- #1
Rigid Object in Equilibrium Problem please
- Thread starter gcombina
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- Equilibrium
In summary, the conversation discusses a problem involving a 3.0-kg and a 1.0-kg ball placed on a massless beam in equilibrium. The question is what is the ratio of the lengths of the beam, with options given as (a) 2.0, (b) 2.5, (c) 3.0, (d) 4.0, and (e) 5.0. The solution involves calculating the sum of torques and considering the effect of gravity. The answer is found to be b/a = 0.33, and the conversation ends with a humorous comment about impressing physicists and the importance of math in the medical field.
- #2
BvU
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Well, you formulated the problem, so we know what is asked in the exercise. What is your question, what are the relevant equations and what have you attempted to solve the problem?
- #3
BvU
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I see you did well in an earlier exercise which is very, similar to this one. Now there are only three forces. Pick a good point to calculate the sum of torques comfortably, and that's all!
- #4
gcombina
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lb = left ball
rb = right ball
SO I GOT 2 TORQUES
-(Tlb) (Llb) + - (Trb) (Lrb) = 0
-3kga - 1kgb = 0
-3kga = 1kgb
a = 1kgb/3kg
a= .33 b
rb = right ball
SO I GOT 2 TORQUES
-(Tlb) (Llb) + - (Trb) (Lrb) = 0
-3kga - 1kgb = 0
-3kga = 1kgb
a = 1kgb/3kg
a= .33 b
- #5
BvU
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Excellent! So b/a is in the list.
If you really want to delight physicists, you explicitly make clear that you did not forget g:
[itex]\sum[/itex] torques = 0 w.r.t. supported point [itex]\Leftrightarrow[/itex]
ma * g * (-La) + mb * g * (Lb) = 0 [itex]\Leftrightarrow[/itex] etc.
If you really want to delight physicists, you explicitly make clear that you did not forget g:
[itex]\sum[/itex] torques = 0 w.r.t. supported point [itex]\Leftrightarrow[/itex]
ma * g * (-La) + mb * g * (Lb) = 0 [itex]\Leftrightarrow[/itex] etc.
- #6
gcombina
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hahaha delight physicists? I am a language major trying to get into a physician assistance program and this course is just WAY TOO HARD 
- #7
gcombina
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OHHHH OK OK Let me try with the m.g
- #8
BvU
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The more respect you earn by passing !
Remember: physicists are lazy nerds. But not insensitive to this subtle way of flattering.
Remember: physicists are lazy nerds. But not insensitive to this subtle way of flattering.
- #9
BvU
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As I said, lazy. the etc means that from there it's "only" math.
Math is even more important for physicians assistants: if they can prevent the doctor from making a factor 10 mistake in their recipes even only once in their career, all the effort was well worth it!
Math is even more important for physicians assistants: if they can prevent the doctor from making a factor 10 mistake in their recipes even only once in their career, all the effort was well worth it!
- #10
gcombina
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prescriptions, not recipes...language major )
)FAQ: Rigid Object in Equilibrium Problem please
What is a rigid object in equilibrium problem?
A rigid object in equilibrium problem is a physics problem that involves analyzing the forces acting on a rigid object at rest. These problems typically require the use of Newton's Laws of Motion and other principles of physics to determine the unknown quantities, such as the forces or torques acting on the object.
How do I know if an object is in equilibrium?
An object is in equilibrium when the net force and net torque acting on it are equal to zero. This means that the object is not accelerating or rotating, and all the forces and torques acting on it cancel out. This can be determined by drawing a free body diagram and applying Newton's Laws of Motion.
What are the key steps to solving a rigid object in equilibrium problem?
The key steps to solving a rigid object in equilibrium problem are: 1) drawing a free body diagram, 2) determining the forces and torques acting on the object, 3) applying Newton's Laws of Motion, 4) setting up and solving equations to find the unknown quantities, and 5) checking the solution to ensure it satisfies the conditions for equilibrium.
Can a rigid object be in equilibrium if it is moving?
No, a rigid object cannot be in equilibrium if it is moving. Equilibrium means that the object is at rest, so if it is moving, there must be a net force acting on it. However, an object can be in dynamic equilibrium if it is moving at a constant velocity with balanced forces and torques acting on it.
What are some common types of rigid object in equilibrium problems?
Some common types of rigid object in equilibrium problems include: 1) objects on an inclined plane, 2) objects on a flat surface with multiple forces acting on it, 3) objects suspended by strings or ropes, and 4) objects with a pivot or fulcrum. These problems can also involve different types of forces, such as tension, friction, and normal forces.