1. Learning Target: SWBAT solve problems using momentum and impulse
4/28/2017
Learning Target: SWBAT solve problems using momentum and impulse
For the same force, why is the speed of a cannonball greater when shot from a cannon with a longer barrel?

2. Momentum Momentum is often called… Momentum equation
Inertia in motion
Momentum equation
What is the momentum of a stationary object?

3. Momentum
Example What is the momentum of a 1000kg car traveling with a velocity of 15 m/s?

4. Impulse Definition – Equation – Example
What is the Impulse of a cannonball with a force of 50N applied to it for 1.5 sec?

5. “change in momentum” Impulse-Momentum TheoremSo =

6. Back to the Cannons F Dt = m Dv
The longer cannon barrel gives the cannon ball a larger impulse and therefore more momentum. The Force (F) is allowed to act for a longer time Dt to build up velocity (Dv).

7. Concept Check
Whenever an interaction occurs in a system, forces occur in equal and opposite pairs. Which of the following do not always occur in equal and opposite pairs?
a) Impulses.
b) Accelerations.
c) Momentum changes.
d) But all of these occur in Equal and opposite pairs.
e) None of these do.

8. Concept Check
A 2200kg SUV traveling at 26m/s can be stopped in 21 s by gently applying brakes. What average force is exerted on the SUV in each of these stops?
Draw a picture
Knowns
Unknown
Calculations

9. It sure is tough to get momentum when your velocity is constantly 0!
Assignment
It sure is tough to get momentum when your velocity is constantly 0!
Read Section 9.1
Practice Problems
Pg – 6
Section Review Pg

10. 4/28/2017
Learning Target: Students will be able to apply momentum toward lab situations
A hockey puck with a mass of .115kg is hit with a constant force of 30.0N for 0.16s. What is the impulse given to the puck? With what speed does it head toward the goal?

11. Momentum Groups 1-4 Groups 5-8 Momentum Lab (track)
Impulse & momentum Worksheet
All Parts
Read Section 9.2 when done
Analysis
1 extension

12. Today’s Activities Explosion Lab Skateboard Fun Lab
Dynamics Cart
Be Careful Please
Skateboard Fun Lab
Skateboards & Rope
Do Not Jerk your partner off the board!
Concept Review Problems for 9.1
Due Tomorrow

13. Learning Target: SWBAT describe & apply conservation of momentum
4/28/2017
Learning Target: SWBAT describe & apply conservation of momentum
A car crashes into a tree at 25 m/s and is brought to rest in 0.1 s. Calculate the average force exerted on a 75-kg test dummy by the seat belt.

14. Momentum Groups 1-4 Groups 5-8 Momentum Lab (track)
Impulse & momentum Worksheet
All Parts
Read Section 9.2 when done
Analysis
1 extension

15. Learning Target: SWBAT describe & apply conservation of momentum
4/28/2017
Learning Target: SWBAT describe & apply conservation of momentum
There is a head on crash on the freeway, car 1 is 1500kg and moving at 20m/s. Car 2 is 1000kg and moving at 30m/s, what is the total momentum before the collision? Do we know the total momentum after the collision?

16. Conservation of Momentum
Momentum is a conserved quantity, that is, for any isolated system, the total momentum remains unchanged.
Equation Reminder
Momentum
P = m v
Impulse
F*t & mΔV
Impulse Momentum Theorem
F*t = mΔV

17. Collisions = Two Types of Collisions
Momentum is conserved in Collisions Before Collision After Collision Net Momentum Net Momentum =
Two Types of Collisions
Elastic Collision Inelastic Collision
Bouncing Occurs Objects “Stick” Together

18. Draw an example of each type of collision Elastic Inelastic
Collisions
Draw an example of each type of collision Elastic Inelastic

19. Jocko, who has a mass of 60kg and stands at rest on ice, catches a 20kg ball that is thrown to him at 10km/h. How fast do Jocko and the ball move across the ice?
Example

20. Solving Collision Problems
Elastic Collisions
Object 1
Mass =
Velocity =
Momentum=
Object 1
Mass =
Velocity =
Momentum=
Total Momentum Before
Total Momentum After
Object 2
Mass =
Velocity =
Momentum=
Object 2
Mass =
Velocity =
Momentum=

21. Solving Collision Problems
Inelastic Collisions
Object 1
Mass =
Velocity =
Momentum=
Total Momentum Before
Total Momentum After
Object 1 & 2
Mass =
Velocity =
Momentum=
Object 2
Mass =
Velocity =
Momentum=

22. Collision Practice
Maps For Collision Problems Example 1 Bobby, (50kg) stands at rest on ice, he catches a 25kg log that is thrown to him at 5m/s. How fast do Bobby and the log move across the ice? Example 2 Pool ball #4 (1kg) traveling at 5m/s hits the eight ball which is currently traveling the same direction at 2m/s. The two bounce off of each other, if the #4 ball now has a velocity of 1m/s what is the velocity of the 8 ball?

23. Collision Practice
Example 1 Bobby, (50kg) stands at rest on ice, he catches a 25kg log that is thrown to him at 5m/s. How fast do Bobby and the log move across the ice?

24. Collision Practice
Example 2 Pool ball #4 (1kg) traveling at 5m/s hits the eight ball which is currently traveling the same direction at 2m/s. The two bounce off of each other, if the #4 ball now has a velocity of 1m/s what is the velocity of the 8 ball?

25. I’m about to experience this lesson first hand. OHH NOO!
Assignments
I’m about to experience this lesson first hand. OHH NOO!
Section 9.2
PP 7 – 16 & Section Review

26. 4/28/2017
Learning Target: Students will review concepts of 2-d motion, and momentum
The hot wheels ramp is set up as shown. The two cars are set to leave the ramp at an angle of 45˚with a velocity of 1.5 m/s. How far apart should the ramps be? What will be the momentum of each car as they hit? (m=25g)

27. Coming up Trebuchet Work, Power & Energy Unit Today
Materials list – Wed.
Work Night
Nov. 29th
Work, Power & Energy Unit
Starts tomorrow
Today
Dust off your brain

28. Review Projectile Motion Momentum Assignment Kinematics equations
Solve for y, then x direction
Link with time
Momentum
Impulse theorem F*t = Δp
Collisions Pbefore = Pafter
Assignment
Projectile Motion & Momentum Review Worksheet