Ratio of two masses connected by pulley

AI Thread Summary
The discussion focuses on finding the ratio of two masses, m1 and m2, connected by a pulley, considering the effects of friction and acceleration. The initial attempt to derive the ratio resulted in an incorrect equation that included trigonometric functions, which was pointed out as a mistake. The correct formula should not depend on Cosθ or Sinθ, leading to the realization that the expression should be m1/m2=(g(Cosθ - μSinθ))/(g-a). Participants also discussed verifying the correctness of the equations by testing extreme cases, such as θ=π/2, to ensure the components were accurately represented. Overall, the conversation emphasizes the importance of correctly applying physics principles to solve the problem.
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Homework Statement

[/B]
Figure 1) Block 1, of mass m1, is connected over an ideal (massless and frictionless) pulley to block 2, of mass m2, as shown. Assume that the blocks accelerate as shown with an acceleration of magnitude a and that the coefficient of kinetic friction between block 2 and the plane is μ.

Find the ratio of the masses m1/m2.
Express your answer in terms of some or all of the variables a, μ, and θ, as well as the magnitude of the acceleration due to gravity g.
MLD_2l_2_v2_2_a.jpg

Homework Equations


Fnet=ma
Ff=muN
W=mg

The Attempt at a Solution



+ /x is direction of acceleration

Forces on m2

y-axis
N - mgy=0

x-axis
T - m2gx-Ff=m2a

T - m2g Cosθ - μm2Sinθ=m2a

Forces on m1

m1g - T = m1a

Attempt

I just put all the equations into one and got:

m1/m2=(g(Cosθ - μSinθ))/(g/a)

but it still says it's wrong. It says the final answer doesn't depend on Cosθ or Sinθ
 
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Tasha9000 said:

Homework Statement

[/B]
Figure 1) Block 1, of mass m1, is connected over an ideal (massless and frictionless) pulley to block 2, of mass m2, as shown. Assume that the blocks accelerate as shown with an acceleration of magnitude a and that the coefficient of kinetic friction between block 2 and the plane is μ.

Find the ratio of the masses m1/m2.
Express your answer in terms of some or all of the variables a, μ, and θ, as well as the magnitude of the acceleration due to gravity g.
MLD_2l_2_v2_2_a.jpg

Homework Equations


Fnet=ma
Ff=muN
W=mg

The Attempt at a Solution



+ /x is direction of acceleration

Forces on m2

y-axis
N - mgy=0

x-axis
T - m2gx-Ff=m2a

T - m2g Cosθ - μm2Sinθ=m2a

Forces on m1

m1g - T = m1a

Attempt

I just put all the equations into one and got:

m1/m2=(g(Cosθ - μSinθ))/(g/a)

but it still says it's wrong. It says the final answer doesn't depend on Cosθ or Sinθ

it should be m1/m2=(g(Cosθ - μSinθ))/(g-a)

I also probably messed up the components but I tried both ways
 
To check whether I have sin and cos the right way round, I consider an extreme case, like ##\theta=\pi/2##. Do your equations look right for that case?
 
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