1. Chapter 4: Forces and the Laws of Motion

2.  Misconception: an object with no force will be at rest.  Inertia – the tendency of an object to maintain its state of motion, or tendency not to accelerate.

3.  Acceleration is determined by net external force.  Net external force – to total force from a combination of external forces on an object; sometimes called the resultant force.  Vector sum of all forces acting on an object.

6.  Mass is a measurement of inertia.  Inertia is proportional to mass.

7.  Objects in motion tend to stay in motion.

8.  Equilibrium – the state in which there is no change in a body’s motion.  Occurs when there is no net force on the object. ▪ When the vector sum of all forces acting on an object is equal to zero.