1. EXAM NEXT CLASS
All through Day 1 of GT physics.

2. A Reminder Which is the correct for the Y component of this vector?
A) 20 Sin 30
B) 20 Cos 30
C) 30 Sin 20
D) 30 Cos 20

3. YOU AND GOLF BALLS…
I created a free response type prompt to help you understand the ideas of yesterday as well as what to expect.

4. ALONE AT FIRST… PART 1
11 minutes for all 3 is expected from you.

5. OK… Talk over 1-3 with Partners
7 minutes

6. Example of Grading Style
7 points total
A) 2 points: 1 point: For a procedure that could correctly be used to verify the two goals of initial velocity and angle 1 point: For the measurements that needed to be made: Time in air from launch to FIRST impact The height AND horizontal distance from initial point to first impact

7. B) 2 points: 1 point: For correct indication of how the measurements can be used to determine the initial velocity. Must include using the Pythagorean theorem OR tangent of a known angle.
1 point: For correct indication of how the measurements can be used to determine the launch angle. Must include using the Pythagorean theorem OR tangent from the X and Y components of the initial velocity.

8. C: 3 points. 1point: Correct X graphs showing a linear position relationship AND a velocity at a positive value but zero slope.
1 point: Correct Y graphs showing a parabolic arc ending at a lower position than starting AND a velocity with a negative slope starting positive and ending at a larger negative value.
1 point: Correct description for the graphs.

9. NOW TRY.. THE ACTUAL PART 4

10. Part 5… I show

11. DO YOU GET IT?
Max height relationship

12. DO YOU GET IT?
Overshooting….

13. Or in Other Words…lets write V’s at points

14. Highest point: A system minimum velocity because Vy is minimized (at top of arc Vy is 0)
Symmetry: The velocity up at any height going up has = Vx and = but opposite Vy of the same height going down (ignoring…)
So lets turn to the 3 problems that I will teach

17. MAJOR IDEA:
For any object at some height with an initial velocity, changing the angle will not affect the velocity of impact!
In words:

18. 2) A girl throws a rock horizontally with a velocity of 10m/s from a bridge. It falls 20m to the water below. How far does the rock travel horizontally before striking the water?

19. Key Projectile Terms/Strategies
Horizontal initial motion implies:
Separate numbers and values into X and Y to use
Accelerations for X and Y, and time:

20. Lets Try the Misconceptions…