Simple Machines B/Compound Machines C

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Re: Simple Machines B/Compound Machines C

Post by Unome » April 28th, 2015, 3:01 pm

plaid suit guy2 wrote:You sure?
The first problem is this
divcanswer.png
Try the second question.
Wait... shouldn't be 10N?
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Re: Simple Machines B/Compound Machines C

Post by plaid suit guy2 » April 28th, 2015, 3:04 pm

Unome wrote:
plaid suit guy2 wrote:You sure?
The first problem is this
divcanswer.png
Try the second question.
Wait... shouldn't be 10N?
...yes
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Nationals 2012:
Sound of Music: 8th

Nationals 2013:
Remote Sensing: 1st
ELG: 1st
MagLev: 6th

State 2014:
Boomi: 1st (scored 1824)
Circuits: 1st
Compound: 3rd
Malgev: 1st
MP: 2nd

total gold: 18
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total bronze: 5
6th: 1
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Re: Simple Machines B/Compound Machines C

Post by Unome » April 28th, 2015, 3:05 pm

plaid suit guy2 wrote:
Unome wrote:
plaid suit guy2 wrote:You sure?
The first problem is this
divcanswer.png
Try the second question.
Wait... shouldn't be 10N?
...yes
So ?
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Re: Simple Machines B/Compound Machines C

Post by plaid suit guy2 » April 28th, 2015, 3:08 pm

It't just ends up as 27.84N (exactly as written on the piece of paper I wrote the solution on last night at like 10:30. Tired me is better as physics, as it turns out :P)

done correctly
divcanswer.png
blue and yellow plaid suit
Nationals 2012:
Sound of Music: 8th

Nationals 2013:
Remote Sensing: 1st
ELG: 1st
MagLev: 6th

State 2014:
Boomi: 1st (scored 1824)
Circuits: 1st
Compound: 3rd
Malgev: 1st
MP: 2nd

total gold: 18
total silver: 10
total bronze: 5
6th: 1
Poudre High School class of '15

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Re: Simple Machines B/Compound Machines C

Post by Unome » April 28th, 2015, 3:14 pm

plaid suit guy2 wrote:It't just ends up as 27.84N (exactly as written on the piece of paper I wrote the solution on last night at like 10:30. Tired me is better as physics, as it turns out :P)

done correctly
divcanswer.png
Ohh... I just made a math error, subsequently fixed it to figure out how to solve the problem, then remade the same error while actually calculating the answer...
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Re: Simple Machines B/Compound Machines C

Post by plaid suit guy2 » April 28th, 2015, 3:17 pm

I did too, so it's all good. Oh, also,
UTF-8 U+6211 U+662F wrote:
plaid suit guy2 wrote:You sure?
The first problem is this
divcanswer.png
Try the second question.
Now I get it. I forgot the part... :oops:
4 kg
except... shouldn't the weight of the lever arm increase as the arm goes further away from the fulcrum?
This is an incorrect answer. The weight doesn't increase with the distance, the torques do, but there is a mathematical shorthand: you can assume all of the mass is at the center of mass of the beam, its halfway point.
blue and yellow plaid suit
Nationals 2012:
Sound of Music: 8th

Nationals 2013:
Remote Sensing: 1st
ELG: 1st
MagLev: 6th

State 2014:
Boomi: 1st (scored 1824)
Circuits: 1st
Compound: 3rd
Malgev: 1st
MP: 2nd

total gold: 18
total silver: 10
total bronze: 5
6th: 1
Poudre High School class of '15

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Re: Simple Machines B/Compound Machines C

Post by UTF-8 U+6211 U+662F » April 28th, 2015, 5:17 pm

plaid suit guy2 wrote:I did too, so it's all good. Oh, also,
UTF-8 U+6211 U+662F wrote:
plaid suit guy2 wrote:You sure?
The first problem is this
divcanswer.png
Try the second question.
Now I get it. I forgot the part... :oops:
4 kg
except... shouldn't the weight of the lever arm increase as the arm goes further away from the fulcrum?
This is an incorrect answer. The weight doesn't increase with the distance, the torques do, but there is a mathematical shorthand: you can assume all of the mass is at the center of mass of the beam, its halfway point.
Yeah, I meant the torque. :P
I tried doing that, but the lever arm itself ended up having more torque then both the other arm and the weight together, so...

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Re: Simple Machines B/Compound Machines C

Post by plaid suit guy2 » April 28th, 2015, 5:33 pm

UTF-8 U+6211 U+662F wrote:
plaid suit guy2 wrote:I did too, so it's all good. Oh, also,
UTF-8 U+6211 U+662F wrote: Now I get it. I forgot the part... :oops:
4 kg
except... shouldn't the weight of the lever arm increase as the arm goes further away from the fulcrum?
This is an incorrect answer. The weight doesn't increase with the distance, the torques do, but there is a mathematical shorthand: you can assume all of the mass is at the center of mass of the beam, its halfway point.
Yeah, I meant the torque. :P
I tried doing that, but the lever arm itself ended up having more torque then both the other arm and the weight together, so...
yes, it does
blue and yellow plaid suit
Nationals 2012:
Sound of Music: 8th

Nationals 2013:
Remote Sensing: 1st
ELG: 1st
MagLev: 6th

State 2014:
Boomi: 1st (scored 1824)
Circuits: 1st
Compound: 3rd
Malgev: 1st
MP: 2nd

total gold: 18
total silver: 10
total bronze: 5
6th: 1
Poudre High School class of '15

UTF-8 U+6211 U+662F
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Re: Simple Machines B/Compound Machines C

Post by UTF-8 U+6211 U+662F » April 28th, 2015, 5:43 pm

plaid suit guy2 wrote:
UTF-8 U+6211 U+662F wrote:
plaid suit guy2 wrote: This is an incorrect answer. The weight doesn't increase with the distance, the torques do, but there is a mathematical shorthand: you can assume all of the mass is at the center of mass of the beam, its halfway point.
Yeah, I meant the torque. :P
I tried doing that, but the lever arm itself ended up having more torque then both the other arm and the weight together, so...
yes, it does
Then the load has to have negative weight...
I just figured you did something wrong, so I just did the question wrong...

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Re: Simple Machines B/Compound Machines C

Post by Unome » April 28th, 2015, 6:27 pm

[math](10 m)(20/25*20 kg) + (15 m)(x kg) = (5 m)(15 kg) + (2.5 m)(4 kg)[/math]
[math]x=5kg[/math]
Definitely negative
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