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Discussion: Homework Help Thread | Finals again.
Member Since: 1/3/2011
Posts: 30,381
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Quote:
Originally posted by Mickey
Hey - I'm a math major in college right now, and I got hired to TA a calculus class next semester. So if anyone has calculus questions I'd love to have some practice before the semester starts.. PM me
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have you taken a proofs class yet?
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Member Since: 5/18/2011
Posts: 17,136
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I guess I'm the only poor soul that's taken College Physics.
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Member Since: 9/4/2012
Posts: 4,435
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Quote:
Originally posted by I♥COCKiness
Has anyone taken or in Physics right now? I have a test tomorrow and I need to know how to work this problem:
A 50.0kg object is pushed by you on a level table. The acceleration is 1.00 m/s^2. The opposing frictional force on the object is 200N. What force must you apply to accelerate the object as described?
I know the answer is 250N, but can someone please show me how to work it and I will forever be grateful
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Don't think too much into it. You just have to use Force = Force of Applied - Force of Friction. Rearrange the equation to suit the question: Force of Applied = Force + Force of Friction.
Before you plug in, make sure you know Force. To find this, use Force = Mass x Acceleration. In your case that would be 50.0 kg x 1.00 m/s^2 = 50.0 N.
Plug 50 N in for Force. You already were given Force of Friction in the problem. So, 50 N + 200 N = 250 N, which is force needed to be applied to move the object.
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Member Since: 5/18/2011
Posts: 17,136
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Quote:
Originally posted by Quietly Trek
Don't think too much into it. You just have to use Force = Force of Applied - Force of Friction. Rearrange the equation to suit the question: Force of Applied = Force + Force of Friction.
Before you plug in, make sure you know Force. To find this, use Force = Mass x Acceleration. In your case that would be 50.0 kg x 1.00 m/s^2 = 50.0 N.
Plug 50 N in for Force. You already were given Force of Friction in the problem. So, 50 N + 200 N = 250 N, which is force needed to be applied to move the object.
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Thank you so much. I finally figured it out last night. I just finished my test. I'm pretty sure I passed.
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Member Since: 9/3/2011
Posts: 28,911
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Okay guys, I need help with a Earth Science LAB REPORT I have to type up tonight.
The lab was about density, and I wanted to know, does changing the size (volume) affect density?
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Member Since: 9/3/2011
Posts: 28,911
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I don't really pay attention in class as you can see
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Member Since: 2/20/2012
Posts: 14,955
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Is anyone here good at math, like from university. Proofs and calculus? I have trouble with some of the assignments, so next time I have an assignment I can ask someone.
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Member Since: 8/1/2012
Posts: 4,779
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Quote:
Originally posted by HausOfGerard
The lab was about density, and I wanted to know, does changing the size (volume) affect density?
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no, the density of 1 liter water is the same as the density of 100 liters water
unless you keep the mass fixed, like freezing water
then the V changes but the m doesn't change (density = m/V)
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Member Since: 9/3/2011
Posts: 28,911
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Quote:
Originally posted by Kingfisher
no, the density of 1 liter water is the same as the density of 100 liters water
unless you keep the mass fixed, like freezing water
then the V changes but the m doesn't change (density = m/V)
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Okay thanks. I mean the data we collected from the lab in the first situation changed a LITTLE but not that much, that's why I was confused because the density we collected in situation B changed quite alot.
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Member Since: 9/3/2011
Posts: 28,911
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I ****ing hate lab reports. Help.
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Member Since: 8/16/2011
Posts: 60,893
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Member Since: 9/3/2011
Posts: 28,911
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Quote:
Originally posted by rihannafan
how can i help you?
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I'm doing a lab report for Earth Science about density. One of the questions was "Did changing size (volume) of certain samples of Fluid A effect the density of Fluid A?" I now know the density doesnt change, but the data we collected, it changed a LITTLE. I don't know what to say.
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Member Since: 8/16/2011
Posts: 60,893
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Quote:
Originally posted by HausOfGerard
I'm doing a lab report for Earth Science about density. One of the questions was "Did changing size (volume) of certain samples of Fluid A effect the density of Fluid A?" I now know the density doesnt change, but the data we collected, it changed a LITTLE. I don't know what to say.
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give me the exact data please.
or if you can't, here's a solution: - If it changed a little (by a few units), then just say that they're about equal, as they should be and that the small difference is due to experimental errors. You might also need to state what might these errors be (false calculations, false measurements etc.)
- If there's a bigger difference, then either change your numbers if you want to cheat (not recommended), or say that you know that the results didn't come out as expected, and that the density should be equal no matter what the volume is, and proceed and state the possible errors that occured.
I've done a lot of chemistry reports in highschool and even before
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Member Since: 3/5/2011
Posts: 8,561
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Quote:
Originally posted by rihannafan
give me the exact data please.
or if you can't, here's a solution: - If it changed a little (by a few units), then just say that they're about equal, as they should be and that the small difference is due to experimental errors. You might also need to state what might these errors be (false calculations, false measurements etc.)
- If there's a bigger difference, then either change your numbers if you want to cheat (not recommended), or say that you know that the results didn't come out as expected, and that the density should be equal no matter what the volume is, and proceed and state the possible errors that occured.
I've done a lot of chemistry reports in highschool and even before
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A tad off topic, but I had to type up a lab yesterday for AP Chem, and I changed like all of my data to make it seem like our experiment was a success.
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Member Since: 8/16/2011
Posts: 60,893
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Quote:
Originally posted by Wonda
A tad off topic, but I had to type up a lab yesterday for AP Chem, and I changed like all of my data to make it seem like our experiment was a success.
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sometimes teachers find out I feel like it's more appropriate to just be honest.
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Member Since: 9/3/2011
Posts: 28,911
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The fluid A desities were : .846 g/mL, .837 g/mL and .845 g/mL with volumes of 15, 45 & 75.
The fluid B desities however were: .973 g/mL, 1.06 g/mL & 2.371 g/mL with volumes of 15, 45 & 75.
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Member Since: 8/16/2011
Posts: 60,893
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oh ok, the last figure is wrong. The others are right, and those variations are still tolerable imo. So either change the last one or do as i told you.
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Member Since: 6/22/2012
Posts: 26,585
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Does anybody know this?
What fat or oil has the highest percentage of polyunsaturated?
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Member Since: 9/3/2011
Posts: 28,911
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Quote:
Originally posted by rihannafan
oh ok, the last figure is wrong. The others are right, and those variations are still tolerable imo. So either change the last one or do as i told you.
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My teacher explained to us it was fine if we were off because it was our first lab report and she wouldnt take points off for data, but she said the lab report question answers have to be correct. Should I just say that volume doesn't affect density for it?
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Member Since: 8/16/2011
Posts: 60,893
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Quote:
Originally posted by HausOfGerard
My teacher explained to us it was fine if we were off because it was our first lab report and she wouldnt take points off for data, but she said the lab report question answers have to be correct. Should I just say that volume doesn't affect density for it?
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yes of course you should say that. Your results allow that general consensus anyway, especially the ones for fluid A.
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