenarios using the principles of circular motion and forces. In the first scenario, the force that pulls the washer upwards is the centripetal force. This is the force that is directed towards the center of the circular motion and keeps the washer moving in a circular path. This force is provided by the tension in the rope, which is always equal to the centripetal force. As you increase the speed of the stopper, the centripetal force also increases, causing the washer to move further away from the center and appear to be "lifting" upwards.

In the second scenario, the force that breaks the nut is the centripetal force as well. As the rod is whirled faster and faster, the centripetal force acting on the nut also increases. If this force becomes greater than the breaking strength of the nut, it will break or get damaged. This is because the nut is not able to withstand the force pulling it towards the center of the circular motion.

In both cases, the centripetal force is the key factor in lifting or breaking the objects. It is important to note that the centripetal force is not a separate force, but rather the result of the combination of other forces, such as tension in the rope or the rotating motion of the rod. Understanding these forces and their effects on objects in circular motion is crucial in many scientific fields, such as physics and engineering.