Ratio of two masses connected by pulley

In summary, the conversation was about finding the ratio of masses m1/m2 in a system where block 1 is connected to block 2 over a frictionless pulley. The blocks accelerate with a magnitude of a and the coefficient of kinetic friction between block 2 and the plane is μ. The solution involved setting up equations for the forces on each block and simplifying them to find the ratio. However, the final answer did not depend on Cosθ or Sinθ and the correct equation is m1/m2=(g(Cosθ - μSinθ))/(g-a). To check if the sin and cos are correct, one can consider an extreme case, like θ=π/2.
  • #1
Tasha9000
8
0

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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  • #2
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
 
  • #3
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?
 

FAQ: Ratio of two masses connected by pulley

What is the ratio of two masses connected by a pulley?

The ratio of two masses connected by a pulley is a mathematical expression that shows the relationship between the masses. It is determined by dividing the weight of the heavier mass by the weight of the lighter mass.

How do you calculate the ratio of two masses connected by a pulley?

To calculate the ratio of two masses connected by a pulley, you need to first determine the weight of each mass. Then, divide the weight of the heavier mass by the weight of the lighter mass. This will give you the ratio of the masses.

What factors affect the ratio of two masses connected by a pulley?

The ratio of two masses connected by a pulley is affected by several factors, including the weight of the masses, the friction in the pulley system, and the angle at which the pulley is placed. These factors can impact the accuracy of the calculated ratio.

Why is the ratio of two masses connected by a pulley important?

The ratio of two masses connected by a pulley is important because it helps determine the mechanical advantage of the pulley system. It is also used in various engineering and physics applications, such as calculating the force required to lift an object using a pulley system.

Can the ratio of two masses connected by a pulley be greater than 1?

Yes, the ratio of two masses connected by a pulley can be greater than 1. This indicates that the heavier mass has a greater weight than the lighter mass, resulting in a mechanical advantage for the pulley system.

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