The "Lifting Your Fridge with a Pulley System

Click For Summary
SUMMARY

The discussion focuses on designing a pulley system to lift a fridge weighing 950N using a maximum force of 250N. Participants are tasked with creating a diagram of the pulley system, calculating the distance the rope must be pulled, and determining the work done with and without the pulley system. Key equations include W=F*D for work, and the definitions of Ideal Mechanical Advantage (IMA) and Actual Mechanical Advantage (AMA), which are crucial for understanding the efficiency of the system.

PREREQUISITES
  • Understanding of basic physics concepts such as force, work, and distance.
  • Familiarity with pulley systems and mechanical advantage.
  • Knowledge of the equations for work (W=F*D) and efficiency calculations.
  • Ability to interpret and apply variables in physics equations (e.g., FL, FA, DA, DL).
NEXT STEPS
  • Research how to diagram a simple pulley system for lifting heavy objects.
  • Learn about calculating mechanical advantage in pulley systems.
  • Study the principles of work and energy conservation in physics.
  • Explore practical applications of pulleys in construction and engineering.
USEFUL FOR

Students studying physics, particularly those learning about mechanics and pulley systems, as well as educators seeking to enhance their teaching methods in practical physics applications.

Practice
Messages
2
Reaction score
0

Homework Statement


You wish to put your fridge on the second floor of your house (again).
You decide to rig up a pulley system so as to not overexert yourself.
Your maximum force is 250N and the fridge weighs 950N.

a) diagram a pulley system using the fewest number of pulleys, which can achieve
this feat
b)The fridge must be raised 2.4 m, how far must you pull the rope?
(Hint: you can still calculate this without the diagram)
c) Calculate the work done using the pulley system and the work you
would have done without the pulley system.
d) What is the IMA of the system?

Homework Equations


W=F*D
P= W/t
AMA= FL/FA
IMA= DA/DL
EFFICIENCY= (work done by machine/work done on machine)x 100
or
EFFICIENCY= (AMA/IMA) * 100
 
Physics news on Phys.org
Have you done anything at all? How about applying some of those equations?

What "mechanical advantage" do you need? (In other words, how many times the maximum force you can apply is the weight of the fridge?) Since the total work you do does not change (conservation of energy) over what distance must you apply your maximum force to be equal to the "weight times distance" for the fridge?

Your "relevant equations" are meaningless unless you know what the letters stand. I might guess that "W= FD" is "work", "force" and "distance" but what are "FL", "FA", "DA", and "DL"?
 
wait

I didn't do anything yet because our teacher did not teach us how to do problems with pulleys, or a problem like this in general.
da: distance applied
dl: distance load
fl:force load
fa:force applied.
I just don't know how to start it, if I get a lead on how to do it I think I'll be able to get through it.
 

Similar threads

Pulley system for cardboard pulp shredder/mixer
  • · Replies 7 ·
Replies
7
Views
3K
Increasing the number of pulleys
  • · Replies 1 ·
Replies
1
Views
16K
Length of a string over a 2 pulley system
  • · Replies 7 ·
Replies
7
Views
2K
Why Ignore Tension In Pulley and Work Energy Problems?
  • · Replies 4 ·
Replies
4
Views
2K
How Much Work is Done Raising a Load with a Two-Pulley System?
  • · Replies 2 ·
Replies
2
Views
2K
Pulley System: Calculate Work, Force, Efficiency
  • · Replies 6 ·
Replies
6
Views
2K
Lifting an elephant with a pulley & rope
  • · Replies 7 ·
Replies
7
Views
5K
Model Pulley: Understanding System Physics
  • · Replies 27 ·
Replies
27
Views
10K
Forces with Tension and pulleys
  • · Replies 6 ·
Replies
6
Views
3K
Undergrad Effective Friction Related to Pulley Radius (Atwood Machine)
  • · Replies 4 ·
Replies
4
Views
3K