Chapter Five Inertia

An object moving with a constant force moves with constant acceleration.

Force is considered an independent variable because it is the variable that is controlled and it goes on the x-axis.

Acceleration is considered the dependent variable because it changes based on force, so it goes on the y-axis.

The interaction between force and acceleration is proportional because its graph is a straight line. An example of non-proportional would be?

Resisting a change in velocity is called inertia or Newton’s First Law.

Example: The graph shows an acceleration vs. force graph for three objects. The mass of object 2 is 0.20kg. What are the masses of objects 1 and 2?

If multiple forces are acting on an object because of the F=ma equation Force is really the net force.

The standard unit for force is the Newton Newton’s Laws are always written from the perspective of the object.

Mechanical Equilibrium: Fnet=0 Static Equilibrium: Object at rest Dynamic Equilibrium: Object moving in a straight line with constant velocity. For example an ice skater on frictionless ice.

“..no cause is needed for an object to move!” This means that an objects natural state (rest or motion) is considered to be uniform.

F=ma is Newton’s second law. This law describes how an object will respond to forces identified by Law 1.

Example 5.5 and 5.6:

Which of the following free-body diagrams shows an elevator moving upward and slowing to a stop?

COMPLETE THE FOLLOWING: Page 147 conceptual 4, 7 and 15 Page 148-150 exercises 13,14,21,22,31, 33,53 and 55