- #1
Please somebody help me solving these questions
- Thread starter awaisamin20
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Discussion Overview
The discussion revolves around solving physics assignment questions related to moments, tension in strings, and free body diagrams. Participants seek clarification on specific problems presented in attached images, focusing on the correct application of concepts and methods in mechanics.
Discussion Character
- Homework-related
- Technical explanation
- Conceptual clarification
- Debate/contested
Main Points Raised
- One participant asks for guidance on calculating moments in a specific question, questioning whether to use point B as the reference point.
- Another participant suggests that moments should be calculated about the pivot point O, indicating that this approach avoids the complexity of finding the reaction force at O.
- A different participant proposes that the tension in a string is equal to the weight of the masses, questioning if multiple masses would result in a cumulative tension of 'nmg'.
- One participant challenges the previous claims, urging the use of a free body diagram and the total force equation for each mass separately.
- Another participant introduces a method involving adding and then removing a force at a specific point to analyze the problem differently, suggesting a trick to simplify the analysis.
Areas of Agreement / Disagreement
Participants express differing views on the correct approach to solving the problems, with no consensus reached on the methods to be used for calculating moments and tensions.
Contextual Notes
Participants have not provided complete details of the problems, and assumptions about the setup and definitions of forces and points are not fully clarified. The discussion reflects varying levels of understanding and interpretation of the physics concepts involved.
- #2
tiny-tim
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welcome to pf!
hi awaisamin20! welcome to pf!
show us what you've tried, and where you're stuck, and then we'll know how to help!
hi awaisamin20! welcome to pf!
show us what you've tried, and where you're stuck, and then we'll know how to help!
- #3
awaisamin20
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well in question 13(1st picture)...from which point i should calculate the moment??...i tried it with the point B...is it correct??...
- #4
tiny-tim
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no!
they mean the moments about the pivot point, O
(that way you don't need to find the reaction force at O, which would be very difficult!
)
they mean the moments about the pivot point, O
(that way you don't need to find the reaction force at O, which would be very difficult!
)try again!
- #5
awaisamin20
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- 0
in Question 14...2nd picture...as the tension in the string is equal to the weight...so if we consider every case seprately..each mass causes 'mg' tension in string..so will n no. of masses 'm' cause 'nmg' tension??..
- #6
awaisamin20
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- 0
tiny-tim said:no!
they mean the moments about the pivot point, O
(that way you don't need to find the reaction force at O, which would be very difficult!
try again!
which is the pivot point O here??
- #7
tiny-tim
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no, stop waffling …
do a proper free body diagram and Ftotal = 0 equation, for each mass (separately)
do a proper free body diagram and Ftotal = 0 equation, for each mass (separately)
- #8
pongo38
- 739
- 27
For the second diagram with the L shaped member with 10 and Mc on it ... in all fairness, there is a trick to this which involves adding a force at A and then taking it away at the same time, so that the result is unchanged. then you look at the enhanced diagram in a new way.
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