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!
Galileo would conduct an experiment with pendulum bobs of different masses, keeping the length constant to see if mass affects swing period. The period of a pendulum is determined by its length and gravitational acceleration, not mass, as shown by the formula T = 2 π g L . Thus, he would conclude that mass does not affect the period of a simple pendulum's swing.
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