What Is the Minimum Initial Velocity to Roll Up a Carpet?

  • Thread starter Thread starter bobsmith601
  • Start date Start date
  • Tags Tags
    Momentum Physics
AI Thread Summary
The discussion focuses on calculating the minimum initial velocity required to roll up a carpet that is partially cylindrical. Participants suggest that this problem can be approached using conservation of energy principles. Key considerations include determining the initial kinetic and potential energy needed to fully roll the carpet to a stop. The conversation emphasizes understanding the energy transformations involved in the process. Overall, the goal is to establish a formula or method to find the necessary initial speed for the cylindrical part of the carpet.
bobsmith601
Messages
2
Reaction score
0

Homework Statement



Imagine a very long carpet, with a very small thickness of t, width W, length L and density of ρ,
which is partially rolled up to form a cylinder of radius r. Since the carpet is very thin, it can be
assumed that the rolled-up part of the carpet is a perfect cylinder. We decide to roll up the whole
carpet by just kicking the cylindrical part of the carpet with initial velocity v.
What is the minimum initial speed v, required for the cylindrical part to roll the whole carpet?
 
Physics news on Phys.org
welcome to pf!

hi bobsmith601! welcome to pf! :smile:
bobsmith601 said:
What is the minimum initial speed v, required for the cylindrical part to roll the whole carpet?

looks to me like a conservation of energy problem …

what energy is needed to end with the carpet fully rolled at zero speed? :wink:
 
I'm not sure...
 
(just got up :zzz:)

for initial speed v, what are the initial kinetic energy and potential energy?

for final speed 0, what are the final kinetic energy and potential energy? :smile:
 

Thread 'Errors and significant figures'

I multiplied the values first without the error limit. Got 19.38. rounded it off to 2 significant figures since the given data has 2 significant figures. So = 19. For error I used the above formula. It comes out about 1.48. Now my question is. Should I write the answer as 19±1.5 (rounding 1.48 to 2 significant figures) OR should I write it as 19±1. So in short, should the error have same number of significant figures as the mean value or should it have the same number of decimal places as...
View full post »
Thread 'Calculation of Tensile Forces in Piston-Type Water-Lifting Devices at Elevated Locations'

Thread 'Calculation of Tensile Forces in Piston-Type Water-Lifting Devices at Elevated Locations'

Figure 1 Overall Structure Diagram Figure 2: Top view of the piston when it is cylindrical A circular opening is created at a height of 5 meters above the water surface. Inside this opening is a sleeve-type piston with a cross-sectional area of 1 square meter. The piston is pulled to the right at a constant speed. The pulling force is（Figure 2）： F = ρshg = 1000 × 1 × 5 × 10 = 50,000 N. Figure 3: Modifying the structure to incorporate a fixed internal piston When I modify the piston...
View full post »
Thread 'A cylinder connected to a hanging mass'

Thread 'A cylinder connected to a hanging mass'

Let's declare that for the cylinder, mass = M = 10 kg Radius = R = 4 m For the wall and the floor, Friction coeff = ##\mu## = 0.5 For the hanging mass, mass = m = 11 kg First, we divide the force according to their respective plane (x and y thing, correct me if I'm wrong) and according to which, cylinder or the hanging mass, they're working on. Force on the hanging mass $$mg - T = ma$$ Force(Cylinder) on y $$N_f + f_w - Mg = 0$$ Force(Cylinder) on x $$T + f_f - N_w = Ma$$ There's also...
View full post »

Similar threads

Question About Momentum: Ball Rolling up a Curved Ramp
Replies
12
Views
1K
How Does the Velocity of a Carpet's Axis Change as It Unrolls?
Replies
3
Views
2K
Speed of cylinder rolling along a horizontal surface gathering snow (Solved)
Replies
13
Views
2K
Horizontal impulse on a ball at rest on a plane (with friction)
Replies
14
Views
3K
Momentum -- pure rolling and trajectory physics problem
2
Replies
63
Views
6K
Why is the work done by gravity not equal to the -ΔGPE? (unrolling carpet)
Replies
21
Views
3K
How to Determine Angular Velocity of a Rolling Sphere on an Inclined Plane?
Replies
11
Views
3K
Impulse Problem -- A rolling cylinder collides with a cylinder at rest
Replies
26
Views
5K
Hoop rolling down incline
Replies
1
Views
3K
What Is the Minimum Velocity Required for a Sphere to Overcome a Step?
Replies
8
Views
5K

Hot Threads

Recent Insights

Back
Top