Collision Course: Elastic and Inelastic Collisions Corina Bot, PhD (NJIT, C 2 PRISM) Keri Salvador (NJIT, C 2 PRISM) Caroline Savio (ESHS, NPS) Career Day May 11 th, 2010

Outline of Presentation About Collision Course Applet Lesson Plan in Conjunction with Applet Conclusion and Questions

Concepts Behind Collision Course Applet Used to distinguish elastic and inelastic collisions Conservation of momentum

momentum before collision = momentum after collision results before = results after Elastic collision Conservation of momentum

momentum before collision = momentum after collision Inelastic collision Conservation of momentum results before = results after

Introduction to Collision Course Applet Designed by C 2 PRISM Fellow Corina Bot, PhD.  Dr. Bot interviewed six Advanced Placement Physics students at once via focus-group. Students really liked the idea of acquiring a physics concept shaped as a game.

Features of Collision Course Applet Multiple choice question game Takes place in neutral setting Player chooses which car to drive Contains sound effects Visible damage in the cars after collisions Cartoon policeman assigns ticket at collision scene  Player must distinguish whether collision was elastic or inelastic  A correct answer -> policeman gives you points and your ticket is void  An incorrect answer -> policeman gives you a ticket and you lose points

Specifics on Applet Creation Java applet developed by software engineer students at NJIT Flash software/plug-in required PC and Mac OS Compatible

Outline of Presentation Lesson Plan in Conjunction with Applet

Engagement and Assessment Ideally, students work independently on applet using computers in lab classroom.  If there are not enough computers in classroom, work in pairs.  Or perform applet in computer lab instead of physics lab. Formative Check  The applet consists of multiple choice questions that evaluate the student’s understanding of types of collisions.

Lesson Plan in Conjunction with Applet Some practice problems  Mario and Luigi on Bumper Cars The physics classroom  fm fm

Elastic collision Input: m 1 = 300 kg m 2 = 400 kg v 1i = 20 km/h v 2i = 0 km/h Calculate: v 1f =? v 2f = ? Momentum is conserved!

Solution Substitute values given in problem into equation (1): Substitute values given in problem into equation (2): Substitute equation (4) in equation (3): Inputs: m 1 = 300 kg m 2 = 400 kg v 1i = 20 km/h v 2i = 0 km/h Calculate: v 1f =? v 2f = ?

Inelastic collision Input: m 1 = 300 kg m 2 = 400 kg v 1i = 20 km/h v 2i = 0 km/h Calculate: v f = ? Calculate: momentum before & after collision Momentum is conserved!

Solution momentum before collision = momentum after collision Inputs: m 1 = 300 kg m 2 = 400 kg v 1i = 20 km/h v 2i = 0 km/h Calculate: v f =?

Conclusions Many senses engaged in learning process Group discussion with class Group instruction with visual demonstration Independent work on applet and on practice problems Paired work (optional) Students will qualitatively and quantitatively distinguish elastic from inelastic collisions.

Questions? Thank You!