Essential Understandings for the Projectile Motion Particle Model

Projectile Motion Sim

http://phet.colorado.edu/en/simulation/projectile-motion

Find a pattern for projectiles launched at angles as you vary the launch angle between 70 degrees and 20 degrees above the horizontal.


As a result of working with the sim, be able to report back with...
1.  Something you thought you knew that was confirmed
2.  Something you did not know that you now know
3.  Something that you want to know

PMPM Video Tutorials

Hey gang,
  I'm a little under the weather, so enjoy this video introduction on problem solving with the projectile motion particle model.  This should be enough to help you get started on the projectile problem worksheet I had waiting for you on the cart this morning.  You only need to watch two segments, time 0:00 to 3:00 and time 7:00 to 12:40.  Then you can work on the sheets together/alone with your groupmates.

The angled launch stuff picks up around the 12:30 part of the first video, and then carries into this second video.

Projectile Motion Videos for Analysis

Use Logger Pro Video Analysis to Create Position v. Time and Velocity v. Time graphs for the horizontal and vertical motion of these projectiles.The meterstick for scaling is a 2 (TWO!) meter stick, so use that information accordingly....   You will need to find the slopes for any linear graphs (don't pretend to be taking the slope of a curve).  The motion is interesting once it leaves the hand of the thrower until just before it reaches the target/catcher.  Use the frame advance button to skip forward to the interesting part of the motion.

MIT
https://dl.dropboxusercontent.com/u/33008683/BallToss/Toss1.AVI

Cal Tech
https://dl.dropboxusercontent.com/u/33008683/BallToss/Toss2.AVI

Berkeley
https://dl.dropboxusercontent.com/u/33008683/BallToss/Toss3.AVI

Harvard
https://dl.dropboxusercontent.com/u/33008683/BallToss/Toss4.AVI

Princeton
https://dl.dropboxusercontent.com/u/33008683/BallToss/Toss5.AVI


Cornell
https://dl.dropboxusercontent.com/u/33008683/BallToss/Toss6.AVI


University of Illinois Chicago
https://dl.dropboxusercontent.com/u/33008683/BallToss/Toss7.AVI


University of Illinois Champagne Urbana
https://dl.dropboxusercontent.com/u/33008683/BallToss/Toss8.avi

Standford
https://dl.dropboxusercontent.com/u/33008683/BallToss/Toss9.avi

West High
https://dl.dropboxusercontent.com/u/33008683/BallToss/Toss2.AVI


Just in case you've forgotten, here's the how to video for Logger Pro video analysis (for a different model, so your analysis will be different because you need X and Y position graphs and X and Y velocity graphs)...

UBFPM Essential Understandings

Problem Solving with the Velocity Graph

Figuring out as much stuff as possible when you only know acceleration and change in position.

Elevator Conclusions

In the first part of class on Friday, we established Cameron/Huff's Law, "The Fu and acceleration point in the same direction.

In the elevator activity, we drew velocity v. time graphs that made it look like the acceleration would be upwards during part #2 and downwards during part #4.

We then took a closer look at what the FBD and FAD would need to look like for part #2, and settled on either C or D because their FADS had Fu's that point upwards (A and B had FADs that showed balanced forces).

We can analyze the motion of the elevator based on the amount of UnBalanced Force the guy is experiencing.  Given that C and D are the only options with UnBalanced Forces, and they both show an UnBalanced force of 55 lb directed up, they'll both result in the same acceleration for the guy.  We need to use conversion factors to make this problem manageable.  First, since the scale reads 157 pounds when he first steps on it, we can use the knowledge that 1 kg weighs 2.25 lbs to determine that his mass is around 71 kg.  Then, we can use the understanding that 1 lb is roughly 4.5 Newtons in order to determine that the Fu of 55 lb would be 245 Newtons.  Using a=Fu/m we can then find the acceleration by taking the 245 N divided by 71 kg of mass.  The guy is accelerating at 3.45 m/s/s at that point in time.  Use this process as you work through the problems on the worksheet.  Good luck!