Pulley system -- Calculate the mass that balances this pulley system

Click For Summary
SUMMARY

The discussion focuses on calculating the mass that balances a pulley system, specifically addressing the forces involved and the importance of free body diagrams. The force exerted by mass A is calculated as FA = sin(25°) * 50 * 9.82, resulting in 208.5 N. Participants emphasize the need to understand tension in the rope, noting that it may vary and should be symbolically represented before substituting numerical values. The advice to work symbolically helps streamline calculations and avoid unnecessary arithmetic.

PREREQUISITES
  • Understanding of basic physics concepts, particularly forces and tension.
  • Familiarity with free body diagrams and their application in mechanics.
  • Knowledge of trigonometric functions, specifically sine, in force calculations.
  • Ability to manipulate algebraic expressions symbolically before numerical evaluation.
NEXT STEPS
  • Study the principles of free body diagrams in physics.
  • Learn about tension in ropes and how it varies in different pulley configurations.
  • Explore trigonometric functions and their applications in physics problems.
  • Practice solving problems symbolically to enhance calculation efficiency.
USEFUL FOR

Students studying physics, particularly those focusing on mechanics, as well as educators and anyone interested in mastering pulley systems and force analysis.

FFTB
Messages
1
Reaction score
0
Homework Statement
Calculate the mass of mB that makes the system to be in equilibrium. Neglect the possible friction
Relevant Equations
Sin cos tan
pulley.png

I've been stuck at this pulley system for a while.
I've calculated the force of which A pulls => FA = sin25*50*9.82 = 208.5 N
But I get stuck on the free body diagram.
Can someone help and explain the freebody diagram
uträkning.png
 

Attachments

  • pulley.png
    pulley.png
    4.3 KB · Views: 161
Physics news on Phys.org
Let T be the tension in the rope. Does it vary along the rope? What is the tension force on mass A? On mass B?
 
Your work looks ok except for ##m_B=T##. What have you missed out?
As a matter of style, learn to work entirely symbolically, only plugging in numbers at the end. It has many advantages.
In the present case, you could have avoided some arithmetic since g would cancel.
 

Similar threads

  • · Replies 5 ·
Replies
5
Views
1K
  • · Replies 22 ·
Replies
22
Views
6K
  • · Replies 30 ·
2
Replies
30
Views
4K
  • · Replies 8 ·
Replies
8
Views
3K
  • · Replies 13 ·
Replies
13
Views
7K
  • · Replies 1 ·
Replies
1
Views
2K
Replies
4
Views
2K
  • · Replies 11 ·
Replies
11
Views
2K
Replies
24
Views
4K
  • · Replies 40 ·
2
Replies
40
Views
6K