Newton's Laws Applications - Systems

Click For Summary

Homework Help Overview

The discussion revolves around the application of Newton's Laws in a physics context, specifically focusing on problems involving tension, acceleration, and forces in a system of masses. Participants are preparing for a quiz based on handouts provided by their professor, which include multiple problems requiring calculations.

Discussion Character

  • Exploratory, Conceptual clarification, Mathematical reasoning

Approaches and Questions Raised

  • Participants discuss the relationships between tension and acceleration in a system of masses, questioning how these quantities interact. They express a need for examples to understand the equations governing these relationships.

Discussion Status

Some participants have provided insights into the nature of the problems, including the types of forces to consider (normal force, tension, and acceleration). There is an ongoing exploration of how to derive equations from free-body diagrams, with some attempts to clarify the relationships between different variables.

Contextual Notes

Participants are working under the constraint of limited guidance from their professor and are seeking to understand the material better before an upcoming quiz. They mention specific types of forces and conditions (e.g., kinetic friction) that will be relevant to their problems.

BillTheButcher
Messages
4
Reaction score
0
Hello,

I am taking intro Physics and we are having a little quiz this friday. Professor gave us handouts and told us to solve them by ourselves, and then study those problems because the same problems will be on the quiz. Now, my problem is, is that I really don't understand the subject, because professor just gives us these handouts and expects us to solve them by ourselves after a one minute quick explanation.

This handout has 12 problems, I know how to draw labels on them and do a free-body diagram... but I don't know how to do calculations... professor didn't help us do them, so I'm trapped in a paradox, I want to study for friday but have no material to study from. So, can you help me solve the CALCULATIONS (I know how to draw labels), so I can study and examine them by friday and not fail the quiz?

Since they are graphs and I can't draw here, I attached 5 well-visible images.

1st: http://img28.imageshack.us/img28/5849/nggw.jpg
2nd: http://img5.imageshack.us/img5/6608/81oz.jpg
3rd: http://img14.imageshack.us/img14/7445/xcup.jpg
4th: http://img30.imageshack.us/img30/5777/13x.JPG
5th: http://img35.imageshack.us/img35/8440/2uk.JPG

Here are my attempts but there's no chance they're correct:

1st: http://img849.imageshack.us/img849/6103/pxcq.jpg
2nd: http://img543.imageshack.us/img543/686/4r6u.jpg
 
Last edited by a moderator:
Physics news on Phys.org
BillTheButcher said:
1st: http://img28.imageshack.us/img28/5849/nggw.jpg
2nd: http://img5.imageshack.us/img5/6608/81oz.jpg
3rd: http://img14.imageshack.us/img14/7445/xcup.jpg
4th: http://img30.imageshack.us/img30/5777/13x.JPG
5th: http://img35.imageshack.us/img35/8440/2uk.JPG

Here are my attempts but there's no chance they're correct:

1st: http://img849.imageshack.us/img849/6103/pxcq.jpg
2nd: http://img543.imageshack.us/img543/686/4r6u.jpg
For the first problem, is there any difference between the magnitude of the tension acting on m and of the tension acting on M?

How is the acceleration of M related to the acceleration of m?

Can you write the equations for the accelerations of m and M and for the relationship between their accelerations? That should give you 3 equations and 3 unknowns (am, aM, and T) which you can now solve.

AM
 
Last edited by a moderator:
No, there's no difference between the magnitude of the tension in problem 1.

As for the acceleration, in those problems, we are supposed to find:
normal force
tension
acceleration

Masses will be given, as well as coefficient of friction (only kinetic friction).

As for equations, that's where I have a problem, I'm trying to have examples so I can then study those examples and solve new problems.
 
BillTheButcher said:
No, there's no difference between the magnitude of the tension in problem 1.

As for the acceleration, in those problems, we are supposed to find:
normal force
tension
acceleration

Masses will be given, as well as coefficient of friction (only kinetic friction).

As for equations, that's where I have a problem, I'm trying to have examples so I can then study those examples and solve new problems.
I'll give you the first equation.

From free-body diagram, add the force vectors to find the net force:

\vec{F_M} = M\vec{g} + \vec{T} = M\vec{a_M}

Since the net force is down, letting down be positive, the force magnitudes add this way:

F_M = Mg - T = Ma_M

Can you write the similar equation for m? Then relate the two accelerations.

AM