Common Exam 2

• Common Exam 2• Material includes Week 5-8 (Applying Newton’s

Laws through Linear Momentum and Collisions)• Momentum and Collisions (this weeks material)

WILL BE on the exam.

Review Session for Common exam

Please indicate your preferred time for an OPTIONAL review session:

A)Nov 1st Friday 10-11:30 amB)Nov 1st Friday 1-2:30pmC)Oct 31st Thursday 11:30-1pmD)Oct 31st Thursday 2:30-4pm

What seems wrong with the “physics”?

http://www.lghs.net/ourpages/users/dburns/RRPhysics/Road_Runner_Physics/Movie_files/SpringPunch.mov

http://www.lghs.net/ourpages/users/dburns/RRPhysics/Road_Runner_Physics/Movie_files/HumanCannonball.mov

Iclicker Question #1

Which of the following billiard shots will most likely result in a scratch (white ball is Cue ball)?

A) orangeB) yellowC) blueD) redE) None of the shots are in danger of scratching

Iclicker Question #2

Your friend throws you a baseball to catch. She also throws you a bowling ball which is 10 times the mass of a baseball. The bowling ball will be thrown to you with either (1) the same speed (2) the same momentum or (3) the same kinetic energy as the baseball. Rank these choices of throws of the bowling ball from easiest to hardest to catch.

A) 1, 2, 3B) 3, 2, 1C) 2, 3, 1D) 3, 2, 1E) None of the above

Speed of golf ball from Tee shot

http://www.youtube.com/watch?v=2Y57pw_iWlk

Note compression of ball !

Golf ball hit by Tiger Woods travels at 196 mph which is 87m/s.

Time of impact about 0.5ms.

Completely Inelastic collision

http://www.youtube.com/watch?v=NN_wwbx6Bew

Note: colliding objects stick together

Even though Objects rotating after collision, linear momentum still conserved.

ANGULAR moment (we will have this in a few weeks) also conserved.

Iclicker Question #3

For 2-D ELASTIC collisions, which of the following statements is FALSE

A) The total kinetic energy is conservedB) The total magnitude of the momentum is conservedC) The total momentum is conservedD) The angle at which the colliding masses move away from each

other after the collision depends on the value of the massesE) The angle at which the colliding masses move away from each

other after the collision depends on impact parameter b in the figure.

BeforeAfter

Iclicker Question #4

Which location indicates the approximate center of mass of the 2-D object?

A) AB) BC) CD) DE) E

A

B

C

D

E

Iclicker Question #4

Which location indicates the approximate center of mass of the 2-D object?

A) AB) BC) CD) DE) None of the above

Even after explosion of firework, center of mass follows parabolic path

Is momentum conserved?

http://www.lghs.net/ourpages/users/dburns/RRPhysics/Road_Runner_Physics/Movie_files/GiantRubberBand.mov