Return to Video

10x-11 Dead Reckoning

  • 0:00 - 0:03
    In Unit 5 we briefly mentioned dead reckoning.
  • 0:03 - 0:07
    Dead reckoning is the method that mariners used to use to estimate their position at sea.
  • 0:07 - 0:11
    They did this by keeping a log book of the direction they were heading,
  • 0:11 - 0:16
    they speed they were moving at, and the duration that they moved at that speed and direction.
  • 0:16 - 0:21
    In one particular journey where a ship wants to get from start to finish
  • 0:21 - 0:27
    the ship starts out by going east at a speed of 12 k/h for 2.5 hours.
  • 0:27 - 0:31
    The ship then heads south at 20 m/h for 1 hour,
  • 0:31 - 0:38
    east at 15 m/h for 3 hours and then finally northeast at 8 k/h for 1 hour.
  • 0:38 - 0:44
    My question is what's the straight-line distance between start and finish.
  • 0:44 - 0:50
    By straight-line distance, I mean this distance from start to finish.
  • 0:50 - 0:55
    Not the total distance the ship traveled, because the ship took a slightly inefficient route.
  • 0:55 - 0:58
    Now, this is a sort of tricky problem, but as long as you keep track of your trignometry
  • 0:58 - 1:02
    and geometry, and you will have to make some right triangles,
  • 1:02 -
    you'll be able to get this one right. Enter your answer here in kilometers.
Tytuł:
10x-11 Dead Reckoning
Video Language:
English
Team:
Udacity
Projekt:
PH100 - Intro to Physics
Duration:
01:06
Amara Bot added a translation

English subtitles

Revisions