Solving Pulley and Platform Homework w/ Acceleration

  • Thread starter Thread starter judas_priest
  • Start date Start date
  • Tags Tags
    Platform Pulley
Click For Summary
SUMMARY

The discussion focuses on solving a physics problem involving two construction workers of mass m raising themselves on a platform with mass 0.5m using pulleys. The key forces identified include the weight of the workers, the tension in the ropes, and the normal force from the platform. The final equations derived are 2N - 2F - 2mg = 2Ma for the workers and 2f - 0.5mg - 2N = 0.5Ma for the platform, leading to the acceleration formula a = (4f - 7mg) / 7m when the platform mass is increased to 5m.

PREREQUISITES
  • Understanding of Newton's laws of motion
  • Familiarity with forces such as tension and normal force
  • Basic knowledge of mass and acceleration relationships
  • Ability to set up and solve equations involving multiple forces
NEXT STEPS
  • Study the principles of mechanical advantage in pulley systems
  • Learn how to apply Newton's second law in multi-body systems
  • Explore the concept of tension in ropes and its implications in physics problems
  • Practice solving similar problems involving forces and accelerations in different configurations
USEFUL FOR

Students studying physics, particularly those focusing on mechanics, as well as educators looking for examples of force analysis in pulley systems.

  • #31
lollikey said:
I got it ! the answer is (4f-7mg) / 7m
Good show.
 
Physics news on Phys.org
  • #32
Well, I can't understand why there are 4f and not 2f. I thought it was mechanical advantage but these pulleys are fixed to the ceiling, aren't they? I am obviously missing something.
 
  • #33
Poetria said:
Well, I can't understand why there are 4f and not 2f. I thought it was mechanical advantage but these pulleys are fixed to the ceiling, aren't they? I am obviously missing something.
Draw a line across just below the pulleys. How many ropes cross that line? What is the tension in each?
 
  • Like
Likes   Reactions: Poetria
  • #34
I see. There are four ropes and each of them has tension f.
 
  • #35
Poetria said:
I see. There are four ropes and each of them has tension f.
Right.
 
  • Like
Likes   Reactions: Poetria
  • #36
I got it. Many thanks. :)
 

Similar threads

Mechanics Pulley Platform Problem
  • · Replies 13 ·
Replies
13
Views
4K
Analyzing Forces in a Platform and Pulley System
  • · Replies 5 ·
Replies
5
Views
3K
Newton's Second Law (Pulley Sustem)
  • · Replies 3 ·
Replies
3
Views
2K
Falling mass, additionally accelerated by a rope
  • · Replies 18 ·
Replies
18
Views
1K
Olympiad dynamics problem with 3 masses and a pulley
  • · Replies 17 ·
Replies
17
Views
3K
Problem with pulleys - two fixed and one movable
  • · Replies 22 ·
Replies
22
Views
1K
Solve Pulley Problem: Frustrated After Weeks of Trying
  • · Replies 4 ·
Replies
4
Views
2K
Calculating acceleration of a prism and block connected to a wall through a rope and pulley
  • · Replies 4 ·
Replies
4
Views
868
Wordy Physics on Forces, Pulleys, and Friction
  • · Replies 5 ·
Replies
5
Views
5K
Dynamics question about boy pulling himself up via pulley
  • · Replies 1 ·
Replies
1
Views
6K