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Dependent, Independent Variables??? (1 Viewer)

Nelly

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What are the Independent, and dependent variables. And what is a control? Thank You.

Could this please be answered ASAP. Thank You
 

quartic

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The independant variable is the thing that dosn't depend on the other variables in the equation. For example if you were looking at the way something changed with time then time is the independant variable since it dosn't depend on anything else. Similarly if you were mesuring period of a pendulum against length the length would be the independant variable because the period is dependant on length but the length isn't determined by period.

A control is usually a duplicate experiment run concurrently with your main experiment except you keep constant the variable you are testing so that you can eliminate any other source of variation, or so you can be sure the variable you are testing is causing any changes you see.

That wasn't a very good explanation but I hope it helps.
 

KingofthieF

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Great Answer quartic!~!

omg that is a sick answer there quartic!

btw as seen in the examples given by quartic, though time is usually the independent variable... it may not be so in all cases... so you gotta look at the situation carefully. In addition, when you graph the result, independent variable is always along the x-axis and the dependent variable on the y-axis... Don't get it mixed up :)
 

Nelly

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We're doing an experiment for Astrophysics tomorrow. What are some things that could generally be improved in an experiment, and assessing the reliability of an experiment.

BTW, does the line of best fit have to be a straight line
 

gigi

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>>No the line of best fit dosn't have to be straight

bullshit!! YES IT DOES!!!!!!
it is a line. adding up the distance between point on either side they should be equal. if one point puts the line out heaps just call it an outlying point and ignore it
 
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the line of best fit doesnt have to be a line. Nelly, you should know that by now, how many times have you lost marks for that?
 

Nelly

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I know Deliva said that, but what if other schools think it is a straight line. Arash said that his school was taught that its a straight line, and this chic does. So maybe it is. But tomorrow, I will obviously not be doing that. :p

Who here has been taught that the line of best fit is straight???
 

Lazarus

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Originally posted by gigi
>>No the line of best fit dosn't have to be straight

bullshit!! YES IT DOES!!!!!!
it is a line. adding up the distance between point on either side they should be equal. if one point puts the line out heaps just call it an outlying point and ignore it
The method that you've outlined partially describes a 'least squares regression' line, which is a type of best fit line. In the HSC physics course, I *think* you're allowed to have parabolic lines of best fit etc.

The dependent variable is whatever you're measuring in the experiment.

The independent variable is whatever you're manipulating in the experiment.

The control variables are anything that would be variable in a normal situation (and that may affect the dependent variable) but that you are holding constant because you're doing a lab experiment.
 

quartic

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If the data points are obviously creating an exponential series then you have to draw it that way. If the data points are close to a straight line then it should obviously be a straight line. The line of best fit describes the most likely path of the relationship you are graphing if you had many data points and very little experimental error.
 

gigi

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my humblest apologies, you guys are right. doesn't have to be a straight line. i was just having one of those days.

I'm so sorry. I was pretty rude about it too, can't believe I wrote that. sorry

gigi
 

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