1. Test Review

2. Newton’s First Law Newton’s First Law of Motion
An object at rest will remain at rest and an object in motion will continue moving at a constant velocity unless acted upon by a net force.

3. Motion Distance describes how far an object has moved.
Displacement is the distance and direction of an object's change in position from a reference point.

4. Motion Motion Change in position in relation to a reference point.

5. s d t Speed & Velocity Speed rate of motion
distance traveled per unit time

6. Speed & Velocity Instantaneous Speed Average Speed
speed at a given instant like on a speedometer
Average Speed
the total distance traveled divided by the total time of travel

7. t a Acceleration Acceleration a: acceleration vf: final velocity
vf - vi t
Acceleration
Acceleration
the rate of change of velocity
change in speed or direction
a: acceleration
vf: final velocity
vi: initial velocity
t: time

8. Speed & Velocity Velocity speed in a given direction
can change even when the speed is constant!
3 m/s north is an example

9. Speed & Velocity Problem:
A storm is 10 km away and is moving at a speed of 60 km/h. Should you be worried?
It depends on the storm’s direction!

10. Acceleration, Speed and Velocity
Acceleration is the rate of change of velocity.
Acceleration occurs when an object changes its speed, it's direction, or both.
A change in velocity can be a change in speed or direction.

11. Acceleration Positive acceleration “speeding up” Negative acceleration
“slowing down”

12. Newton’s First Law Newton’s First Law of Motion “Law of Inertia”
tendency of an object to resist any change in its motion
increases as mass increases, decreases as mass decreases

13. Graphing Motion speed slope = steeper slope =*
07/16/96
Graphing Motion
speed
Distance-Time Graph A B
slope =
steeper slope =
Straight (horizontal) line =
flat line =
Single point = instantaneous speed
faster speed
no motion
constant speed *

14. Force Fkick Fgrav Force a push or pull that one body exerts on another
What forces are being exerted on the football?
Fkick
Fgrav

15. Force Fnet Ffriction Fpull N W Net Force
unbalanced forces that are not opposite and equal
velocity changes (object accelerates)
Fnet
Ffriction
Fpull N W

16. Force
Balanced Forces
forces acting on an object that are opposite in direction and equal in size
no change in velocity
Net force of 0

17. Balanced Forces
When two or more forces act on an object at the same time, the forces combine to form the net force
The net force on the box is zero because the two forces cancel each other.
Forces on an object that are equal in size and opposite in direction are called balanced forces.