1 / 13

Motion Notes

Motion Notes. Overview. Mechanics – 2 parts. Kinematics Characteristics of motion Dynamics Causes of motion. Kinematics. Imagine a three legged stool and each leg is a fundamental parameter of motion: Position (distance/location) Time Speed. Kinematics – Position.

kiral
Download Presentation

Motion Notes

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. Motion Notes Overview

  2. Mechanics – 2 parts • Kinematics • Characteristics of motion • Dynamics • Causes of motion

  3. Kinematics • Imagine a three legged stool and each leg is a fundamental parameter of motion: • Position (distance/location) • Time • Speed

  4. Kinematics – Position • Position (linear measure) • Where an object is located at specific point in time • Units of meters • Can be described in terms of: • Distance (scalar) • measure from one position to another • Displacement (vector) • measure from one position to another in a direction • distance from the start point to the finish point in a straight line, in a certain direction Stop here

  5. Kinematics - Speed • Definition • Rate of change of position • Average Speed (scalar) = distance traveled time taken to travel the distance • Velocity (vector) = displacement time taken • When traveling in a straight line, speed and velocity have the same magnitude. • vav = d/t • Units: meters/second (m/s) • Distance is to speed (both scalar quantities) as displacement is to velocity (both vector quantities).

  6. Example – speed • Usain “Lightning” Bolt won the World Track & Field 100m sprint in 9.58 seconds. What was his average speed in m/s? • Solve: avg speed = distance/time • Speed (v) = 100/9.58 = 10.438 m/s

  7. Example - segments • A traveler uses a cab to travel east for 1000 m @ 25 m/s then north for 1700 m @ 10 m/s. How long is the trip? • Solution: break the trip into segments and use d = v*t or t = d/v to find the segment times – then add. • Seg 1: t = 1000/25 = 40 seconds • Seg 2: t = 1700/10 = 170 seconds • Total time = 40 + 170 = 210 seconds.Stop

  8. http://www.physicsclassroom.com/Class/1DKin/U1L1c.cfm see teachers tab

  9. Kinematics - Acceleration • How do you pass a car on I-81? • Definition • Rate of change of velocity • a = v/t, or • a = (vf – v0)/t, where • vf = final (ending) velocity • v0 = initial (starting) velocity • t = time taken for the velocity to change • units: meters/sec/sec, or meters/sec2 (m/s2) • VECTOR! • Average speed (alternative formula) • Vav = (v0 + vf)/2

  10. Example - acceleration • A funny car accelerates from zero to 300 mph (135 m/s) in 5 seconds. What is its acceleration? • Solve: acceleration = (vf– vo)/t • a = (135 - 0)/5 • a = 27 m/s/s • a = 27 m/s2 • g-forces?STOP

  11. Kinematics – Graphs (Distance vs Time) • slope = velocity or speed of the object • Steep (left) slope = higher speed • Zero slope (flat line) = object stationary • Slope can be + or – indicating motion direction

  12. Kinematics – Graphs (Velocity vs time) • slope is acceleration • Steep (left) slope = higheraccel’n • Zero slope (flat line) = zero accel’n or the object is moving at constant speed • Slope can be + or – indicating speed direction STOP

  13. Practice - Handouts • H/O Interpretation of Motion Graphs • D-T & V-T • H/O d-t & v-t graph worksheet • D-T & V-T • H/O Position Time • D-T & V-T

More Related