Physics: a question about Experiments

mike-gunners

How do you find the slope of a graph? Do u just take two points on the graph and put one over the other and divide?if not how do u do it?

hippety-pippety

to get the slope you take a value on the y-axis and put it over the corresponding value on the x-axis
like in maths: m= (Y2-Y1)/(X2 - X1), and in physics you only need one y-value & one x-value so the slope = y/x

declan_lgs

slope is Y change over X change.

Most graphs are straight lines through the origin, therefore you know (0,0) is on the graph and can just pick a point that's on the line and put it's Y coord over its X coord.

mike-gunners

hippety-pippety wrote: »

to get the slope you take a value on the y-axis and put it over the corresponding value on the x-axis
like in maths: m= (Y2-Y1)/(X2 - X1), and in physics you only need one y-value & one x-value so the slope = y/x

thanks a million man.
these are the expts that i learned off today:
1. a <>< f
2. g by free fall
3. boyle's law
4. specific latent heat of fusion of ice
5. specific latent heat of vaporisation of water
6. Calibration curve of a thermometer
7. variation of frequency with length
8. variation of frequency with tension
9. variation of resistance of metallic conductor with temperature
10.variarion of resistance of thermistor with temperature
11.measure of resistivity of nichrome wire.

Do u think i m covered for the experiments or would u recommend other ones in addition with these?

The Walsho

On a related topic, I tend to have trouble deciding which value goes on the X-axis and which goes on the Y-axis for experiments. Can anyone shed some light? For example, with Boyle's Law, which goes on the X-axis, P or 1/V ?

Peleus

The Walsho wrote: »

On a related topic, I tend to have trouble deciding which value goes on the X-axis and which goes on the Y-axis for experiments. Can anyone shed some light? For example, with Boyle's Law, which goes on the X-axis, P or 1/V ?

ye i always have trouble with that. usually if there's a 1/ something, i'd put that on the X axis. I don't think it matters which axis you put them on, you get the same shape. Usually current, temperature goes on the Y axis and time, voltage go on the X axis. I'm not sure about that but i'm pretty sure thats usually the case.

The Walsho

Cheers Peleus.

salman85

THEY MUST BE ON THE LINE (some times a point you plot doesnt go through the line)

if u use that point ur slope will be diffrent

IT MUST BE ON THE LINE

and for axes

what u control goes on X what changes as a result goes on Y

remember f(x) is a function of X

A-Bit-Dodge

if u use y=mx for most of the equations for the experiments, you shouldnt go wrong...

Example
: F=ma
: y=mx


Force goes on y axis, acceleration goes on x axis.

R=V/I
V=IR
y=mx

Voltage goes on y axis, current goes on x axis...