1. Demonstration: Egg Drop!
What is the initial motion of the egg?
The egg is at rest.
What causes the egg to change motion?
The force of gravity causes the egg to fall into the cup.
How does this model the law of inertia?
When the tube and pie tin are removed, the egg stays at rest for a split second before gravity acts on it.

2. Demonstration: Egg Drop!
Which objects are put into motion in this demo?
The pie tin, paper towel tube, and egg.
All these objects have inertia.
Which of these objects are easier to move?
What makes these objects easier to move?
The more mass an object has, the more inertia it has, and the more force it will take to change its state of motion
What gives an object more inertia?

3. What is Mass?
Amount of matter in an object (how much “stuff” is in an object)
Mass is the measure of the inertia of an object
SI Units: kilograms (kg)
The more mass an object has, the more inertia it has, and the more force it takes to change its state of motion

4. QUICK NOTE:
In order to get something to move, the force applied must be big enough to overcome the inertia
Ex. If you push a desk with a small force it will not move because the force is not big enough to overcome the inertia of the desk (a desk at rest wants to remain at rest)

5. William “the Refrigerator” Perry vs. a little person
Who has more mass?
Who has more inertia? Why?
William Perry
William Perry because mass is a measure of inertia

6. What is Volume? The amount of 3-dimensional space an object takes up
SI unit: liters (L)

7. Mass is NOT Volume
Which of the following objects has more mass? More volume?

8. What is Weight? The force of gravity on an object
SI units: Newtons (N)
Weight depends on an object’s location!!

9. Mass is NOT Weight Is mass the same on Earth and the moon?
Is weight the same on the Earth and the moon?
What would the units be in this cartoon?

10. What’s the relationship between mass and weight?
Mass and weight are proportional to each other in a given place
weight=(mass x acceleration)
On Earth: weight=mass x 9.8m/s2
Many people approximate so weight=mass x 10

11. Stop and Jot Your car gets towed and crushed. What happens to… Mass:
Inertia:
Volume:
Weight:
Stays the same
Stays the same
Decreases
Stays the same

12. 10 Minute Practice
If the mass of an object is doubled, what will happen to its inertia?
Sally goes on a diet, what happens to her inertia? Why?
Put the following examples in order from greatest inertia to smallest inertia.
55-kg model
80-kg track and field athlete
12-kg dog
150-kg man who eats his feelings
Calculate the weight (in N) of a 2000 kg elephant
Calculate the weight (in N) of a 2.5 kg melon
An apple weighs about 1N on earth. What is its mass (in kg)?
Wrap up question: Explain how weight and mass are different. What is the relationship between the two?