How do you determine gravity with an experiment?

Question

How do you determine gravity with an experiment?

Answer 1

Drop stuff and time how long it takes to hit the ground.  Then use the basic kinematic equations to get the force acting on whatever you dropped.

Answer 2

What exactly is it about gravity that you wish to determine?

Answer 3

Use a balance beam, very precise scale and weigh a known mass, say,  m = .1 kg.

Weight, the force of gravity, is W = mg; where g = ? a measure of gravity's acceleration and W is the force of gravity.

If by "determine gravity," you mean the force of gravity the mass' weight W is the force of gravity.  If you mean the acceleration due to gravity g, then g = W/m, just divide the weight you got for the mass m.  

Note use kms SI units (kg, meter, second) if your scale is metric in Newtons.  Use slugs, feet, second if your scale is in pounds.