# Force and Motion Vocabulary - 7th Grade

• 1.  Force:  A push or a pull

2.  Motion:  An object's change in position over time when compared with a reference point

3.  Work:  The action that results when a force causes an object to move in the direction of the force.  (work= force/distance)

4.  Power:  The rate at which work is done  (power= work/time)

5.  Joule:  The unit used to express work and energy (newton x meter)

6.  Newton: The unit used to express force

7.  Watt:  The unit used to express power (joules/second)

8.  Reference Point:  An object that appears to stay in place in relation to an object in motion

9.  Acceleration:  The rate at which velocity changes

10.  Velocity:  The speed of an object in a particular direction

11.  Speed:  The rate at which an object moves

12.  Gravity:  A force of attraction between objects that is due to their masses

13.  Inertia:  The tendency of all objects to resist any change in motion

14.  Momentum:  A property of a moving object that depends on the object's mass and velocity

15.  Newton's First Law of Motion:  An object at rest remains at rest and an object in motion remains in motion at constant speed and in a straight line unless acted on by an unbalanced force

16.  Newton's Second Law of Motion:  The acceleration of an object depends on the mass of the object and the amount of force applied

17.  Newton's Third Law of Motion:  Whenever one object exerts a force on a second object, the second object exerts an equal and opposite force on the first