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Newton's First Law of Motion states that moving objects will move forever, and resting objects will rest forever, unless some outside forces acts on them. Choose the BEST observation that supports Newton's First Law.
a. A ball that is not moving will remain still unless an outside force, such as a kick or push, acts on it to make it move.
b. A tennis ball when thrown into the air will bounce 14 times before it rests.
c. Friction is a force that changes the speed and direction of motion.
d. Gravity is a force that pulls objects toward Earth.
What is (a.)?