Tension At Two Points With Acceleration

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SUMMARY

The discussion revolves around calculating the force required for a painter to lift himself using a chair and pulley system. The painter has a mass of 90 kg, and the chair has a mass of 10 kg, resulting in a total mass of 100 kg. The required upward acceleration is 0.20 m/s². The participant correctly applies Newton's second law, F=MA, and derives the tension in the rope as T=(M(g+a))/2, ultimately calculating the force needed as 500 N.

PREREQUISITES
  • Understanding of Newton's second law (F=MA)
  • Basic knowledge of forces and tension in pulley systems
  • Familiarity with gravitational acceleration (g = 9.81 m/s²)
  • Ability to perform algebraic manipulations of equations
NEXT STEPS
  • Study advanced applications of Newton's laws in dynamic systems
  • Explore the mechanics of pulley systems in greater detail
  • Learn about the effects of friction in pulley arrangements
  • Investigate real-world applications of tension calculations in engineering
USEFUL FOR

Students studying physics, particularly those focusing on mechanics, as well as educators looking for practical examples of tension and force calculations in real-world scenarios.

myxomatosii
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Hi, I am here to ask a check to my work, I think that I have the idea down but I would like if someone could look over my concept and see if I am seeing things right as on my homework I used 3/5 of my attempts at the solution brashly without thinking, like a moron, I would like to check my next attempt here before I apply it there. :wink:

Homework Statement



A house painter uses the chair and pulley arrangement of Figure P8.42 to lift himself up the side of a house. The painter's mass is 90 kg and the chair's mass is 10 kg. With what force must he pull down on the rope in order to accelerate upward at 0.20 m/s^2?

http://img27.imageshack.us/img27/8056/p842.gif

Homework Equations


I believe the only formula needed is simple F=MA. F being the force of Tension. So I will say T=MA.

The Attempt at a Solution


First, forget the pully, man and chair.

Its just a mass of 100kg pulling itself up from a support point by another support point.

I believe to solve the problem I should take the acceleration(a) which I am trying to cause on the mass(M) and add it to the acceleration due to gravity(g), causing the total(A) to be 10.0m/s^2.

There, we have A and M. Simple.

The equation we could use to write this problem out (if we so chose at this point) would be.

2T=M(g+a) therefore T=(M(g+a))/2

Which gave me 500N.

I can't find a logic flaw, hopefully if there is one then you can.
 
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seems ok to me
 

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