How to find mass in an Atwood machine

Click For Summary

Homework Help Overview

The discussion revolves around an Atwood machine problem involving a pumpkin and a weight attached to a frictionless pulley. The original poster presents a scenario where a 5kg weight causes the pumpkin to accelerate downwards at 4.65 m/s², prompting a question about determining the mass of the pumpkin.

Discussion Character

  • Exploratory, Assumption checking, Problem interpretation

Approaches and Questions Raised

  • Participants explore the relationship between the acceleration of the pumpkin and the mass of the weight. Questions arise regarding the implications of the pumpkin's downward acceleration on its mass relative to the 5kg weight. There is also discussion about the forces acting on the pumpkin and the tension in the rope, with participants questioning the equations used to relate these variables.

Discussion Status

The discussion is active, with participants questioning the assumptions made in the original poster's approach and suggesting alternative formulations. There is no explicit consensus, but various interpretations and potential corrections to the equations are being explored.

Contextual Notes

Some participants note the need for clarity regarding the definitions of variables used in the equations, particularly the distinction between the masses of the weight and the pumpkin. The original poster's method appears to be under scrutiny, with suggestions for reevaluation of the formulas applied.

iyanna
Messages
2
Reaction score
0

Homework Statement



A pumpkin and a weight are attached to a frictionless pulley. As the 5kg weight is released, the pumpkin accelerates down at 4.65 m/s^2 to the ground. What is the mass of the pumpkin? [/B]

Homework Equations



How do I find the mass?

The Attempt at a Solution



T=m1g
ma=m2g-T
m=m2g-T/a
m=m2g-49/4.65
m=10.53-m2g
m-10.53=m2g
10.53+5=15.53
m2=1.57kg
 
Physics news on Phys.org
It says the pumpkin accelerates downwards. Does that make it more or less than 5kg?
 
haruspex said:
It says the pumpkin accelerates downwards. Does that make it more or less than 5kg?
More
 
You don't make it clear, but I assume you are using m ( or m1) for the mass of the weight and m2 for the pumpkin.
If T is the tension in the rope, what are the forces acting on the pumpkin? What "F=ma" equation does that give you? Same questions for the weight.
 
I think your formula is off.

Shouldn't it be m2 = (ma + T) / g ?
 
Kamisama said:
I think your formula is off.

Shouldn't it be m2 = (ma + T) / g ?
How is that different from
iyanna said:
ma=m2g-T
?
 

Similar threads

Working out the accelerations in a double Atwood pulley system
  • · Replies 25 ·
Replies
25
Views
3K
How Does Mass Loss Affect Acceleration in Atwood's Machine?
  • · Replies 13 ·
Replies
13
Views
3K
What if check: Am I calculating tension wrong?
  • · Replies 3 ·
Replies
3
Views
2K
Atwood Machine: Find M in Terms of m1 & m2
  • · Replies 3 ·
Replies
3
Views
3K
Atwood machine with variable mass
  • · Replies 7 ·
Replies
7
Views
4K
Accelerating pulleys (3 pulleys and 3 masses)
  • · Replies 5 ·
Replies
5
Views
2K
How Do You Calculate the Second Mass in an Atwood Machine Problem?
  • · Replies 17 ·
Replies
17
Views
9K
How Do Double Pulleys Affect Acceleration and Forces in Homework Problems?
  • · Replies 3 ·
Replies
3
Views
2K
Atwood Machine Tensional Value Problem HELP
  • · Replies 2 ·
Replies
2
Views
9K
Block-pulley system and rotational dynamics
  • · Replies 5 ·
Replies
5
Views
5K