1. The Kinematics Equations (1D Equations of Motion)
Unit 2 Class Notes
The Kinematics Equations (1D Equations of Motion)
Honors Physics

2. Day 7
Review for test

3. Write Down What You Have (Look for “Key” Words)
Step #1
Write Down What You Have (Look for “Key” Words)

4. “Coming to a stop” “Starting from rest” “Coasting” “Maximum Height” “Dropped”
v2 = 0
v1 = 0
v1 = v2 = constant
v2 = 0
a = -9.8 m/s2

5. “Slowing Down” “Braking” “Speeding up” “Accelerating from rest”

6. Make sure your answer makes sense
Step #3
Solve the Equation
Step #4
Make sure your answer makes sense

7. Some Helpful Tips From the Master

8. Choose your “Key Points” in every problem…and do so wisely.
Helpful Tip #1
Choose your “Key Points” in every problem…and do so wisely.

9. “Free-fall” “Throw up”
Vertical Problems
“Throw-downs”
“Free-fall” “Throw up” 1
v1 = 0 1
v1 0 2 2 2
v2 = 0 (at top) 1

10. “Throw up / Come Down” (throw and catch at same height)
Vertical Problems
“Throw up / Come Down” (throw and catch at same height) 2
v2 = 0 (at top)
Dt12=Dt23
v1 = -v3 1 3

11. “Throw up / Come Down” (throw and catch at different heights)
Use and solve quadratically for “t” 2 1 3 2 1 3
Dx13 = +
Dx13 = -

12. Assign positive and negative to different directions.
Helpful Tip #2
Assign positive and negative to different directions.

13. When solving a quadratic equation, do so with minimal effort.
Helpful Tip #3
When solving a quadratic equation, do so with minimal effort.

14. Solving a quadratic equation
Choice A
Choice B
Factoring
Unlikely on a physics problem 
Choice C 
2nd Trace  Zero
(on graphing calculator)

15. Helpful Tip #4
Get out of the habit of trying to use “Chris Farley” when “Leonardo” is necessary.

16. d = rt (Can be used only at constant speed)
Can be used at constant speeds (a=0) or when accelerating. Awesome Dude!

17. Helpful Tip #5
When dealing with a chase problem, use “New-Look” Leo (built for the chase)

18. Chase Problems
Since the two objects (A and B) end up at the same position by the end of the chase, use …

19. It’s already accounted for here and here 
But what if…
The objects start at different places?
It’s already accounted for here and here 

20. But what if… The objects start at different TIMES?
You’ll need to use an extra equation relating the two times. Plug this new equation into the long equation above.
Example: tA = tB + 1

21. Helpful Tip #6
It is always important to remember that when something is thrown up or down (or simply falls), the acceleration at ALL times is constant.

22. The acceleration of the ball at EVERY point on this red path (When it’s rising up, when it’s stopped, when it’s falling down) is always -9.8 m/s2. + -

23. An object thrown up has a constant acceleration at ALL times….
….the acceleration due to gravity x
Objects rise and fall in the same amount of time (assuming no parachute ) t v t
Constant slope = constant accel.

24. Your training is complete
Your training is complete. Now go, have some hot tea, and rest for the upcoming Unit 2 Test

25. Complete Review Worksheet
TONIGHTS HW
Complete Review Worksheet