Any change in speed or direction requires a __________.

Any change in speed or direction requires a __________.

• A. Motion
• B. Force
• C. Acceleration
• D. Energy

Answer: (B)

A change in speed or direction happens when something outside the object pushes or pulls on it. That change in velocity is called acceleration, the rate at which speed and/or direction change. A net force is what creates that acceleration. For example, pushing a rolling toy makes it speed up; braking slows it down; steering a bicycle changes its direction. If no net force acts on the object, it would keep moving at the same speed and in the same direction. So the blank is force, because it is what causes the change in motion.

A change in speed or direction happens when something outside the object pushes or pulls on it. That change in velocity is called acceleration, the rate at which speed and/or direction change. A net force is what creates that acceleration. For example, pushing a rolling toy makes it speed up; braking slows it down; steering a bicycle changes its direction. If no net force acts on the object, it would keep moving at the same speed and in the same direction. So the blank is force, because it is what causes the change in motion.