- #31
anglum
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- 0
i have the ma+mg stuck in my head. and drawing it isn't helpin me in explaining to u where i am
Calculate the initial velocity of the elevator
- Thread starter anglum
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Homework Help Overview
The discussion revolves around calculating the initial velocity of a descending elevator that is uniformly decelerated to rest. The problem involves concepts from mechanics, specifically forces, acceleration, and kinematics.
Discussion Character
- Mixed
Approaches and Questions Raised
- Participants explore the relationship between tension, mass, and acceleration, with some suggesting the use of kinematic equations to find the initial velocity. Others mention the possibility of using work-energy principles, although not all participants are familiar with this method.
Discussion Status
There is an ongoing exploration of the problem, with participants sharing their calculations for acceleration and discussing the signs to use in kinematic equations. Some participants express confusion regarding the application of formulas and the interpretation of variables.
Contextual Notes
Participants note that they have not covered certain concepts, such as work-energy, and there are discussions about the correct application of signs in equations. There is also mention of converting units, which adds to the complexity of the problem.
- #32
learningphysics
Homework Helper
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It is always best to start your force problems by writing out the equations in the form:
\Sigma{F} = ma
and going from there... don't take shortcuts.
\Sigma{F} = ma
and going from there... don't take shortcuts.
- #33
anglum
- 275
- 0
the force the earht exerts is
x = MA
x = 65*9.8
x=637N
x = MA
x = 65*9.8
x=637N
- #34
learningphysics
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anglum said:
don't get stuck with the ma + mg... always start from the basics...
\Sigma{F} = ma.
But anyway, for this problem, what is the force the Earth exerts on the student?
- #35
learningphysics
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anglum said:
yes. So what is the force the student exerts on the earth?
- #36
anglum
- 275
- 0
the student exerts
X=5.98*10^24 * A
X=5.98*10^24 * A
- #37
anglum
- 275
- 0
does X in this also equal 637N
- #38
learningphysics
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anglum said:
exactly.
- #39
anglum
- 275
- 0
so then i solve it as 637/5.98*10^24 = A
A = 1.065217 *10^-22
A = 1.065217 *10^-22
- #40
anglum
- 275
- 0
awesome... thank you soooooo much for all your help tonite... u are a very patient man and a very good teacher
- #41
learningphysics
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anglum said:
you're welcome. glad to help. keep at it! you're doing well!