1. Newton's Three Laws of Motion
4 January 1643 – 31 March 1727

2. Newton's First Law of Motion
An object at rest tends to stay at rest.
An object in motion tends to stay in motion with the same speed and in the same direction unless acted upon by an unbalanced force
Inertia: The tendency of an object to keep moving at the same
speed and in the same direction

3. Newton's First Law of Motion Examples
Car sudden acceleration
The drink , which was at rest, wants to stay at rest.
Possible result : spill

4. Newton's First Law of Motion Examples
Car going 35 miles/hr.
Driver also going 35 miles/hr ( but he does not feel it : they are not moving relative to the car ).
Brisk stop of the car => the driver keeps traveling 35 miles/hr until acted on by an external force : steering wheel, dashboard, windshield.
Hence the importance of the Driver Seat Belt

5. Newton's First Law of Motion Examples
Head resists the motion and moves to the back
rear-end collisions
Hence the importance of the Driver Headrest

6. Newton's First Law of Motion More Examples

7. Newton's Third Law of Motion
For every action there is an equal and opposite re-action.
Democrats
Republicans

8. Newton's Third Law of Motion

9. Newton's Third Law of Motion
Rockets work by pushing exhaust gases out
Opposite force pushing the rocket upward
Thrust force pushing downward
Skateboard example

10. Newton's Second Law of Motion
F = m.a Or a = F/m
F force: the push or pull on an object that in some way affects its motion
m mass: the amount of matter an object has
a acceleration
W Weight: the force which pulls you toward the center of the Earth (or any other body)

11. Newton's Second Law of Motion
Units:
[F] = [M] [a]
[F] = kg m/s2
1 Newton (N)  1 kg m/s2

12. Newton's Second Law of Motion
the harder you hit a baseball, the faster the ball goes a = F/m.
If you substitute the baseball with a more massive ball , ( increasing m ), it will no go far.
It will take the 18 wheels truck longer time to come to stop than the smaller truck …due to their mass differences.

13. Newton's Second Law of MotionIf
Then
No Acceleration  * Object at rest tends to stay at rest
* object in motion tends to stay in motion
with the same speed and in the same direction
Newton’s First Law

14. Newton's Second Law of Motion
Acceleration Due to Gravity
                                    
Gravitational force (weight) is proportional to mass.
Double the mass and the gravitational force will be doubled also.
Ratio of weight to mass is always the same:  g This is explained further, below.
Figure Source :