Hi, I have been learning about graphical techniques, rearranging equations so they can be plotted on linear and log graph paper and things like that. I’ve been told if the law is in the form y=(a/x) +b then if y is plotted against 1/x a straight line graph is produced where a is the gradient and be is the intercept.

aswell as if y=ax^{2}+b and x^{2}is plotted against y a straight line is formed where a is the gradient and b is the intercept.

I’ve been given 2 examples but can’t seem to get the correct answer. I’ve been plotting these on normal graph paper and I’m not sure if that is what I’m doing wrong?

q1)

an experiment connected with the flow of a water over a area gave the following results

f 0.503 0.454 0.438 0.430 0.425 0.421 t 0.1 0.2 0.3 0.4 0.5 0.6 1/t 10 5 3.33 2.5 2 1.6

The relationship between f and t is thought to be f=a/t+b. test if so and find the values of a and b

Q2) the current for wires of various diameter is shown below

d(mm) 5 10 15 20 25 i amps 6.25 10 16.25 25 36.25 d ^{2}25 100 225 400 625

it is suggested this data follows I=ad^{2}+b. by plotting a graph show that the law holds and find the constants a nd b

any help with solving these would be great, I’m not sure if i have to use normal graph paper or log log paper?

on another note if I use the data in the table is there a way of working out the values with out plotting the graph

any help would be truly appreciated.

Thanks