1 / 31

Equations of Motion and Accelerated Motion Problem Solving

Learn how to use equations of motion to solve problems related to accelerated motion. Calculate acceleration, average velocity, and distance travelled using the given information. Understand when to run or stop based on traffic light timing.

dianes
Download Presentation

Equations of Motion and Accelerated Motion Problem Solving

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 2 accelerated motion

  2. vocab Systematic error, random error, halt, stationary, initial, final, steadily, apply, uniform, gradient, multiflash, free fall, circuit, magnet, value, scatter, uncertainty, friction, air resistance, twice, stop watch, parabola, angle, throw, projectile, vertical, horizontal, separately, resolve, cosine, sine, tangent,

  3. V t graph 0 velocity is constant, zero, positive, negative, or changing ? acceleration is constant, zero, positive, negative, or changing ?

  4. V t graph decreasing and negative constant 0 velocity is constant, zero, increasing, decreasing or negative? acceleration is constant, zero, positive, negative, or changing ?

  5. V t chart v v 0

  6. V t graph v v v v v v v v v Could you draw:

  7. measuring acceleration

  8. measuring acceleration How many measure points we need to find: velocity, acceleration

  9. S t measuring velocity (t2, s2) (t1, s1) 2 measuring points V = displacement / time = (s2-s1)/(t2-t1)

  10. S t measuring acceleration (t3, s3) (t2, s2) (t1, s1) at least 3 measuring points a = change in velocity / time = (v2-v1)/(t2-t1) v1 = (s2-s1)/(t2-t1) v2 = (s3-s2)/(t3-t2)

  11. measurements using light gates t4 t1 t2 t3 l1 l2 4 measure points: t1, t2, t3, t4

  12. light gate t4 t1 t2 t3 l1 l2 average speed at t1 is u average speed at t3 is v

  13. light gate t4 t1 t2 t3 l1 l2 u = l1/(t2-t1) v = l2/(t4-t3) a = (v-u)/(t3-t1)

  14. measuring using ticker-timer start slow fast from slow to fast

  15. measuring using ticker-timer start fast slow cut each section

  16. measuring using ticker-timer fast slow place them side by side draw a line from slow to fast find slope of a line slope is acceleration start

  17. equations of motions

  18. introduction should you run or stop at yellow light?

  19. 5 variables s = displacement a = acceleration u = initial velocity v = final velocity t = time taken

  20. equations of motions

  21. how to use equations of motions • find what we know number for variables u, a, t, v, s • find what we want to know • which variable? • find the right equations of motions • substitude and calculate

  22. problem • A street is 10 m wide. Yellow light last for about 5 s. You know your top speed is 6m/s. You stand at one end of the street when traffic light turn yellow. Should you run or stop?

  23. problem • A street is 10 m wide. Yellow light last for about 5 s. You stand at one end of the street when traffic light turn yellow. How much you need to accelerate to cross? • a = ? • s = 10m • t = 5s • u = 0 • v - don't care

  24. problem • A street is 10 m wide. Yellow light last for about 5 s. You stand at one end of the street when traffic light turn yellow. How much you need to accelerate to cross? • a = ? • s = 10m • t = 5s • u = 0 • v - don't care • use equation

  25. problem a = ?, s = 10m t = 5s, u = 0 v - don't care 10 = a*25/2 a = 2m/s^2 As long as you can accelerate at 2m/s^2 you could cross the street.

  26. problem • a train accelerates steadily from 4.0m/s to 20m/s in 100s. • a. calculate the acceleration of the train. • b. from its initail and final velocitites, calculate the average velocity of the train.

  27. problem • a train accelerates steadily from 4.0m/s to 20m/s in 100s. • a. calculate the acceleration of the train.

  28. problem • a train accelerates steadily from 4.0m/s to 20m/s in 100s. • a. calculate the acceleration of the train. • given: u = 4.0, v = 4.0, t = 100, • ask: a = ? • use equation: v=u+at • rearrange equation

  29. problem • a train accelerates steadily from 4.0m/s to 20m/s in 100s. • b. from its initail and final velocitites, calculate the average velocity of the train. • use equation: v average = (v-u)/2

  30. problem • a train accelerates steadily from 4.0m/s to 20m/s in 100s. • c. calculate the distance travelled by the train in this time of 100s.

  31. problem • a train accelerates steadily from 4.0m/s to 20m/s in 100s. • c. calculate the distance travelled by the train in this time of 100s. • know: u = 4.0, v = 4.0, t = 100, • want: s = ? • use answer for part a • use equation: s = ut +at^2/2

More Related