The material on this page will provide you with everything you need in order to be successful with the forces unit.  It cannot be stressed enough how important it is to read the assignments posted here.  Even if you are in class everyday, it will still be hard to grasp all of the material associated with forces.  Forces is a key concept in physics and it is therefore necessary to understand all of the concepts very thoroughly in this unit.  This unit provides you with information that will be necessary to retain throughout all other units in physics.  In other words, it is really, really, really, really, really important that you fully understand the concepts in this unit - really important!


By the end of the forces unit, you should be able to:

  1. Explain what is meant by the term inertia.
  2. Be able to describe the difference between mass and weight.
  3. Define Newton’s second law of motion and be able to explain how a force can cause an object to accelerate.
  4. Calculate the the force, mass or acceleration associated with an object given two variables.
  5. Compare and contrast scalar and vector quantities. Give at least three examples of each.
  6. Explain how various action-reaction force pairs support Newton's 3rd Law of motion.
  7. Be able to design a free body diagram labeling all relevant forces present based on a given scenario.
  8. Be able to determine the direction of an object's travel based on a given free body diagram.
  9. Calulate the net force or acceleration an object will experience based on a given free body diagram.


All of the readings for this unit will be from the physicsclasroom.com website.  This is a phenomenal website that makes difficult concepts much easier to comprehend.  For the forces unit, we will be using the "Newton's Laws" section of the website.  It is highly recommended that you familiarize yourself with this additional resource if you have not already done so for the last unit!  You should have all of the readings finished by the day of the exam.

Lesson 1

Read all material (sections a,b,c,d)

Lesson 2

Read all material (sections a,b,c,d)

Lesson 3

Read sections a,b,c,d,e (skip section f)

Lesson 4

Read all material (sections a,b)

Forces Unit Answer Keys

Forces Packet Answer Key

It is VERY importatnt that you try the problems in the forces packet without looking at the answer key while doing the work. This can give you a false sense that you are understanding the concepts while you may not be truly understanding them.  Use the answer key at your discretion - meaning use it wisely!  Do the practice problems on your own and then look at the answers after you have completed them.  If you are not understanding a concept, it may be useful to work one problem in reverse and then put the answer key away while working others using that problem as an example.