1. Unit 3: 2-D Motion and Vectors
Physics Fall 2015

2. Agenda 9/29 Turn in Dune Buggy Challenge Labs Intro to Vectors
Nspire Activity
Notes: Vectors
Vector Exit Slip

3. Vectors
We already know that vectors are measurements that tell us magnitude and direction.
We also know how to examine vectors when they are in the x-direction (horizontal) or the y-direction (vertical).
What happens when something is moving at an angle?

4. Vector Addition
We must break down these angular vectors into their x and y components
For example:
R is my angled vector (resultant vector)
V1 is my x-component
V2 is my y component
How should we determine the value of R?

5. Vector Addition
How do we figure out the length of a hypotenuse of a right triangle?
Good old Pythag!!
a2 + b2 = c2
If v1 is 3 meters and v2 is 4 meters, what is the total displacement of the object as it moves the length of R?

6. Vector Addition How do we draw resultant vectors?
Ex: If a person moves 6 meters east and then 8 meters north, what is their total displacement from where they started? + =
6 meters east
10 meters NE
8 meters north

7. Rules to adding Vectors
Be sure to draw your vectors HEAD to TAIL.
If you do not you will end up with the wrong R
Be sure to draw your vectors differently based on their magnitudes (larger magnitude, larger vector). + =
6 meters east
10 meters NE

8. Agenda 9/30
Pirate Pythag
Addition of Vectors PS

9. Agenda 10/1 Addition of Vectors Nspire Check-up Trig for Physics
Get a hat!!
Trig for Physics
SohCahToa for angled vectors
The PUKE Method
Quiz Friday: Vector Addition

10. Angled Vectors
For vectors that are not completely in the x or y direction, we must use trig!!
Trig will allow us to “break up” an angled vector into its x and y components.
We should probably review some trig!

12. Example Problem b = 8m α = 35o
Find the remaining variables of the triangle.

13. Y- component
X- component

14. Example Problem
A person is looking up at a plane with an angle of 50o , using his range finder he finds out that this plane is 1200m from him. What is the plane’s height above the ground?

15. Agenda 10/5 Collect Take-Home Quizzes Notes: Half-Projectiles
Breaking motion into components
Problem Set: Half-Projectiles
HW: Complete PS

16. Rolling Ball Demo
You will roll a ball off of a table and your partner will drop a ball off of a table at the same time.
Predict: Which ball will hit the floor first? Why?
You need someone with a slo-mo camera in your group.

17. How can we explain this?
We need to break the velocity of the ball into its VECTORS
Rolling Ball
Dropped Ball
X-Velocity
Y-Velocity
** The only vector that explains falling is the Y-Component, which is the same in this demo**

18. Still Don’t Believe Me? Let’s use our equations to prove it.
A ball is dropped from 1m off of the floor with no initial velocity. How long until this ball hits the floor?
A ball is rolled off of a 1m table with initial velocity in the x-direction of 1,000,000,000m/s, but no velocity in the y-direction. How long until the ball hits the ground?

19. The link between the X and Y Directions
The time it takes the ball to fall from the table, is the same amount of time that the ball moves in the horizontal direction. So…
ty = tx

20. Agenda 10/6 Notes/Practice Half-Projectile Problems
Complete HP Problems in Class
HW: Complete Projectile Problems

21. Agenda 10/7 Warm-Up Questions about Half-Projectile HW
Rolling Ball Lab
HW: Complete Rolling Ball Lab

22. Warm-Up
A ball is rolled off of a .75m table with an initial velocity of .5m/s in the horizontal direction. How far away from the table will the ball land?

23. Rolling Ball Lab
It will be your job to predict where the ball will land on the floor.
You will determine the speed of the rolling ball (x-direction)
You will determine how long it will take the ball to fall (y-direction)
You will locate a range on the floor where your ball will land.

24. Agenda 10/8 2nd and 3rd Hour get a HAT Warm-Up
Nspire Quiz: Half-Projectiles
Review of Vector Addition
Putting Problem
Gilligan Problem

25. Go Cubs!!
If Henry throws the ball 400ft to the catcher and the baseball drops a total 2.5m, how hard did Henry throw the ball?

26. Agenda 10/9 Get a Netbook and turn it on now!!
Check Gilligan Problem
Introduce Quarter Project
Video Analysis of Sample Video
What games are you going to try for the project!

27. Agenda 9/13 Let’s Go Outside and PLAY!! We need video cameras
We need any kind of outdoor activity materials

28. Your group should have A video recording device A meter stick
Any supplies necessary to complete your activity.

29. Agenda 10/15 Discuss Quarter 1 Project Intro to FULL Projectiles
PhET
You will need a Netbook and you will work with a partner
When done: Get Nspire and complete Full Projectile questions

30. Agenda 10/16 Notes on Full-Projectiles
PPT and Practice Problems
Complete Practice Packet in Class
Or complete for HW
HW Quiz Monday??
Quarter 1 Project Due: October 29th

31. Full Projectile Shape
The x and y directions are independent of each other still.
Gravity is still the only FORCE acting on the projectile.

32. Half- Projectile Equations
X-Direction Equation(No acceleration)
v = d/t
Can we use this one for vertical motion??
Y-Direction Equations (Acceleration due to Gravity)
g = (vf - vi ) / t
yf = yi + vit +1/2 gt2
vf = vi + gt
vf2 = vi2 + 2gyT
Remember that the link between the two is…
ty = tx

33. New Full-Projectile Equations
All of the half-projectile equations are true, and then some!
tup = tdown
vyi = vyf
v1/2 = 0m/s = vpeak

34. Agenda 10/19 Homework/Notes Check Full-Projectile Example
Complete Full Projectile Problem Set
Quiz Tomorrow:
Trig problems
Half-Projectile Problems
Full-Projectile Problems

35. Homework Quiz At what point is the vertical velocity equal to zero?D B A E
At what point is the vertical velocity equal to zero?
At what points are the horizontal velocities equal?
At what point(s) is the vertical velocity the greatest?

36. Full Projectile Example
A football is kicked with an initial velocity of 15m/s at a 50o angle.
What is the initial vertical velocity?
How long will it take the football to reach its peak height?
What is the initial horizontal velocity?
What is the total range of the football? (horizontal distance)

37. Agenda 10/20 Quiz: Trig, Half and Full Projectiles
Pre-Lab: Full Projectile Challenge Lab
Calculations for Pre Lab
Test Thursday!

38. Agenda 10/21 Warm-Up Full Projectile Challenge Lab Review for Test
Get Nspire and HAT
Full Projectile Challenge Lab
Pre-lab checked by Gustin
Review for Test
T/F Assessment about Projectiles
HW: Study for Test Tomorrow

39. Agenda 10/22
Test on Unit 3

40. Agenda 10/23 Final Work Day IN-CLASS 2nd Hour: Room 217
3rd Hour: In Classroom
5th Hour: Room 259