HW: U1 5 (pink) 11/15 U1 7 (salmon) 11/16. Next Test: Friday! PICK UP 1. Papers & calculator TURN IN

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1 U1 PICK UP 1. Papers & calculator TURN IN DO NOW 1. On a half sheet solve using GUESS: If you are displaced 5m behind where you started over a time of 2 seconds. What is your velocity? HW: U1 5 (pink) 11/15 U1 7 (salmon) 11/16 Next Test: Friday!

2 MASTERY QUIZ SOON! Definitions, variables, units, and problems -Distance, d -Displacement, Δd -Velocity, v avg -Acceleration, a -Kinematic Equations

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4 By the end of today, IWBAT -Define and calculate acceleration - Calculate & graph acceleration from v-t graph - Calculate displacement from a v-t graph Why it matters in LIFE: Part of being a functional human being is being able to understand what s happening in the world around you! Why it matters in THIS CLASS: Our Goal = 80% Mastering today s lesson (focused participation, asking questions, etc) is the first brick that will help us reach our goal for this unit, and eventually for the year

5 TEKS: 4(B) describe and analyze motion in one dimension using equations with the concepts of distance, displacement, speed, average velocity, instantaneous velocity, and acceleration; By the end of today, IWBAT -Define and calculate acceleration - Calculate distance and displacement from a velocity-time graph Topic: Acceleration & v-t Graphs

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7 Velocity (m/s) Position (m) LAST CLASS EXAMPLE What was Sadness velocity at time t = 6s? What was her velocity at time t = 9s? Build a velocity-time graph. Time (s) Position (m) Position vs. Time Time (s) Velocity (m/s) Time (s)

8 WHAT IF WE WANT TO KNOW HOW HER VELOCITY IS CHANGING?

9 ACCELERATION, a (Units m/s 2 ) How velocity changes over time. This can be speeding up, slowing down, or changing directions.

10 ACCELERATION, a (Units m/s 2 ) How velocity changes over time. a = v t or a = v f v i t Where: a = acceleration (m/s 2 ) v = velocity (m/s) t = time (s)

11 Velocity (m/s) Position (m) LAST CLASS EXAMPLE What was Sadness acceleration at t =1s? t= 4s? t = 8s? Time (s) Position (m) Position vs. Time Time (s) Velocity (m/s) Time (s)

12 ON A V-T GRAPH = v t v t = a

13 Velocity (m/s) Position (m) LAST CLASS EXAMPLE What was Sadness acceleration at t =1s? t= 4s? t = 8s? Time (s) Position (m) Position vs. Time Time (s) Velocity (m/s) Time (s)

14 EXAMPLE a. What was the acceleration at t = 25s? b. What was her acceleration from t = 10s to t =15s?

15 +v +a -v -a Speeding up! + v - a - v + a Slowing down! *deceleration means that you are slowing down, not necessarily that acceleration is negative

16 EXAMPLE Describe the motion!

17 VELOCITY-TIME GRAPHS Velocity time graphs can also show us distance & displacement! If we take our formula v = d t and solve it for displacement

18 VELOCITY-TIME GRAPHS Graphically Displacement = velocity * time = area under the curve!

19 EXAMPLE a. Find the total displacement. b. Find the total distance c. Find the distance and displacement from t = 2s to t = 10s. Δd = A1 + A2 + A3 + A4 + A5 + A6 Δd = ½(2)(2) + (6)(2) + ½(2)(2) - ½(2)(2) - (2)(2) - ½(2)(2) Δd = 8m

20 VELOCITY-TIME GRAPHS PRACTICE 1. Describe the motion on each segment of the graph. 2. Displacement from t = 2s to t = 4s 3. Velocity at time t = 3.5s 4. Acceleration at t = 1s 5. Total distance and displacement over the entire 6s. 2. Δd = 1(10) + ½(1)(10) = 15m 3. 5m/s 4. a = m = 10/1.5 = 6.67m/s 2 5. d = ½(1.5)(10) + 1(10) + ½(1)(10) + ½(1)(10) + 1(10) = 42.5m Δd = ½(1.5)(10) + 1(10) + ½(1)(10) - ½(1)(10) - 1(10) = 12.5m

21 INDEPENDENT PRACTICE! Procedure for IP time: 1) Silent work time 2) Try and solve without notes first! Hierarchy of who to ask 1) Your brain 2) Your notes 3) Your partner (quiet whisper) 4) Ms. Kelly

22 ACCELERATION, a (Units m/s 2 ) How velocity changes over time. a = v t or a = v f v i t Where: a = acceleration (m/s 2 ) v = velocity (m/s) t = time (s)

23 EXAMPLE Formula Rossa, the fastest steel roller coaster in the world, can go from rest to 240 km/hr in 4.9 seconds. What is its acceleration?

24 NOW YOU TRY A lion starts from rest and reaches a final velocity of 13 m/s in 9 seconds. What is the lion s acceleration?

25 EXAMPLE A car with an initial speed of 23.7 km/s decelerates at a uniform rate of 0.92 km/s 2 for 3.6 s. Find the final speed of the car during this time.

26 INDEPENDENT PRACTICE! Procedure for IP time: 1) Silent work time 2) Try and solve without notes first! Hierarchy of who to ask 1) Your brain 2) Your notes 3) Your partner (quiet whisper) 4) Ms. Kelly

27 EXIT TICKET (5 MIN) 1.Describe the object s motion on each segment of the graph 1. A train. travels on a straight path at 32.0 meters per second. It decelerates uniformly to a speed of 14.0 meters per second in 11.0 seconds. What is the train s acceleration? 2.From rest, a car accelerates to a final velocity of 26 m/s. It takes 2s. What is the car s acceleration? SHOW ALL WORK FOLLOWING THE GUESS METHOD.

28 EXIT TICKET (5 MIN) 1.Describe the object s motion on each segment of the graph 1. A train. travels on a straight path at 32.0 meters per second. It decelerates uniformly to a speed of 14.0 meters per second in 11.0 seconds. What is the train s acceleration? 2.From rest, a car accelerates to a final velocity of 26 m/s. It takes 2s. What is the car s acceleration? 13.0 m/s 2 *No G.U.E.S.S, no credit!