Successfully reported this slideshow.
We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. You can change your ad preferences anytime.

Chapter 8


Published on

Published in: Business, Technology
  • Be the first to comment

  • Be the first to like this

Chapter 8

  1. 1. Relative Velocity <ul><li>Do objects always go where you think that they will? </li></ul>
  2. 2. Relative Velocity <ul><li>When we consider velocity, it is a vector. So has both magnitude and direction. </li></ul><ul><li>When 2 things are moving with a velocity they may affect one or both of the objects </li></ul><ul><li>On lined paper, draw the velocity vector for a plane moving South at 300m/s </li></ul>
  3. 3. Compass Headings
  4. 4. Flying South <ul><li>300m/s </li></ul>But alas, there is a westerly wind of 20m/s. What effect will it have on your journey? 20m/s
  5. 5. Flying South <ul><li>300m/s </li></ul>There will be a RESULTANT VELOCITY due to the 2 vectors Calculate its magnitude and heading 20m/s
  6. 6. Flying South <ul><li>300m/s </li></ul>Resultant = 301m/s Angle = Tan  = 20/300  = 3.81 degrees 20m/s  301m/s
  7. 7. Flying in a pre-determined direction <ul><li>What if you want to fly South but the wind is the same, 20m/s from the West? </li></ul><ul><li>Which way should you head? </li></ul>Required Direction (resultant) Wind 20m/s
  8. 8. Vector Addition <ul><li>Sin  = </li></ul><ul><li>V air / V plane </li></ul><ul><li>= 20 /300 </li></ul><ul><li> = 3.82 </li></ul><ul><li>Resultant v = √300 2 – 20 2 </li></ul><ul><li>= 299m/s </li></ul>Velocity of plane is 300m/s at 183.2 heading Wind 20m/s 299 m/s resultant Velocity
  9. 9. Rules of Vector Addition <ul><li>Vectors are drawn with a magnitude and direction – usually as headings for velocity. E.g. North </li></ul><ul><li>Additional vectors are added to the end of the first and drawn in the same direction if they are going in the same direction (relative to the first) </li></ul><ul><li>Additional vectors are subtracted from the end of the first and drawn in the opposite direction if they are going in the opposite direction (relative to the first) </li></ul><ul><li>Other vectors that are not parallel can be put end to end to work out either resultant or required velocities </li></ul>