What causes a moving object to change its speed and/or direction of motion? What causes resting objects to begin moving? Both are due to (4) ___, which can be pushed or pulls on the objects. They can be hard to identify and understand. For example, a hand pushes on a box with force. This is called the (5) _, because the force on the box causes the box to move. However, the box also applies a force on the hand. This is the (6) _, and it is equal in size but opposite in direction. Together these two forces are called a (7) _. These forces are essential to understanding (8) ___, which states, "for every action, there is an equal and opposite reaction." fill in the blanks

Newton's laws of motion helps to explain the reason why motion is possible. For example, Newton's first law states that a body at rest or in uniform motion in a straight line will continue at rest or in uniform motion in a straight line unless acted upon by an external force. Newton's laws of motion provide answers to questions such as;

What causes a moving object to change its speed and/or direction of motion? What causes resting objects to begin moving? Both are due to forces, which can be pushed or pulled on the objects. They can be hard to identify and understand. For example, a hand pushes on a box with force. This is called the action, because the force on the box causes the box to move. However, the box also applies a force on the hand. This is the reaction, and it is equal in size but opposite in direction. Together these two forces are called a force pair. These forces are essential to understanding Newton's third law of motion, which states, "for every action, there is an equal and opposite reaction."