Does Mass Affect Friction in a Pulley System?

In summary, the force of friction in a pulley system where a puck is connected to a massless pulley and a hanging mass m on the end of a table would change as the mass of the puck increases. This is because the frictional force is self-adjusting and dependent on the mass of the puck, with the maximum mass of the puck being the point of equilibrium. However, if the mass of the puck exceeds the mass of the block, there will be a net acceleration and the friction force will be different. If the mass of the block is constant and the mass of the hanger gradually increases, the friction force will also increase until reaching the point of limiting friction.
  • #1
tnutty
326
1
Imagine a pulley system, where a puck is connected by a massless string to a massless pulley that joins a mass m that's hanging at the end of the table.

Would the force of friction change as you increase mass m , the object that's hanging? why so?
 
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  • #2
tnutty said:
Imagine a pulley system, where a puck is connected by a massless string to a massless pulley that joins a mass m that's hanging at the end of the table.

Would the force of friction change as you increase mass m , the object that's hanging? why so?

Didn't quite understand what you meant by mass m 'hanging' at the end of the table.
Is it something like this?

th_untitled4.jpg


The mass m on the table and the puck hanging?
 
  • #3
Or is it just the other way, the puck on the table and the mass hanging?
 
  • #4
exactly. So I have a question. Would the force of friction increase as the block that's on the table, mass increases?
 
  • #5
tnutty said:
exactly. So I have a question. Would the force of friction increase as the block that's on the table, mass increases?
That depends on the mass of the puck. We're talking about static friction here, which is a self-adjusting force. The frictional force acting on the block depends on mass of the puck.
 
  • #6
If the mass of the puck was gradually increasing, then what would happen to the friction.
 
  • #7
Its like this. You go on increasing the mass of the puck. the weight of the puck increases accordingly. The friction between the block adjusts itself to a value that equals the weight of the puck UNTIL the point of limiting friction (max. value of static friction). The mass of the puck at this point is the greatest mass it can have for the system to be in equilibrium. If you increase the mass of the puck slightly, there is a net acceleration.
Let the mass of block and puck be M and m
Writing equations, mg - T = 0 and T - f =0 (If you consider the acceleration of both the bodies to be zero)
We get, mg = f.
Mass of the puck is proportional to the frictional force on the block. Hope this makes things clear..
 
  • #8
So what if the mass of the hanger was constant and the mass of the block was constantly increasing, what would happen to friction?

would it stay constant because the tension that the rope is providing is constant.
 
  • #9
tnutty said:
So what if the mass of the hanger was constant and the mass of the block was constantly increasing, what would happen to friction?

would it stay constant because the tension that the rope is providing is constant.

Yea, exactly. You can go on increasing the mass of the block but the friction force remains constant.
 
  • #10
All this, provided..the mass of the puck < mass of the block. Unless, this condition is satisfied there will be a net acceleration and friction will be different.
 
  • #11
and if the block had a constant mass and the hanger had a gradually increasing mass the force of friction would increase up until a point?
 
  • #12
tnutty said:
and if the block had a constant mass and the hanger had a gradually increasing mass the force of friction would increase up until a point?

Yes, it would increase till limiting friction is experienced by the block. Further increase would lead to the block accelerating to the right.
 
  • #13
thanks for making it clear
 

FAQ: Does Mass Affect Friction in a Pulley System?

What is friction?

Friction is a force that opposes the motion of objects as they slide against each other. It is caused by the roughness of the surfaces in contact and the interlocking of the microscopic bumps and ridges on the surfaces.

How does friction affect movement?

Friction slows down or stops the movement of objects. It also requires more force to overcome friction and maintain motion.

What factors affect the amount of friction?

The amount of friction depends on the roughness of the surfaces in contact, the amount of force pushing the objects together, and the types of materials involved.

Can friction be reduced?

Yes, friction can be reduced by using lubricants, such as oil or grease, to create a smoother surface between two objects. Also, using wheels or rollers can reduce friction by changing the type of motion from sliding to rolling.

How is friction beneficial?

Friction has many practical applications, such as creating traction for walking and driving, allowing us to write with a pen or pencil, and slowing down objects to prevent accidents. It also helps to hold objects in place, such as nails in wood or shoes on the ground.

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