EPT
noob phys question
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nAi.PrOtOsS
Canada784 Posts
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Caller
Poland8075 Posts
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Ilikestarcraft
Korea (South)17733 Posts
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IzzyCraft
United States4487 Posts
It's best fit line | ||
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Ilikestarcraft
Korea (South)17733 Posts
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fusionsdf
Canada15390 Posts
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IntoTheWow
is awesome32277 Posts
On September 17 2008 11:26 Ilikestarcraft wrote: 1+1=11? 1+1 = 1 1+1 = 10 1+1 = 2 | ||
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IntoTheWow
is awesome32277 Posts
Find the derivative of the function and evaluate in the point where you want to find the slope. | ||
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Purind
Canada3562 Posts
I reckon the next question is gonna be "what does rise over run on a log log graph mean?" | ||
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XCetron
5226 Posts
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caelym
United States6421 Posts
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imperfect
Canada1652 Posts
after graphing the line, just simply measure the slope with a ruler? ie: rise over run, which would mean for example, 25mm over 50 mm or something like that in which case the slope would be 1/2. | ||
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nAi.PrOtOsS
Canada784 Posts
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IntoTheWow
is awesome32277 Posts
As long as you stay in range (where the slope is constant, and the function is linear) your calculations will be fine. | ||
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economist_
Vietnam719 Posts
Linear function always has the constant slope... | ||
micronesia
United States24760 Posts
+ Show Spoiler + OVER 9000! | ||
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IntoTheWow
is awesome32277 Posts
On September 17 2008 12:53 micronesia wrote: What percent of the people here responded while having no idea what log-log means? + Show Spoiler + OVER 9000! Wouldn't it be "Over 3.95424251!!!"? | ||
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IzzyCraft
United States4487 Posts
On September 17 2008 12:53 micronesia wrote: What percent of the people here responded while having no idea what log-log means? + Show Spoiler + OVER 9000! Doesn't matter slope is always best fit line or learn how to write algorithms. | ||
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micronesia
United States24760 Posts
On September 17 2008 13:20 IzzyCraft wrote: Doesn't matter slope is always best fit line or learn how to write algorithms. Wat? I was just saying some people were assuming the question was 'how do I find slope' even though the OP obviously knows how to find the slope of a line lol | ||
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Hypnosis
United States2061 Posts
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Purind
Canada3562 Posts
On September 17 2008 12:03 nAi.PrOtOsS wrote: Ok so my teacher says that as long as the log-log graph is linear then it's correct and you can find the slope and then use that in other calculations. Is it possible tho, to have a linear log-log graph but be completely wrong? so the slope of that incorrect linear line would completely mess up all the calculations? Depends on what you're graphing. If it's supposed to be exponential, then I think it should be linear on a log log | ||
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Underwhelmed
United States207 Posts
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Ilikestarcraft
Korea (South)17733 Posts
On September 17 2008 12:53 micronesia wrote: What percent of the people here responded while having no idea what log-log means? + Show Spoiler + OVER 9000! i dont know what log log is im just sortof annoyed because ops been making a lot of threads like this lately. Im not saying asking for help is bad i used to make threads like these too. | ||
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jgad
Canada899 Posts
On September 17 2008 13:20 IzzyCraft wrote: Doesn't matter slope is always best fit line or learn how to write algorithms. That's not true. If you plot a straight line (linear function) on a log-log graph you get a straight line with a slope of 1, regardless of what the slope would be on a linear-linear graph. If you plot a quadratic equation on a log-log graph, you get a straight line with a slope of 2, not a curving line. My guess is that this exercise is about learning to interpret the shape of plots in logarithmic form and to understand the congruency between different forms of the same plot. | ||
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jgad
Canada899 Posts
On September 17 2008 13:53 Purind wrote: Depends on what you're graphing. If it's supposed to be exponential, then I think it should be linear on a log log Nah, exponential still curves on a log-log graph. It's a straight line on a log-lin graph. | ||
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sigma_x
Australia285 Posts
"Ok so my teacher says that as long as the log-log graph is linear then it's correct and you can find the slope and then use that in other calculations. Is it possible tho, to have a linear log-log graph but be completely wrong? so the slope of that incorrect linear line would completely mess up all the calculations?" This will depend on what your actually trying to find. This will be fine if you the actual question features a linear component in logs. For example, y=1/2 g t^2 [which is the distance travelled by a falling object due to gravity] can be put in the form y=mx+b by taking logs of both side. so, logy=2(logt) +log(1/2 g), which is linear on a log log graph. Notice that in this example, the gradient tells you the power of "t", so if your gradient is roughly "2" it shouldn't interfere with your calculations too much. | ||
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Maenander
Germany4926 Posts
On September 17 2008 12:53 micronesia wrote: What percent of the people here responded while having no idea what log-log means? + Show Spoiler + OVER 9000! If the OP asks stupid questions, he gets stupid answers. That´s perfectly fine. | ||
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fight_or_flight
United States3988 Posts
log(y) = slope*log(x) + intercept 10^log(y) = 10^(slope*log(x) + intercept) y = x^slope*10^intercept y = (10^intercept)*x^slope ? | ||
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micronesia
United States24760 Posts
On September 17 2008 16:56 Maenander wrote: If the OP asks stupid questions, he gets stupid answers. That´s perfectly fine. He's asked too many questions lately, and the OP was too short, and he could have been more clear, but it wasn't actually stupid imo. Not his fault people don't know what log-log is but reply anyway. | ||
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