Solving the Mystery of Wrench Work Ratios

Click For Summary

Homework Help Overview

The discussion revolves around the work done by different lengths of wrenches when applying torque to tighten a nut. The original poster attempts to understand the relationship between the length of the wrench and the work done, particularly questioning the relevance of the radius of the nut provided in the problem statement.

Discussion Character

  • Exploratory, Assumption checking

Approaches and Questions Raised

  • Participants explore the torque produced by different lengths of wrenches and question how the radius of the nut factors into the calculations. There is a discussion about the forces required to tighten the nut with varying wrench lengths.

Discussion Status

Participants are engaging in a back-and-forth exploration of the problem, with some suggesting that the force required with a longer wrench may be half that of a shorter one. However, there is no explicit consensus on the implications of this finding or the overall ratio of work done.

Contextual Notes

There is uncertainty regarding the use of the radius of the nut in the calculations, and the original poster expresses confusion about its relevance. The discussion reflects an ongoing attempt to clarify these points without arriving at a definitive conclusion.

Saitama
Messages
4,244
Reaction score
93

Homework Statement


(see attachment)

Homework Equations


The Attempt at a Solution


If a force a F acts on the farther end of the wrench, the torque due to it Fl where l is the length of wrench. The work done by this torque for one full turn is Fl*(2##\pi##)
For wrench A, l=10 cm, and for wrench B, l=20cm.
Therefore the ratio of work done is 0.5. But this is wrong. :confused:
I don't understand why they have given the radius of the nut. I haven't used this information and I have no idea about where to use this.

Any help is appreciated. Thanks!
 

Attachments

  • wrench and nut.png
    wrench and nut.png
    36.8 KB · Views: 450
Physics news on Phys.org
If a force F is required to tighten the nut using the 10 cm wrench, what force is required with the 20 cm one?
 
F/2?
 
Pranav-Arora said:
F/2?
Right.
 
Doc Al said:
Right.

But what next? Does that mean the ratio is 1?
 
Pranav-Arora said:
But what next? Does that mean the ratio is 1?
That's what I would say.
 
Doc Al said:
That's what I would say.

Thanks a lot Doc Al! :smile:
 

Similar threads

Finding the Force on a bolt from a wrench
  • · Replies 7 ·
Replies
7
Views
3K
How Do You Calculate Torque on a Wrench?
  • · Replies 4 ·
Replies
4
Views
4K
Specified Torque Specs on Automotive Fasteners -- Required or just suggestions?
  • · Replies 13 ·
Replies
13
Views
5K
Frequency & Wavelength of a Vibrating Wire
  • · Replies 5 ·
Replies
5
Views
2K
Ratio of Inductance between 2 Solenoids?
  • · Replies 3 ·
Replies
3
Views
4K
Friction and Rotation: Understanding the Ratio of Forces on a Rotating Disk
  • · Replies 5 ·
Replies
5
Views
1K
Help Calculating probability between 2 limits for the ground state
  • · Replies 28 ·
Replies
28
Views
2K
Minimum Shear Stress in Hollow Circular Tube
  • · Replies 3 ·
Replies
3
Views
14K
How Do Forces Distribute on a Board Supported at Two Points?
  • · Replies 6 ·
Replies
6
Views
2K
Problem involving space elevators
  • · Replies 19 ·
Replies
19
Views
2K