1. Warm-up 10/16:  1. What’s the difference between distance and displacement?  2. What’s the difference between speed and velocity?  Variables that have an amount AND a direction are called vectors  Variables that only have an amount are called scalars

2. Update Formula Chart:  Put a v (for vector) next to every vector  Put an s (for scalar) next to every scalar  Add 4 equations - I’ll give you the equation, you can fill out the rest later:  d = d 0 + ʋ 0 t + ½ at 2  d = d 0 + ½(ʋ + ʋ 0 )t  ʋ = ʋ 0 + at  ʋ 2 = ʋ 0 2 + 2a(d - d 0 )

3. Notes: Kinematics  Essential question: How do we solve kinematics problems?  Using SKUFWUNA!

4. What is SKUFWUNA?  S – Sketch Draw a picture based on the problem – including ALL info from the problem  K – Known Write down the known amounts given in the problem – include the variable, the amount, and the units  U – Unknown What are you trying to figure out?  F – Formula Pick one from the formula chart.  W – Working Equation Rearrange the equation so that your unknown is by itself on one side  U – Units Plug the units into your working equation so you can make sure you did it right  N – Numbers Plug the numbers into your working equation  A – Answer Write your final answer!

5. Example: Moving Man Problems #2 A man driving a car traveling at 30m/s slams on the brakes and decelerates at 4.75 m/s 2. How far does the car travel before it stops?  S – sketch: v 0 = 30 m/s a = -4.75 m/s 2 d = ? v = 0 m/s (d 0 = 0m)

6.  K – known  (symbol = # units)  ʋ 0 = 30 m/s  a = -4.75 m/s 2  ʋ = 0 m/s  d 0 = 0 m Example: Moving Man Problems #2 A man driving a car traveling at 30m/s slams on the brakes and decelerates at 4.75 m/s 2. How far does the car travel before it stops?

7.  U – Unknown  d = ? Example: Moving Man Problems #2 A man driving a car traveling at 30m/s slams on the brakes and decelerates at 4.75 m/s 2. How far does the car travel before it stops?

8.  F – Formula  Choose an equation from your formula containing the unknown and the knowns  v 2 = v 0 2 + 2a(d – d 0 ) Example: Moving Man Problems #2 A man driving a car traveling at 30m/s slams on the brakes and decelerates at 4.75 m/s 2. How far does the car travel before it stops?

9.  W – working equation  We need an equation that looks like d =  Subtract v 0 2 from both sides: v 2 - v 0 2 = 2a(d – d 0 )  Divide both sides by 2a: (v 2 - v 0 2 )/ 2a = d – d 0  Add d 0 to both sides:  d = (v 2 - v 0 2 )/ 2a + d 0 Example: Moving Man Problems #2 A man driving a car traveling at 30m/s slams on the brakes and decelerates at 4.75 m/s 2. How far does the car travel before it stops?

10.  U - units  Solve your working equation with units only:  d = (v 2 - v 0 2 )/ 2a + d 0  m = (m 2 /s 2 – m 2 /s 2 ) + m m/s 2  m = m + m  m = m (check!) Example: Moving Man Problems #2 A man driving a car traveling at 30m/s slams on the brakes and decelerates at 4.75 m/s 2. How far does the car travel before it stops?

11.  N - numbers  Solve your working equation with numbers:  d = (v 2 - v 0 2 )/ 2a + d 0  d = (0 2 – 30 2 ) + 0 2(-4.75)  d = -900/-9.5  d = 94.74 Example: Moving Man Problems #2 A man driving a car traveling at 30m/s slams on the brakes and decelerates at 4.75 m/s 2. How far does the car travel before it stops?

12.  A - Answer  Write the Number and the Units together:  d = 94.74 m  Use the Moving Man Simulation to check your answer. Example: Moving Man Problems #2 A man driving a car traveling at 30m/s slams on the brakes and decelerates at 4.75 m/s 2. How far does the car travel before it stops?

13. Important!!!  You MUST show each step to get credit for the problem – even if you can do it in your head.  Writing down the answer only will earn you a grade of 13. Out of 100.  (After all, you can get the answer from the phET simulation – I need to know you can figure it out on your own)