Determining universal gravitational constant G

[Tony Manilla]

Homework Statement

Choose two masses and vary their separation, measuring the force between them each time. Plot a straight line graph and use the gradient to estimate the universal gravitational constant. Include uncertainties in the results and express values with the appropriate number of significant figures.
Im stumped...i could simply solve for G by inputing the variables i have (all except G) but i have to use the gradient of the graph.

Homework Equations

F= G*Mm/r^2
F=1/r^2

The Attempt at a Solution

i tried graphing Force vs 1/distance^2 and using the slope of it.

 

[drvrm]

Choose two masses and vary their separation, measuring the force between them each time.

i wonder how you will measure the force between the two chosen mass ?

 

[Tony Manilla]

It's a phet simulation but I figured it out. Just had to graph force vs inverse of distance squared and find the y intercept