Answer
Galileo discovered by experiment and reasoning that a moving object will continue in motion forever, in the absence of friction or other opposing forces.
Work Step by Step
This is discussed on pages 23-25.
You need to log in to continue
You can help us out by revising, improving and updating this answer.
Update this answerAfter you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.