Galileo conducted controlled experiments to find out if the mass of the pendulum bob affected the period of the swing. write a description of how he might design his experiment.

According to my guesses, he should have swung the pendulam bob and noted its time period. In order to observe the effect of mass, he would have repeated the experiment with varied pendulam bobs. Hope this helped! 

Pe = 1/2k(x)^2  and .05n/m = .05x10^-9m = x