Determining reaction forces and angle

Click For Summary

Homework Help Overview

The problem involves determining the mass of box K and the reaction forces at supports G and N in a system of cables and pulleys, with a specific angle requirement for one of the cables. The context is rooted in mechanics, particularly focusing on forces and equilibrium in a static system.

Discussion Character

  • Exploratory, Conceptual clarification, Mathematical reasoning

Approaches and Questions Raised

  • Participants discuss the use of free body diagrams (FBD) to analyze forces acting on the pulleys and boxes. There are attempts to set up equations based on equilibrium conditions, specifically addressing the forces due to gravity and the angles involved. Questions arise about the clarity of the equations and the interpretation of the forces.

Discussion Status

Some participants provide guidance on setting up the free body diagrams and suggest equations to find the mass of box K and the reaction forces. There is an ongoing exchange of clarifications and confirmations regarding the setup of the problem, with no explicit consensus reached yet.

Contextual Notes

The original poster expresses difficulty after converting mass to force, indicating a potential gap in understanding the application of equilibrium conditions. The discussion includes hints and steps without providing direct answers, maintaining a focus on the learning process.

brostingy
Messages
2
Reaction score
0

Homework Statement


An assembly is shown in Figure 1, GH, HK and HNL are three cables. The mass of box L is 350 kg,
a) Determine the mass of box K in order to make angle teta = 30 degrees
b) Determine the reaction forces at supports G and N.


i started by converting the 350kg to a force using F=ma, but stuck there...

help

digram attached to post
 

Attachments

Physics news on Phys.org
First, do FBD of the pulley that K is on.

\SigmaFy=0=mLgsin30-mkg

That solves mk.

Reaction at G is x-component of the above FBD Gx = mLgcos30.

I'm sure you can figure out Rn now.

Hope that helps.
 
ye thanks, i think i follow you, but just to clarify,

FDB is:

mass of L x gravity x sin30 - mass of K x gravity = 0

reaction at G:

G = mass of L x gravity x cos30

Rn:

should be:

y + x values...

sorry to sound dumb... :(
 
I won't give you the answers, but I'll give you the steps.

  1. Draw FBD of Pulley K
  2. Solve for x and y components to find mass of k and Rg. HINT: the magnitude (or hypotenuse) of the rope that's on 30 deg is the transferred weight of L
  3. Draw FBD of Pulley L. You need a reaction force going up for Rn, and two forces (one on an angle of 30 deg-Also, remember 3rd Law) caused by the weight of Box L.
  4. Split this diagram into x and y components and solve for Rnx and Rny, because the rest is know.

Do that make sense? Let me know what you get.
 

Similar threads

  • · Replies 7 ·
Replies
7
Views
7K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 1 ·
Replies
1
Views
3K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
Replies
1
Views
4K
Replies
8
Views
2K
  • · Replies 1 ·
Replies
1
Views
10K
Replies
5
Views
1K
  • · Replies 2 ·
Replies
2
Views
1K