1. Inertia – A property of mass. It is the tendency of an object to resist changes in motion. Force – A push or a pull.

2. Isaac Newton 1665 A.D. Isaac Newtons First Law is the Law of Inertia. It states that an object at rest tends to remain at rest, while an object in motion tends to remain in motion, unless acted upon by an outside force.

3. From the labs: Part I conclusion is that the acceleration is directly proportional to the force. Part II conclusion is that the acceleration is inversely proportional to the mass.

4. Isaac Newton stated this as Acceleration = Force / Mass a = F / m This is known as Isaac Newtons Second Law

5. If a force is a push or pull, then the earth pulling down on an object is the FORCE of gravity. So,…WEIGHT is a force which we can calculate as Weight = Mass * Gravity Example: Weight = 1 kg * 9.8 m/s/s Weight = 9.8 kgm/s/s or 9.8 Newtons We see that weight is a special case of a force: F = m a

6. 1. The dumbbell shown has a mass of 12kg. Find: a) The weight of the dumbbell. b) Allison pushes upward with a force of 120 N. Draw a F.B.D. showing Allisons push and the weight of the dumbbell.

7. What is the resulting acceleration of the dumbbell? d) If Allison pushes up on the dumbbell with a force of 150N, at what rate would the dumbbell accelerate?