In an experiment to determine the density of a substance the following results were obtained. Use the results to plot a graph of mass against volume.
Mass (g) 10 20 30 40 50 60 70 80 90
Volume (cm 3 ) 0.5 1.0 1.4 2.0 2.2 2.6 3.0 3.6 4.5

a) Find the gradient of the graph.
b) What does the gradient represent?
c) What is the mass when the volume is 1.5cm 3 ?
d) What is the volume when the mass is 65g?

a) Gradient = rise/run = mass/volume

since the graph is mass against volume we know mass is on the y-axis and volume is on the x-axis

in physics it’s best to use a larger part of the graph to find the gradient, so imma use the biggest values.

90/4.5 = 20

(additional note: sometimes you may get a different gradient. For example, when using 30 and 1.4 you get ≈21 this is an anomalous result since ita gradient differs; a mass against volume graph is supposed to be linear)

b) gradient represents density (p) since gradient is = mass/volume. And density also = mass/volume

For c and d just plot the points and you’ll be able to read from the graph to get the values.

I got this graph (the image)

but you’ll be able to interpret better when ‘you’ draw it (so try plotting it)

option number c is the right answer.