1 / 25

Chapter 1

Chapter 1. Motion. Opening Question. How fast am I moving right now? Did you take into account the… plate shifting (1 in/yr) earth rotating (1038 mph) earth orbiting (67000 mph) galaxy spinning (43000 mph) universe expanding. Motion. How do we determine how fast something moves?.

barth
Download Presentation

Chapter 1

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Chapter 1 Motion

  2. Opening Question • How fast am I moving right now? • Did you take into account the… • plate shifting (1 in/yr) • earth rotating (1038 mph) • earth orbiting (67000 mph) • galaxy spinning (43000 mph) • universe expanding

  3. Motion • How do we determine how fast something moves? • Create a reference point because everything moves relative to everything else • All based on your perspective or point of view (POV)

  4. From Your POV • You are in a car on I-5 going exactly 70 mph. How fast is...

  5. Motion • How do we measure “fastness”? • Speed – the rate at which something moves • Rate – how much in a certain amount of time • Ex. mph, kph, or m/s

  6. Rates • Max is thinking about different units that can be used to express the speed of a car on a highway. Which units couldn’t be used to express the speed of a car?

  7. BugattiVeyron Super Sport(Fastest Car in the World)

  8. Motion • What is the difference between instantaneous and average speed? • Inst. is at a specific time and average is over a period of time • Average speed is the distance traveled (displacement) divided by time • Units: m/s or km/hr

  9. Speed (Math Triangle)

  10. BugattiVeyron - Practice • If the car went 2875 m in 25 s, what is its average speed? • If the car was going 115 m/s, how fast can it cover 500 m? • If the car was going 115 m/s how far does it go in 2 s? • Speed = 115 m/s • 258 mph • Time = 4.3 s • 230 m

  11. Speed – Basic Practice • What is the speed of a bike that travels 15 m in 2 s? • If a rabbit is going 3 m/s for 4 s, how far did it go? • How long did it take a koala bear moving at 0.5 m/s to climb a 20 m tree? • 7.5 m/s • 12 m • 40 s

  12. Speed – Advanced Practice • How much time would it take for the sound of thunder to travel 1,500 meters if sound travels at a speed of 330 m/sec? • 4.5 s • How much time would it take for an airplane to reach its destination if it traveled at an average speed of 790 kilometers/hour for a distance of 4,700 kilometers? • 5.9 s • How far can a person run in 15 minutes if he or she runs at an average speed of 16 km/hr? (HINT: Remember to convert minutes to hours.) • 4 km

  13. Speed – Advanced Practice • The speed of light is about 3.00 x 105km/s. It takes approximately 1.28 seconds for light reflected from the moon to reach Earth. What is the average distance from Earth to the moon? • 384000 km • The average distance from the sun to Pluto is approximately 6.10 x 109km. How long does it take light from the sun to reach Pluto? Use the speed of light from the previous question to help you. • 20000 s OR 333.3 min OR 5.6 h

  14. Distance-Time Graphs

  15. Velocity • What is the difference between speed and velocity? • Why is it called a speedometer and not velocitiometer? • Velocity is speed, but with a direction • It does not give you a direction, only a speed • Unless its combined with a compass

  16. Constant • If a car is driving 60 mph in a circle, does it have a constant velocity or speed? • Constant means it doesn’t change • The direction is changing, so it only has constant speed

  17. Constant If a car has a constant velocity of 30 m/s does it have a constant speed? If a car is going a constant speed of 25 m/s does it have a constant velocity? Yes, it will continue going 30 m/s. No, constant speed does not mean the constant direction

  18. Acceleration • Explain what acceleration means and identify which of the following are examples of acceleration.

  19. Motion How can we measure changes in velocity? • Acceleration – the rate at which velocity changes • Has direction (+ or - ) • Units: m/s2 • Acceleration formula • vf = final velocity • vi = initial velocity • t = time

  20. Motion A bike goes from rest to 20 m/s in 5 s, what is the acceleration? A runner going 10 m/s comes to a stop after 5 seconds, what was the acceleration? • 4 m/s2 • Positive = speed up • Same direction as v • Acceleration • -2 m/s2 • Negative = slow down • Opposite direction as v • Acceleration

  21. Motion What is the acceleration when you have a constant velocity? Any velocity minus itself is zero, so the acceleration would be zero

  22. Motion • If a truck at rest goes to 50 m/s in a northerly direction in 10 seconds, what is the truck’s: • Speed? • Velocity? • Acceleration? Speed = 50 m/s Velocity = 50 m/s north Acceleration = 5 m/s2 north

  23. Motion – More Practice • The cheetah, the fastest of land animals, can run a distance of 274 m in 8.65 s at its top speed. What is the cheetah’s top speed? • 31.7 m/s • In 1985, Matt Biondi set a record for the men’s 100 m freestyle even in swimming. It took him 49.17 s to swim the 100 m length of the pool. What was his speed? • 2.0 m/s • While drag racing out of our school parking lot, I time myself at a speed of 40 m/s, which was 7 s after starting. What was my acceleration during this time? • 5.7 m/s2 • A baseball is pitched with a speed of 35 m/s. How long does it take the ball to travel 18.4 m from the pitcher’s mound to home plate? • 0.53 s

  24. Acceleration Review

  25. BugattiVeyron vs. EuroFighter

More Related