1. Speed, Velocity, and Acceleration

2. Speed - Review Measurement of distance traveled per unit of time Measurement of distance traveled per unit of time  speed = distance / time (s=d/t)  distance = speed x time (d=st)  time = distance / speed (t=d/s) Cockroach 1.25 m/s Kangaroo 7 m/s Car down the highway 30 m/s Sound (in air) 343 m/s Space Shuttle 8,000 m/s Light 300,000,000 m/s Comparison Speeds SpeedTime

3. Distance and Displacement Distance – measure how far actually traveled Distance – measure how far actually traveled – “How far is it to your house? Or How far is it between Dallas and Houston?” (If you had to walk it…) Displacement – straight line distance from start to finish in a specific direction Displacement – straight line distance from start to finish in a specific direction –THE SHORTEST PATH

4. Velocity Velocity is speed in a specific direction. Velocity is speed in a specific direction.  V = D / t + direction ~ Two birds leave the same tree at the same time. ~ One bird flies 10 km/h East for 1 hour, 15km/h South for 30 minutes, and 5 km/h West for 1 hour.One bird flies 10 km/h East for 1 hour, 15km/h South for 30 minutes, and 5 km/h West for 1 hour. The second bird flies 10 km/h North for 1 hour, 15km/h, 15 km/h West for 30 minutes, and 5 km/h South for 1 hour.The second bird flies 10 km/h North for 1 hour, 15km/h, 15 km/h West for 30 minutes, and 5 km/h South for 1 hour. Why don’t they end up at the same destination?Why don’t they end up at the same destination? Velocity changes as your speed or direction changes!

5. Example: These cars are traveling at similar speeds but their velocities are different. Why?

6. In 10 words or less… Tell your partner the difference between speed and velocity. Tell your partner the difference between speed and velocity. Brainstorm What are the three different ways your car can accelerate?

7. Acceleration – Change in motion Changing direction Changing direction –Turning a corner, making a U-turn Speeding up Speeding up – positive acceleration Slowing down Slowing down –negative acceleration

8. How are speed, velocity, and acceleration related? Example of Acceleration How Velocity Changes A plane taking off A car stopping at a stop sign Jogging on a winding trail A dog chasing its tail Riding on a rollercoaster

9. Self Check: Which of the following are examples of velocity? A. 25 m/s forward B. 1500 km/h C. 55 m/h South D. All of the above 25 m/s forward 55 m/h South

10. A car is sitting at a stop light. The light turns green and the car moves forward. As it approaches the corner, it does not slow down but does turn right. The car continues driving down the street until it reaches its destination, then it stops. A car is sitting at a stop light. The light turns green and the car moves forward. As it approaches the corner, it does not slow down but does turn right. The car continues driving down the street until it reaches its destination, then it stops. Read the scenario below. With your partner, list all the different examples in which the car changes velocity.

11. A paper airplane is traveling towards a student. The airplane travels 10 meters in 2 seconds before hitting the student. What is the velocity of the plane? A. 5 m/s B. 0.5 m/s C. 5 m/s toward the student D. 0.5 m/s toward the student 5 m/s toward the student