A question on double-pulley

  • Thread starter lmlgrey
  • Start date
In summary, for the modified Atwood machine with no friction and only gravity as the force, the two masses (m1 and m2) are rigidly attached to the pulleys and connected by a massless string. The total force acting on m1 and m2 is zero and in the same direction, with equal magnitudes. However, since it is unknown whether the pulleys are in motion or not, the tension force may vary. For mass m1, there are two tension forces pulling up and the weight of m1 pulling down, while for mass m2, there is only one tension force and its weight pulling down.
  • #1
lmlgrey
18
0
1. For the modified Atwood machine of this problem, assume that the two masses do move. Also assume that there is no friction, and that gravity is the only force acting. Also assume that you can ignore the mass of the pulleys and of the connecting rod and string. Notice that mass m1 is rigidly attached to the smaller pulley.
Do this problem in 3 stages, by answering the following questions.

1. The total force acting on mass m1 and that acting on mass m2 areboth zero TF
2. in the same direction TF
3. equal in magnitude TFhttp://b.imagehost.org/0304/lerner3_53.gif [Broken]
[/URL]






3. my guess is that since the tension force is the same everywhere on this massless string, then the total force acting on mass m1 and m2 should be both zero... but its known whether the pulleys are in motion or not so...
 
Last edited by a moderator:
Physics news on Phys.org
  • #2
Look 2 chords are pulling up on the mass m1 and only one on the mass m2

So for mass m1 it becomes 2T up and m1g down and for other T up and m2g down
 
  • #3


Your guess is partially correct. In this problem, the total force acting on mass m1 and m2 is not zero, but it is equal in magnitude and in the same direction. This is because in an Atwood machine, the two masses are connected by a massless string, which means that the tension force is the same throughout the string. Since there is no friction and gravity is the only force acting, the two masses will move in the same direction with equal acceleration. Therefore, the total force acting on each mass will be equal in magnitude and in the same direction.
 

1. What is a double-pulley?

A double-pulley is a type of pulley system that consists of two pulleys connected together by a belt or rope. It allows for a change in direction of force and can also amplify the force applied.

2. How does a double-pulley work?

A double-pulley works by distributing the force applied to the rope or belt between the two pulleys. The first pulley redirects the force, while the second pulley amplifies it. This allows for a more efficient transfer of energy.

3. What are the advantages of using a double-pulley?

The main advantage of using a double-pulley is that it can reduce the amount of force needed to lift or move an object. It also allows for a change in direction of force, making it useful in a variety of situations.

4. Can a double-pulley system be used for heavy loads?

Yes, a double-pulley system can be used for heavy loads as it allows for the force to be distributed between two pulleys, making it easier to lift or move heavier objects.

5. How do you calculate the mechanical advantage of a double-pulley system?

The mechanical advantage of a double-pulley system can be calculated by dividing the output force by the input force. In the case of a double-pulley, this would be the weight being lifted divided by the force applied to the rope or belt.

Similar threads

  • Introductory Physics Homework Help
Replies
3
Views
705
  • Introductory Physics Homework Help
Replies
17
Views
1K
  • Introductory Physics Homework Help
Replies
15
Views
2K
  • Introductory Physics Homework Help
Replies
14
Views
859
  • Introductory Physics Homework Help
Replies
10
Views
3K
  • Introductory Physics Homework Help
Replies
5
Views
1K
  • Introductory Physics Homework Help
Replies
2
Views
793
Replies
25
Views
2K
  • Introductory Physics Homework Help
Replies
18
Views
1K
  • Introductory Physics Homework Help
Replies
10
Views
2K
Back
Top