Newton's Law of Inertia states than an object will keep a constant velocity unless acted upon by a unbalanced force.
To test this statement, Alex rolled a ball on a long level
street. The ball did not bump into any object, but it
eventually came to a stop? How is this possible?
Newton's 1st Law of Motion only holds true
in space, not on Earth.
Every moving object must come to a stop
because energy cannot be destroyed.
Alex didn't roll the ball hard enough, which
caused the ball to eventually stop rolling.
The unbalanced force that caused the ball
to stop was friction.