Physics Review

2. A push or a pull that can cause an object to start moving, stop moving, or change direction.
5. In physics, this refers to a force applied by one object onto a second object. It's the "doing" part of a force pair.
7. In physics, this is the equal and opposite force that the second object applies back onto the first object. It's the "response" to the action force.
9. The ability to do work or cause change. It exists in many forms, like light, heat, sound, and motion.
10. Forces acting on an object that are not equal in size and/or are not opposite in direction. When forces are unbalanced, the object accelerates (changes its motion).
11. A force of attraction between any two objects that have mass. On Earth, it is the force that pulls everything down toward the planet's center.
12. Forces acting on an object that are equal in size and opposite in direction. When forces are balanced, the object's motion doesn't change (it stays still or keeps moving at the same speed).

1. The speed of an object in a specific direction. It tells you how fast something is moving and where it is going.
3. The amount of matter in an object. It is a measure of an object's inertia.
4. The tendency of an object to resist changes in its motion. An object at rest wants to stay at rest, and an object in motion wants to stay in motion.
6. A change in an object's velocity over time. This happens when an object speeds up, slows down, or changes direction.
8. Force The overall, total force acting on an object. It's found by combining all the individual forces. This force determines if and how the object will accelerate.