Combine the expressions for tension and solve for acceleration

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Homework Help Overview

The discussion revolves around deriving an equation for the acceleration of a cart and a suspended mass on an incline, involving the masses of the cart (Mc) and the suspended mass (Ms), the angle of the incline (θ), and the acceleration due to gravity (g).

Discussion Character

  • Exploratory, Mathematical reasoning, Assumption checking

Approaches and Questions Raised

  • Participants discuss combining equations related to tension and acceleration, with attempts to derive a formula for acceleration. There are questions about the notation used for the masses and the reasoning behind introducing different variables.

Discussion Status

Some participants have shared their attempts at combining equations and expressed uncertainty about their methods. A hint has been provided regarding the elimination of unknown variables when combining equations, suggesting a productive direction in the discussion.

Contextual Notes

There is a mention of an image that contains a derived equation, which some participants reference for clarity. Additionally, there is confusion regarding the notation for the masses, as different symbols are used in the image compared to the participants' posts.

asusal
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1. Derive an equation for the acceleration of both the cart and suspended mass in
terms of both masses (Mc and Ms ), the angle of the incline (θ), and the acceleration due to gravity (g).


Homework Equations


Fx=
T - Mgsin θ = Ma

T = Mgsin θ + Ma
Fy
T = mg - ma

Combine the expressions for Tension and solve for the acceleration.

A= (mg - Mg sin θ / M + m )

https://imgur.com/a/Okk79t9 (I know in the picture it's already derived in the correct form I just want to know how they got that correctly.)[/B]

The Attempt at a Solution



So I combined the equations

T= (ms*g-mc*g*sin(θ) ) / ( mc + mg)

T= ms (g- (ms*g-mc*g*sin θ/ mc+ms) )

[/B]
I'm assuming I factor MS and common denom but it doesn't seem like I'm doing this correctly.
Any help would be appreciated!

Thanks.
 
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cart.jpg
 

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asusal said:
So I combined the equations
T= (ms*g-mc*g*sin(θ) ) / ( mc + mg)
T= ms (g- (ms*g-mc*g*sin θ/ mc+ms) )

I'm assuming I factor MS and common denom but it doesn't seem like I'm doing this correctly.
Any help would be appreciated!

Can you show more of your working?

Why introduce ms and mc ? In the image they use "M" for the mass of the cart and "m" for the suspended mass. I suggest you stick to that notation.
 
Hint: When you combine two equations you can frequently eliminate one unknown variable. Which unknown doesn't appear in the final equation given to you?
 

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