1 / 21

Describing Motion

Analyzing the Tortoise and Hare race using position-time, velocity-time, and acceleration-time graphs. Determine fastest average velocity and maximum instantaneous speed.

Download Presentation

Describing Motion

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. Describing Motion Position, velocity, and acceleration §2.1–2.4

  2. The Tortoise and the Hare Told in words, formulas, and graphs

  3. Board Work Describe the Tortoise-and-hare race using a position-time graph.

  4. Question Who was fastest? • The tortoise. • The hare. • They had the same speed. • What do you mean by faster?

  5. Dx average velocity = over entire interval Dt Velocity Rate of changing position

  6. Question Who had the fastest average velocity? • The tortoise. • The hare. • Their averagevelocities were the same. • Over what time interval?

  7. Velocity Units distance = m/s time

  8. Velocity as Slope D distance Velocity = = slope of graph! D time distance Dx Dt time

  9. lim Dt0 Instantaneous velocity smaller Dt finite Dt Young and Freedman, Figure 2.7

  10. Instantaneous Velocity Dx instantaneous velocity = lim at one instant Dt Dt 0

  11. Question Who had the fastest maximum instantaneous speed? • The tortoise. • The hare. • Their instantaneousspeeds were the same.

  12. Board Work Describe the Tortoise-and-hare race using a velocity-time graph.

  13. hare tortoise Speeds and Areas speed area = vDt = D(x) t0 t1 t2 t3 t4 time

  14. Board Work A car waits at a stop light for 5 seconds, smoothly accelerates to 15 m/s over 5 seconds, and then continues at 15 m/s. Describe the car’s motion using a speed-time graph.

  15. Dv average acceleration = Dt over the entire interval Dv instantaneous acceleration = lim Dt Dt 0 at one instant Acceleration Rate of changing velocity

  16. Question What is the SIunit for acceleration? • m. • s. • m·s. • m/s. • m2/s. • m/s2. • m2/s2.

  17. Group Board Work In the car scenario: What is the car’s acceleration during the different segments of its motion? Describe the car’s motion using an acceleration-time graph.

  18. Group Work Describe four ways (x-t, v-t, a-t, words): position 0 time

  19. Group Work Describe four ways (x-t, v-t, a-t, words): velocity 0 time

  20. Group Work Describe four ways (x-t, v-t, a-t, words): acceleration 0 time

More Related