Download 8th Grade Physical Science

8th Grade Physical Science
Chapter Two Vocabulary
1. Motion – change in position relative to a reference point
2. Frame of Reference – the background used to compare motion
3. Distance – how far something has moved
4. Displacement – the distance and direction of the change in position from a
starting point
5. Speed – distance traveled in a given amount of time
s = d/t
6. Constant Speed – speed that does not change during the interval
7. Average Speed – total distance traveled divided by the total time it takes
8. Instantaneous Speed – speed at any given point in time
9. Velocity – speed in a given direction
10. Acceleration – change in velocity; change in the speed and or direction of an
object’s motion
a = Vf – Vi / t
11. Force – a push or pull on an object
12. Net Force – the combination of all forces on an object (forces in the same
direction add, forces in opposite directions subtract), a net force on an object will
change its motion
13. Balanced Forces – equal forces in opposite directions cancel or are balanced,
there is no net force and no change in motion
14. Inertia – the tendency of an object to resist changes in its motion, increases with
mass