DO NOW CLEAN UP EVERYBODY EVERYWHERE CLEAN UP EVERYBODY DO YOUR SHARE

On the back of the sticky note that I give you, write down a question on any topic from chapters 1 through 5 (we are in chapter 6 now). The question can be long or short and require a word or math answer. Write on the front of the sticky note a 1 if your question is easy, 2 if it’s average, and 3 if it’s hard.

Get into groups of 4 or 5. Gather your notes and a calculator.

Week Agenda: Class 1 – return lab reports, conservation of momentum, introduce collisions Class 2 – elastic and inelastic collisions, demonstrations Class 3 – review for test Class 4 – chapter 6 test

Let’s Review! What is momentum? What is the conservation of energy? What is Newton’s 3 rd law? So, what is the conservation of momentum?the conservation of momentum

Conservation of Momentum ~ the total momentum of all objects interacting with one another remains constant ~ (m 1 v 1 + m 2 v 2 ) i = (m 1 v 1 + m 2 v 2 ) f ~ change in momentum of object one equals the opposite change in momentum of object two (Newton’s 3 rd law) ~ (m 1 v 1 ) f – (m 1 v 1 ) i = –(m 2 v 2 ) f – (m 2 v 2 ) i

In the game of pool, the cue ball collides with colored billiard balls. The mass of all billiard balls is 160 grams. Pretend a billiard stick hits the cue ball and causes it to move 4.50 meters per second. Then, the cue ball hits the green ball that is resting on the pool table. If the velocity of the cue ball is meters per second after the collision, what is the velocity of the green ball after the collision? How does the game of pool relate to the conservation of momentum?

Homework Practice D Page 209 # 1 Section Review Page 211 # 3

Week Agenda: Class 1 – return lab reports, conservation of momentum, introduce collisions Class 2 – elastic and inelastic collisions, demonstrations Class 3 – review for test Class 4 – chapter 6 test

AGENDA 1)Go over homework 2)Take notes 3)Demonstrate collisions!

Inelastic Collision ~ a collision in which two objects deform in a collision and move separately ~ (m 1 v 1 + m 2 v 2 ) i = (m 1 v 1 + m 2 v 2 ) f ~ p IS conserved ~ KE is NOT conserved

Perfectly Inelastic Collision ~ a collision in which two objects stick together after colliding ~ (m 1 v 1 + m 2 v 2 ) i = (m 1 + m 2 )v f ~ p IS conserved ~ KE is NOT conserved

Elastic Collision ~ a collision in which two objects move separately after colliding ~ (m 1 v 1 + m 2 v 2 ) i = (m 1 v 1 + m 2 v 2 ) f ~ p IS conserved ~ KE IS conserved

How many perfectly inelastic collisions do you see? How many elastic collisions do you see?

Homework What are two examples* of perfectly inelastic collisions? What are two examples* of inelastic collisions? What are two examples* of elastic collisions? * not discussed in class

Week Agenda: Class 1 – return lab reports, conservation of momentum, introduce collisions Class 2 – elastic and inelastic collisions, demonstrations Class 3 – review for test Class 4 – chapter 6 test

Kelvin and Richard are racing on Roosevelt Boulevard. Kelvin is going 102 mph and Richard is going 3 mph slower. The mass of Kelvin and his car is 700 kg and Richard and his car are ¾ that mass. If they both press the brakes with 15,000 N, how long does it take them each to stop? 1 mi = 1,609 m

In the game of pool, the cue ball collides with colored billiard balls. The mass of the cue balls is 170 grams and the mass of the yellow ball is 160 grams. Pretend a billiard stick hits the cue ball and causes it to move 5.40 meters per second. Then, the cue ball hits the yellow ball that is resting on the pool table. If the velocity of the cue ball is meters per second after the collision, what is the velocity of the yellow ball after the collision?

Create a question about… momentum and/or impulse (1 st row) conservation of momentum (2 nd row) collisions (3 rd row) equations (4 th row) (I’ll review math questions)