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The Atwood machine consists of two masses hanging from the ends of a rope that passes over a pulley. The pulley is approximated as a uniform disk with a mass of 5.33 kg and a radius of 0.150 m. The hanging masses are 17.7 kg and 11.3 kg. Calculate the magnitude of the masses' acceleration, a, and the tension in the left and right ends of the rope, Tl and Tr, respectively.

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Final answer:

To find the magnitude of acceleration in an Atwood machine, Newton's second law of motion is applied to both masses, assuming a simplified system without the pulley's rotational effects. Once the acceleration is found, that value is used to calculate the tensions on each side of the pulley.

Step-by-step explanation:

Finding Acceleration and Tension in an Atwood Machine

To calculate the magnitude of the acceleration and the tension in the rope of an Atwood machine, we apply Newton's second law of motion (F = ma) to both masses. Let m1 = 17.7 kg and m2 = 11.3 kg be the masses of the left and right sides, respectively, and a be the acceleration of the system. The tension in the rope is different on both sides of the pulley due to its mass, which has both rotational inertial effects and contributes to the overall gravitational force.

To solve for acceleration, consider the net force on each mass. For m1:
Fnet = m1 * g - Tl = m1 * a
And for m2:
Fnet = Tr - m2 * g = m2 * a
Where g is the acceleration due to gravity (9.8 m/s²). However, as the pulley has mass, we also have to consider the rotational inertia of the pulley which introduces an additional factor to the tension equation. For simplicity, let's assume the pulley is massless and frictionless to find the acceleration. After finding acceleration using the massless pulley assumption, you can correct for the pulley's mass to find the exact tensions Tl and Tr.

Using the equations of motion for each mass and solving for acceleration, we get:
a = (m1 - m2) * g / (m1 + m2)
Since the pulley has mass, a complete solution would require us to calculate the moment of inertia of the pulley and use it to find an adjusted net force equation. However, we'll need the mass moment of inertia formula for a uniform disc: I = 0.5 * M * R², where M is the mass of the pulley and R its radius. This allows us to incorporate the pulley's inertia into the above equation, correcting the values for Tl and Tr.

Once you find the acceleration, you can apply it to either of the previous equations to solve for the tensions. Note that the side with the larger mass (m1) will have a lower tension compared to the other side because the system accelerates in the direction of m1.

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