# Momentum Image: http://insidethecosmiccube.blogspot.com/2008/01/whats-story-mourning-glory.html

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• MomentumImage: http://insidethecosmiccube.blogspot.com/2008/01/whats-story-mourning-glory.html

• Vocabulary Sheets DueSept. 24

• MondaySept. 8

• Momentump = mvp = momentum (kgm/s)m = mass (kilograms, kg)v = velocity (meters/second, m/s)Momentum = amount of motionExample:A superhero of mass 75 kg is moving at 65 m/s.

Find the momentum of our man in tights.Find the velocity at which a freight train of mass 200,000 kg has the same momentum.

• ImpulseI = FtI = impulseF = force (Newtons, N)t = change in time (seconds, s)Thanks Mr. NewtonImpulse is change in momentum

• As Seen in Action Comics #13Superman stops a locomotive.

A 200,000kg train is moving at 15 m/s. After Superman flies into it, the train is moving at 0 m/s.

What impulse did Superman deliver to the train?

If Superman and the train were in contact for 2 seconds, what average force did he exert?

What was the average acceleration of the train during its contact with Superman?

• ClassworkPage 193Problems 2-6

• TuesdaySept. 9

• Energy Super HeroesProjects due September 24

You must work at home on these. Theres not enough class time.

This week:1. Super power2. Name & origin story3. List of concepts your hero can demonstrate.

• Energy Super HeroesPresentations start on Sept. 24Format:Slide show & speech VideoPoster presentationOthers?Image: http://www.coverbrowser.com/covers/action-comics

• Rubric: Super Hero ProjectWeek 2

• Superhero Energy ProjectDue Monday, September 15 by email or hard copy in class.From kinetic energy, potential energy, and conservation of energy, write 1 problem at minimum.From thermal energy, thermodynamics, and specific heat, write 1 problem at minimum.From momentum, impulse, and conservation of momentum, write 1 problem at minimum.Looking forward and due on Friday, Sept. 19: From any of the above topics, write 2 additional problems.

• FridaySept. 12

• How Fastv2 = 2ghVelocity squared equals two times acceleration due to gravity times heightNote: How fast doesnt care how heavy.

• ImpulseI = FtI = impulseF = force (Newtons, N)t = change in time (seconds, s)Thanks Mr. NewtonImpulse is change in momentum

• Terminal VelocityThe upper limit of how fast.How fast? Skydiver with a semi-closed parachute: 195 km/h (120 mph)World record human freefall speed is 988 km/h (614 mph)Source: http://en.wikipedia.org/wiki/Terminal_velocityIt happens when your weight is exactly balanced by an upward force called drag.How long? About 15 seconds

• P=mv75kg * 35 m/s > 4875 kgm/sV=p/m4875 kgm/s / 200,000 kg > 0.02 m/sFt = p = mv(f) mv(i) = m(vf vi) = 75kg (0 15 m/s) = -1125 kg m/sFt = p > F = p / t = -1125 kg m/s / 2 s = -562 NF = ma > a = F/m = -562 N / 200,000kg = 0.00281 m2/s2

Image: http://www.coverbrowser.com/covers/action-comics