Tension, pulley and acceleration problem

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SUMMARY

The discussion focuses on a physics problem involving two blocks connected by a cord over a frictionless pulley, with masses m1 = 3.3 kg and m2 = 5.1 kg. The correct acceleration calculated is 2.1 m/s². To find the tension in the cord, participants suggest applying Newton's Second Law separately to each mass and using the provided free body diagrams to derive the necessary equations. The weight of each block is calculated as 49.98 N for m2 and 32.34 N for m1, leading to a net force of 17.64 N used in the calculations.

PREREQUISITES
  • Understanding of Newton's Second Law (F=MA)
  • Knowledge of free body diagrams
  • Ability to calculate weight in Newtons (W=mg)
  • Familiarity with basic kinematics and acceleration concepts
NEXT STEPS
  • Learn how to derive tension in a pulley system using Newton's Second Law
  • Study free body diagram techniques for multi-body systems
  • Explore advanced problems involving frictionless pulleys and multiple masses
  • Investigate the effects of varying mass ratios on acceleration and tension
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Students studying physics, particularly those focusing on mechanics, as well as educators looking for problem-solving strategies in tension and acceleration scenarios.

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Homework Statement



In the figure below (part a), two blocks are connected by a lightweight, flexible cord that passes over a frictionless pulley.
(a) If m1 = 3.3 kg and m2 = 5.1 kg, what are the accelerations of each block?
(b) What is the tension in the cord?
fig-016.gif


Homework Equations





The Attempt at a Solution



I got the acceleration, a, to be 2.1, which is correct, but I cannot figure out how to get part b. I found the weight in Newtons of the 5.1 and 3.3 blocks, and then subtracted and used F=MA to find the acceleration. Can someone point me in the right direction about the tension? Thanks!
 
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maybe i didnt provide enough info... i found the weight in Newtons for the 5.1kg weight to be 49.98N, and 32.34N for the 3.3kg weight. I subtracted and got 17.64N. I did F=MA, with F being 17.64, m being 8.4 (or 5.1+3.3) and found a to be 2.1. Now I can't seem to find out how to do the tension part...

Thanks in advance for the help!
 
In order to find the tension you need to consider each mass separately and apply Newton's 2nd law. It looks like the free body diagrams for each mass are already given--translate them into equations and solve together. (Or, since you have the acceleration, you can just analyze one of the masses.)
 

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