Solving Masses on a Beam Problem with Scales

  • Thread starter Thread starter delecticious
  • Start date Start date
  • Tags Tags
    Beam
Click For Summary

Homework Help Overview

The problem involves a massless beam suspended between two scales, with three different masses hanging from it. The participants are trying to understand how the scales measure the forces exerted by the masses and how to approach the problem using principles of equilibrium.

Discussion Character

  • Exploratory, Conceptual clarification, Mathematical reasoning

Approaches and Questions Raised

  • Participants discuss visualizing the setup of the scales and the masses, questioning how the scales can measure the weights of the masses above them. There is mention of using the center of gravity equation and the conditions for equilibrium, including the sum of forces and torques.

Discussion Status

Some participants have offered guidance on using equilibrium conditions to find the scale readings, while others are exploring the relationship between tensions in the ropes and the weights of the masses. There is an ongoing examination of how to combine these concepts to solve for the tensions.

Contextual Notes

Participants are grappling with the visualization of the problem and the implications of the setup, including the roles of tensions in the ropes connecting the masses to the beam. There is a focus on understanding the relationships between the forces involved without reaching a definitive conclusion.

delecticious
Messages
65
Reaction score
0

Homework Statement


A massless beam is suspended between two scales that are separated by 6.40 m as shown in the diagram below. The scales measure a force in Newtons. Three masses are hanging from the beam: Mass X = 17.7 kg is D1 = 2.11 m from scale A, mass Y = 23.0 kg is D3 = 0.96 m from scale B (hence D2 = 3.33 m), and mass Z = 7.59 kg is hanging directly under scale B. [Use g = 9.81 m/s2.]

prob23a.gif



Homework Equations





The Attempt at a Solution


My main issue with this problem is I'm having trouble visualizing how these scales work, and since I can't visualize I can't even fathom how to approach it. Maybe it's the way the drawing is drawn but I'm not seeing how the three boxes could be weighed by scales above them, how is that even possible? Am I missing something or am I just looking at this entire picture wrong. Can anyone help me see how these scales are supposed to function?
 
Physics news on Phys.org
you know what never mind I think I just realized how I'm supposed to be looking at this. I'm supposed to user the center of gravity equation right? And if I use that how will that help me figure out what each scale reads?
 
Last edited:
The scales just measure the tension in the ropes they are attached to. I assume the problem is to find the scale readings. Use the conditions for equilibrium. (The sum of the forces = 0 & the sum of the torques = 0.)
 
what about the tensions in the ropes connecting the boxes to the beam?
 
delecticious said:
what about the tensions in the ropes connecting the boxes to the beam?
Those tensions just equal the weights of the boxes.
 
so if I denote the one tension as T1 and the other as T2, would I be correct in saying that T1 + T2 = Wx + Wz + Wy ? or are the tensions not equal to each other?
 
delecticious said:
so if I denote the one tension as T1 and the other as T2, would I be correct in saying that T1 + T2 = Wx + Wz + Wy ?
This is correct. Now combine this with a torque equation and you can solve for the tensions.
 

Similar threads

Determining mass of a weight on a three spring scale setup
  • · Replies 14 ·
Replies
14
Views
4K
with this tension problem -- Mass on an accelerating cable
  • · Replies 3 ·
Replies
3
Views
2K
Convert N/m^2 to Newtons, beam problem
  • · Replies 6 ·
Replies
6
Views
2K
Solve Torque Beam Problem: Mass Calculation
  • · Replies 10 ·
Replies
10
Views
5K
Undergrad Apparent Weight problem (falling beam)
  • · Replies 2 ·
Replies
2
Views
2K
How Does Throwing a Medicine Ball Affect Beam Displacement?
  • · Replies 4 ·
Replies
4
Views
6K
Mass submerged in oil and scales problem
  • · Replies 1 ·
Replies
1
Views
9K
Gravity and Mass Homework: 0.000000364kg
  • · Replies 3 ·
Replies
3
Views
2K
Torque problem -- designating center of mass as pivot point
  • · Replies 9 ·
Replies
9
Views
7K
Center of mass with 2 people, a medicine ball, and a beam
  • · Replies 1 ·
Replies
1
Views
4K