Pulleys Flashcards
To balance a rod with two equal weights on either end, where must the point of balance be?
The point of balance must be exactly in the middle of the rod.
What are the two rules for finger balances?
1) When the weights are equal, we put our finger in the middle because the average position of mass is in the middle.
2) When the weights are unequal, we move our finger closer to the heavyweight because the average position of mass is closer to the heavyweight.
What is the center of mass (COM)?
The average position of weight
What happens if the center of mass (COM) is directly under the wire support?
The rod will stay flat.
We can rotate a rod around its center of mass without…
changing where it is located.
What describes the force that the rope uses to pull?
It pulls with the same force everywhere along its length.
What are two reasonable approximations to make when working with pulleys?
1) Ropes and pulleys have no mass.
2) Pulleys rotate without any resistance or friction.
