How Much Force is Needed to Keep a Drilled Cylinder at Rest?

  • Thread starter Thread starter physicsboy121
  • Start date Start date
  • Tags Tags
    Cylinder Hole
Click For Summary

Homework Help Overview

The problem involves a uniform cylinder with a drilled hole, requiring the calculation of the horizontal force needed to keep it at rest. The subject area includes concepts of torque, center of mass, and static equilibrium.

Discussion Character

  • Exploratory, Assumption checking, Conceptual clarification

Approaches and Questions Raised

  • Participants discuss the need to determine the center of mass for the modified cylinder and explore different conceptualizations of the problem, including treating the drilled hole as a negative mass or considering symmetrical drilling.

Discussion Status

Some participants have offered alternative perspectives on how to approach the problem, suggesting different ways to visualize the mass distribution and torque calculations. There is an indication of productive dialogue, but no explicit consensus has been reached.

Contextual Notes

Participants note the importance of understanding the center of mass and the implications of torque in the context of static equilibrium. There may be constraints related to the assumptions about mass distribution and the geometry of the cylinder.

physicsboy121
Messages
6
Reaction score
0

Homework Statement


A uniform cylinder of radius R and mass 8kg has an off-axis hole drilled through it at 2R/5. Its new mass is 6.5kg. The hole and cylinder are parallel with their centers being the same height. What horizontal force, F, must be applied on the top to keep the cylinder at rest?


Homework Equations


I tried writing a torque equation for static equilibrium. However, I need to know the center of mass for the cylinder with the drilled hole, but I do not know it. Is there a better approach to this problem?


The Attempt at a Solution


Torque_net = (6.5)(distance of center of mass from cylinder's center) - (F)(R)=0
 
Physics news on Phys.org
Just think it is a solid cylinder plus a thin cylinder of negative mass.
 
Or you can imagine another hole, drilled symmetrically to the first, with the same mass taken out. The remaining cylinder will have 5 kg at x=0, one hole is actually filled with mass 1.5 kg at 2R/5. Then it shall be easy to calculate new xcom in terms of R.
Also g shall be involved in the torque calculation..
 
I got it, thanks so much!
 

Similar threads

A cylinder connected to a hanging mass
  • · Replies 21 ·
Replies
21
Views
2K
A slanted cylinder full of liquid about to fall
  • · Replies 12 ·
Replies
12
Views
2K
Sinking a cylinder with varying hole sizes
  • · Replies 97 ·
4
Replies
97
Views
15K
Cylinder rolling on a moving board
  • · Replies 16 ·
Replies
16
Views
3K
Choosing Axis of Rotation in Cylinder Oscillation Problem
  • · Replies 1 ·
Replies
1
Views
2K
Cylinder Equilibrium (2012 F = ma #12)
  • · Replies 6 ·
Replies
6
Views
3K
Cylinder balancing in a single plane and in two planes
  • · Replies 1 ·
Replies
1
Views
1K
What is the magnitude of the acceleration of cylinder's com?
  • · Replies 4 ·
Replies
4
Views
2K
Maximum torque on a rotating cylinder kept on a moving plank
  • · Replies 22 ·
Replies
22
Views
3K
Stability of a floating cylinder
  • · Replies 7 ·
Replies
7
Views
3K