Chapters

Page 7
This text is meant to accompany class discussions. It is not everything there is to know about uniform circular motion. It is meant as a  prep for class. More detailed notes and examples are given in the class notes, presentations, and demonstrations (click here.)

Steps to Solving Projectile Motion Problems

Projectile motion problems are kinematics problems in 2 dimensions. They are not hard, but they are also not short when showing all the steps.

 1 Break up the initial velocity into horizontal and vertical velocities. (Previous page.) 2 Fill out the givens table with as many variables as possible. (Recall that the vertical acceleration is down at 9.80 m/s2 on the Earth. Horizontally the projectile moves at a constant velocity. This means horizontally, the acceleration is zero.) (Previous page.) 3 Use kinematics with only the horizontal givens to solve. Always neglect air resistance. 4 Use kinematics with only the vertical givens to solve. (Keep in mind that time is the ONLY variable that is copied into both columns -because time is a scaler.) 5 When solving for the direction and magnitude of the impact velocity, use trigonometry and geometry to put the impact velocity together.(page 9)

Example 6
 A spear is thrown off of a high ledge with the givens shown in the picture to the right. What is the spear's location after 3.00 seconds? (Neglect the height of the person throwing the spear.)
Solution
 Here is a YouTube video of the solution shown below, http://youtu.be/K7tQcO2TwxQ. It will open in a new window.

by Tony Wayne ...(If you are a teacher, please feel free to use these resources in your teaching.)