Momentum, Impulse, and Collisions

A.S. 2.4.1 – 2.4.6 Due Monday, January 12

Quiz covering Momentum, Impulse, and Collisions on Monday, January 12

Introductory Examples… Work with your table group You will be assigned one of the following of

activities:1. Landing after a ski jump so you do not hurt your knees

2. Catching a water balloon so you do not get wet

3. Catching an egg so you do not get yolk-y

4. Jumping off a lab station without hurting your knees

5. Catching a 90 mph fastball (baseball) without breaking your hand

6. A stunt performer jumping off a three story building without getting hurt

On your whiteboards, explain and illustrate how you would instinctively perform the assigned task. You have 4 minutes. Go!

Time Remaining for Activity:

4:003:553:50

3:453:403:35

3:303:253:20

Time Remaining for Activity:

3:153:103:05

3:002:552:50

2:452:402:35

Time Remaining for Activity:

2:302:252:20

2:152:102:05

2:001:551:50

Time Remaining for Activity:

1:451:401:35

1:301:251:20

1:151:101:05

Time Remaining for Activity:

1:000:550:50

0:450:400:35

0:300:250:20

Time Remaining for Activity:

0:150:100:09

0:080:070:06

0:050:040:03

0:02 0:01

Stop what you’re doing!

Time to share out your creations! One person from each group bring your whiteboard to the front of the room and hold it high!

Are there ANY similarities to the descriptions and/or the illustrations for all the scenarios?

Momentum Used to quantify the motion of a mass

Mathematical definition: Momentum is equivalent to the product of an

object’s mass (in kg) and its velocity (in m·s-1).

Momentum IS a vector quantity

𝑝=𝑚 ∙𝑣

Fun Facts You Should Remember About MOMENTUM!

Momentum calculations must always include velocity, not speed. Direction is VERY important!

Momentum is a vector quantity! It is added just like other vector addition we’ve worked with so far this year.

Units for momentum:

Net forces result in acceleration. Acceleration results in a change in velocity. Therefore, Net forces result in a change in momentum.

Whiteboard problem! A 0.250 kg ball is moving to the right at a velocity of

+7.40 m·s-1 when it strikes a wall and rebounds back in the opposite direction along its original path.What is the ball’s initial momentum?

If its rebound speed is 5.80 m·s-1, what is its change in momentum?

What is its change in kinetic energy?

What is its change in kinetic energy?

Impulse Impulse, by definition, is equivalent to the change in

an object’s momentum

Mathematically: Impulse is the product of the net force applied (in N) and the time through which the force is applied

Impulse-Momentum Theorem:

Impulse acting on an object is equivalent to the change in the object’s momentum

Impulse—video demonstrations

For each demonstration shown and discussed, think about the following:

WHAT was causing the change in momentum?

HOW was the applied force changed?