1 / 20

Understanding Motion: Speed, Velocity, Acceleration, and Newton's First Law

This resource covers essential concepts of motion, including speed, velocity, and acceleration, along with Newton's First Law of Motion. It explains that an object at rest stays at rest, and an object in motion continues at constant velocity unless acted upon by a net force. Topics such as reference points in measuring motion, the distinctions between instantaneous and average speed, and positive and negative acceleration are explored. Engage with practical problems and calculations like determining speeds and acceleration in various scenarios to reinforce learning.

gusty
Télécharger la présentation

Understanding Motion: Speed, Velocity, Acceleration, and Newton's First Law

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. Ch. 3 & 4Motion & Forces II. Describing Motion Motion Speed & Velocity Acceleration

  2. Newton’s First Law • Newton’s First Law of Motion • An object at rest will remain at rest and an object in motion will continue moving at a constant velocity unless acted upon by a net force. motion constant velocity net force

  3. A. Motion • Problem: • Is your desk moving? • We need a reference point... • nonmoving point from which motion is measured

  4. Reference point Motion A. Motion • Motion • Change in position in relation to a reference point.

  5. A. Motion Problem: • You are a passenger in a car stopped at a stop sign. Out of the corner of your eye, you notice a tree on the side of the road begin to move forward. • You have mistakenly set yourself as the reference point.

  6. d v t B. Speed & Velocity • Speed • rate of motion • distance traveled per unit time

  7. B. Speed & Velocity • Instantaneous Speed • speed at a given instant • Average Speed

  8. B. Speed & Velocity • Problem: • A storm is 10 km away and is moving at a speed of 60 km/h. Should you be worried? • It depends on the storm’s direction!

  9. B. Speed & Velocity • Velocity • speed in a given direction • can change even when the speed is constant!

  10. vf - vi t a C. Acceleration • Acceleration • the rate of change of velocity • change in speed or direction a: acceleration vf: final velocity vi: initial velocity t: time

  11. C. Acceleration • Positive acceleration • “speeding up” • Negative acceleration • “slowing down”

  12. d t v D. Calculations • Your neighbor skates at a speed of 4 m/s. You can skate 100 m in 20 s. Who skates faster? GIVEN: d = 100 m t = 20 s v = ? WORK: v = d ÷ t v = (100 m) ÷ (20 s) v = 5 m/s You skate faster!

  13. vf - vi t a D. Calculations • A roller coaster starts down a hill at 10 m/s. Three seconds later, its speed is 32 m/s. What is the roller coaster’s acceleration? GIVEN: vi = 10 m/s t = 3 s vf = 32 m/s a = ? WORK: a = (vf- vi) ÷ t a = (32m/s - 10m/s) ÷ (3s) a = 22 m/s ÷ 3 s a= 7.3 m/s2

  14. d t v D. Calculations • Sound travels 330 m/s. If a lightning bolt strikes the ground 1 km away from you, how long will it take for you to hear it? GIVEN: v = 330 m/s d = 1km = 1000m t = ? WORK: t = d ÷ v t = (1000 m) ÷ (330 m/s) t = 3.03 s

  15. vf - vi t a D. Calculations • How long will it take a car traveling 30 m/s to come to a stop if its acceleration is -3 m/s2? GIVEN: t = ? vi = 30 m/s vf = 0 m/s a = -3 m/s2 WORK: t = (vf- vi) ÷ a t = (0m/s-30m/s)÷(-3m/s2) t = -30 m/s ÷ -3m/s2 t = 10 s

  16. Distance-Time Graph A B E. Graphing Motion • slope = • steeper slope = • straight line = • flat line = speed faster speed constant speed no motion

  17. Distance-Time Graph A B E. Graphing Motion • Who started out faster? • A (steeper slope) • Who had a constant speed? • A • Describe B from 10-20 min. • B stopped moving • Find their average speeds. • A = (2400m) ÷ (30min) A = 80 m/min • B = (1200m) ÷ (30min) B = 40 m/min

  18. Distance-Time Graph E. Graphing Motion • Acceleration is indicated by a curve on a Distance-Time graph. • Changing slope = changing velocity

  19. Speed-Time Graph E. Graphing Motion • slope = • straight line = • flat line = acceleration • +ve = speeds up • -ve = slows down constant accel. no accel. (constant velocity)

  20. Speed-Time Graph E. Graphing Motion Specify the time period when the object was... • slowing down • 5 to 10 seconds • speeding up • 0 to 3 seconds • moving at a constant speed • 3 to 5 seconds • not moving • 0 & 10 seconds

More Related