Solving Atwood's Machine: Find Forces & Acceleration

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SUMMARY

The discussion focuses on solving Atwood's Machine by calculating the acceleration of two masses and the tension in the connecting string. Using Newton's laws of motion, the equations derived are T - m1g = m1a for the first mass and m2g - T = m2a for the second mass. The acceleration is determined as a = (m2g - m1g)/(m1+m2), and the tension in the string is calculated as T = (m1m2g)/(m1+m2). Testing the results can be done through practical experiments with varying masses and measuring acceleration and tension.

PREREQUISITES
  • Understanding of Newton's laws of motion
  • Ability to draw free body diagrams
  • Familiarity with basic physics concepts such as force, mass, and acceleration
  • Knowledge of using force sensors for experimental validation
NEXT STEPS
  • Learn how to derive equations of motion for systems with multiple masses
  • Explore practical applications of Atwood's Machine in physics experiments
  • Study the effects of friction and pulley mass on tension and acceleration
  • Investigate advanced topics such as non-ideal pulleys and their impact on calculations
USEFUL FOR

Students studying physics, educators teaching mechanics, and anyone interested in experimental physics and the application of Newton's laws in real-world scenarios.

jungleismassiv
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The machine shown in the figure below can be used to give you a good feel
for forces. Assuming a massless, frictionless pulley and a massless string,
calculate the magnitude of the acceleration on both bodies and the tension in
the string T.

http://img110.exs.cx/my.php?loc=img110&image=d9kq.jpg

Find the force exerted by the Atwood's machine on the hanger which the
pulley is attached to while the blocks accelerate. Neglect the mass of the
pulley.

The pulley in Atwood machine above is given an upward acceleration a. Find
the acceleration of each mass and the tension in the string that connects
them. How can you test your result

No idea with these questions. Any help would be appreciated. Thanks :smile:
 
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No idea is not good enough for help.
Try to explain what you think MIGHT work, but why you are uncertain about it.
 


Solving Atwood's Machine involves applying the principles of Newton's laws of motion. In this machine, there are two masses connected by a string that passes over a frictionless and massless pulley. The first step in solving this problem is to draw a free body diagram for each mass, showing all the forces acting on them. In this case, there are two forces acting on each mass - the weight (mg) and the tension in the string (T).

Now, using Newton's second law (F=ma), we can write an equation for each mass:

For the first mass (m1):
T - m1g = m1a

For the second mass (m2):
m2g - T = m2a

Since the pulley is massless, we can assume that the tension in the string (T) is the same on both sides. We can also assume that the acceleration of the two masses is the same, as they are connected by a string. Therefore, we can combine the two equations and solve for the acceleration (a):

T - m1g = m1a
m2g - T = m2a

Adding the two equations, we get:
m2g - m1g = (m1+m2)a

Solving for a, we get:
a = (m2g - m1g)/(m1+m2)

This is the acceleration of both masses. To find the tension in the string (T), we can substitute this value of acceleration in any of the two equations we wrote earlier. For example, using the first equation:
T - m1g = m1a
T - m1g = m1[(m2g - m1g)/(m1+m2)]
T = (m1m2g)/(m1+m2)

Therefore, the tension in the string is:
T = (m1m2g)/(m1+m2)

To test our result, we can perform a simple experiment using this Atwood's machine. We can vary the masses and measure the acceleration and tension in the string using a force sensor. We can then compare our calculated values with the measured values to see if they match. If there is a significant difference, we can check for any errors in our calculations and make necessary adjustments. This way, we can verify the accuracy of our solution.
 

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