Newton

1
Newtons 1st Law

• Final Review 2003

2
Terms

• Inertia- The resistance an object has to a change
  in its state of motion
• Velocity- Speed in a certain direction
• Mass- The quantity of matter
• Force- A vector quantity, producing motion in the
  direction of its application push or pull
• Equilibrium- When net force is zero

3
The Basic Concepts

• With no net force acting up on it
• - an object at rest tends to stay at rest
• - an object in motion tends to stay in
  motion
• - both objects will continue with same
  inertia and same velocity
• - as mass increases, inertia increases

4
Another Perspective
5
The Real World-A car collision

• LAW OF INERTIA- the natural tendency of an object
  to keep doing what its doing, unless acted on by
  an unbalanced force
• -resist changes in state of motion
• SEATBELTS?

6
The Truck and Ladder

• We experience inertia in vehicles when we brake
  or stop

7
More Examples

• Blood rushing from feet to head when an elevator
  going down stops
• Head-rests in cars to prevent whip-lash
• Falling off a skateboard
• Sliding cloth out from under objects

8
Unbalanced Forces Friction Galileo If
friction was eliminated
9
Inertia and Mass

• More massmore inertia
• Objects in motion eventually stop due to friction
  or other force
• Newton- force causes objects to stop, not move

10
Think about it

• The answer is B
• - It would keep going at a constant speed in
  the same direction due to lack of gravity, air
  resistance, or friction.

• If you were on the moon and you threw a banana
  into space, would the banana A) gradually stop
  due to air resistance or B) continue in motion at
  a constant speed in the same direction?

11
Multiple Choice

• Which has more inertia?
• A) Keiko
• B) Hot air
• balloon
• C) Amazon Parrot
• with a cracker

• The answer is A because Keiko has more mass than
  the other two object, therefore having more
  inertia, or resistance to change in motion.

12
Almost Done

• 1) 1 kg __ Newtons?
• A) 1kg 9.8 N
• 2) Does a 50 lb barbell have twice as much
  inertia and a 25 lb barbell? Mass? Volume?
  Weight?
• A) All answers are YES