Mr. Bouyer

Day 1 | Day 2 | Day 3 - 4 | Lab | Reading Assignment

This Week's

Momentum Inertia	Conservation of momentum	Elastic collision Inelastic collsion

Momentum: the product of the mass of an object and its velocity.

How is momentum different from inertia?

Air Traffic Controller

(25 min) All moving objects have momentum. To calculate momentum, use the equation: Momentum = Mass x Velocity Momentum = M V

Do pendulums of different weightsact the same?

That's nice, but how is a pendulum useful?

Day 2

What is the momentum of a non-moving object?

Conservation of Momentum:

The total momentum of any group of objects remains the same unless acted on by outside forces.

Momentum is also conserved when objects collide.

Momentum after a collision must be the same as before the collision.

This is represented by the equation: M1V1 = M2V2

(25 min)

There are two types of collisions:

• elastic collisions occur when both momentum and kinetic energy are conserved. The colliding objects "bounce" apart. In the real world, perfectly elastic collisions do not occur.

  elastic collision movie clips
  example #1	the colliding objects have the same mass
  example #2	a heavy object collides with a light-weight object
  example #3	a light-weight object collides with a heavy object

• inelastic collisions occur when momentum is conserved, but kinetic energy is not. The colliding objects deform or stick together. In the real world, all collisions are inelastic because some energy is always lost through sound, heat caused by friction or deformation.

  inelastic collision movie clips
  example #4	the colliding objects stick together

  What happenswhen things collide?

Experiment with elastic and inelastic collisions.

Go bungee jumping and try not to hit the ground.

You must know physics to be a good pool player.

The swinging ball apparatus at the top of this page shows that when two balls strike one side, two balls move away from the other side. Use these websites to form a hypothesis for these: What will happen when three balls strike one side? What will happen when four balls strike one side? When everyone at your table has completed today's assignment, ask your teacher for a swinging ball apparatus to test your hypothesis. Were you correct in your hypothesis?

Day 3 - 4

What is the highest point on a rollercoaster?

Momentum plays a major part in most thrill rides, but in none is it more important than rollercoasters. Find out how rollercoasters work.

Explore these websites:

Inventing the Scream Machine
RollerCoaster World
Coaster Gallery
JoyRides
Roller Coaster G-Forces
Amusement Park Physics
The Ultimate Rollercoaster.com
Roller Coaster DataBase

What's the fastest roller coaster in the world?

Roller Coaster Physics Choose From 3 Coasters

Build Your OwnRollercoaster Ride a Rollercoaster

In-class Assignment 214:
This assignment must be turned in by the end of class tomorrow to receive credit.

Pick one of these:

1. Use this essay planning guide to write an essay about roller coasters.
   • Staple a completed essay evaluation rubric to the front of your essay.
   or

2. Use the links above to find 10 roller coasters you would like to ride. Make a PowerPoint slide show of these 10 coasters. Show the following on each slide:
   Use this type of PowerPoint slide:
   • Show a picture of the coaster on the left.
   • Use WordArt to type the Name of the coaster and its Location on the right.

Physical Science

Answer to sample problem:
Momentum = M V
Momentum = (2500kg) (5m/s)
Momentum = 12,500 kg ^. m/s

Momentum is inertia multiplied by velocity.

A non-moving object has a velocity of zero.
Any amount of mass multiplied by zero is zero, therefore the momentum of a non-moving object is zero.

The highest point on a rollercoaster is the top of the first hill.
Because of the conservation of momentum, a rollercoaster can never go higher than that.

However! There are now some coasters that use "magnetic assistance" at places along their tracks that attempt to cheat momentum.