Review Concepts

Exam III

Chapters 2, 3, 4, and 5

Inertia - The sluggishness or apparent resistance on object offers to changes in it state of motion.

Speed - The distance traveled per time.


Velocity - The speed of an object and specification of its direction of motion.


If the acceleration is constant for an object, then …


Acceleration - The rate at which velocity changes with time; the change in velocity may be in magnitude or direction or both.


Free Fall - A state of fall free from air resistance and other forces except gravity.

During free fall….

acceleration = g = 9.8 m/s2

velocity = v = g t (5)


Newton's First Law - an object will remain at rest, or in uniform motion in a straight line, unless acted upon by a force.

Newton's Second Law - the acceleration of an object is given by

Newton's Third Law - For every action there is an equal and opposite reaction.

Mass - The quantity of matter in an object. It is the measurement of the inertia or sluggishness that an object exhibits in response to any effort made to start it, stop it, or changes in any way its state of motion.

Weight - The force due to gravity on an object.

Kilogram - A fundamental unit of mass (symbol kg).

Newton - A unit of force. One Newton (symbol N) is the force that will give an object of mass 1 kg an acceleration of 1 m/s2.

Force - Any influence that can cause an object to be accelerated; measured in Newtons in the metric system and pounds in the British system.

Mechanical equilibrium - The state of an object for which all forces cancel to zero and no acceleration occurs.

Friction - The resistive forces that arise to oppose the motion of an object.

Terminal Velocity - The speed at which the acceleration of a falling object terminates because friction balances the weight.

Vector quantity - A quantity that has both magnitude and direction. Examples of vector quantities are force, velocity, and acceleration.

Scalar quantity - A quantity that has magnitude, but not direction. Examples of scalar quantities are mass and speed.

Vector - An arrow drawn to scale used to represent a vector quantity.

Resultant - The net result of a combination of two or more vectors.

Projectile - Any object that is projected by some for and continues in motion by virtue of its own inertia.

Parabola - The curved path followed by a projectile under the influence of gravitational attraction only.

How to Study

1. Review homework questions. Take the practice exam.

2. Review the Summary of Terms section at the end of each chapter.

2. Review the questions in blue throughout the chapters.

3. Study each picture in the chapters and read their captions.

4. Reread the chapters.

5. More advice.