1. PHYSICS MS. MILLINER 2.24.12

2. Warm-Up_S Yesterday we discussed average velocity and instantaneous velocity. Review your notes and answer the following: 1. How can we find average velocity for an interval? 2. How can we find instantaneous velocity for an interval? 3. What is the average velocity for 1-2 s? 3-6 s? 6- 9 s? 4. Find 3 instantaneous velocities for this graph 5. Create a quick sketch of velocity-time graph

3. Warm-Up_H Yesterday we discussed average velocity and instantaneous velocity. Review your notes and answer the following: 1. How can we find average velocity for an interval? 2. How can we find instantaneous velocity for an interval? 3. What is the average velocity for 1-2 s? 3-6 s? 6-9 s? 4. Find 3 instantaneous velocities for this graph 5. Create an average velocity-time graph (in today’s notes) 6. Create an instantaneous velocity-time graph (in today’s notes)

4. Review 2.23.12 You will have 15 minutes to complete the problems from 2.23.12 After that time, we will discuss answers as a class Be prepared to share!

5. Acceleration Lab We will go outside One student at a time will be selected to sprint the 100 ft distance. Pairs of students will stand at each 10 foot marking and record how long it takes the person to reach their position. Each pair will record their data on a whiteboard. We will repeat this exercise with another student. If time allows, we will analyze the data and race a pair of students, making a prediction based on the data collected Ground rules…?

6. What is required to calculate speed? (2 things) How can we improve data collection in the future What would you expect the data for the race between Elijah and Kedrick to look like? (Who should have a faster time? Explain)

7. What is Acceleration…? Mike’s Physics Video

8. What is Acceleration…? Speeding up or slowing down Changes in velocity Is vector  Which means…? Is present when an object changes speed or direction A = ΔV/ΔT

9. Calculating Acceleration_Examples During a soccer competition,Maleah kicks a ball horizontally at an initial speed of 9.32 m/s. Find the ball’s acceleration if it comes to rest after 2.1 s/. The Lamborghini Murcielago can accelerate from 0 to 27.8 m/s (100 km/hr or 62.2 mi/hr) in a time of 3.40 seconds. Determine the acceleration of this car in both m/s/s

10. Clicker Question 1 A Formula One car is a single-seat racing car with an open cockpit and substantial wings located in the front and rear. At high speeds, the aerodynamics of the car help to create a strong downward force which allows the car to brake from 27.8 m/s (100 km/hr or 62.2 mi/hr) to 0 in as small of a distance as 17 meters. Determine the deceleration rate (i.e., acceleration) achieved by such a car.

11. Clicker Question_2 In the Funny Car competition at the Joliet Speedway in Joliet, Illinois in October of 2004, John Force complete the ¼-mile dragster race in a record time of 4.437 seconds. Determine the average speed of the dragster in mi/hr and m/s. GIVEN: (1.000 mi =1609 m)

12. Clicker Question_3 In a track victory, Michael Z, runs 100 m in 10.2 s. Determine his average speed Bonus: What is his acceleration for this time period? Explain how you found your answer

13. Exit Ticket Do you know the difference between speed and velocity? Distance and displacement? In the qualifying round of the 50-yd freestyle in the sectional swimming championship, Dugan got an early lead by finishing the first 25.00 yd in 10.01 seconds. Dugan finished the return leg (25.00 yd distance) in 10.22 seconds. a. Determine Dugan's average speed for the entire race. b. Determine Dugan's average speed for the first 25.00 yd leg of the race. c. Determine Dugan's average velocity for the entire race.