Question

which statements describe an object in motion that has no external force acting on it? check all that apply
it accelerates and speeds up.
it moves at a constant speed.
it decelerates and slows down.
it changes direction.
it moves in the same direction.

Explanation:

According to Newton's first law of motion (the law of inertia), an object with no external force acting on it will either remain at rest or continue moving in a straight line at a constant velocity (constant speed and same direction). Acceleration (speeding up, slowing down, or changing direction) requires a net external force. So "It moves at a constant speed" and "It moves in the same direction" are correct as no external force means no change in velocity (speed and direction). The other options involve acceleration (change in speed or direction) which needs a force.

Answer:

• It moves at a constant speed.
• It moves in the same direction.