1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Relative Velocity of a plane

  1. Jun 7, 2008 #1
    a,The Speed Of an aircraft in still air is 300 km/h.
    In a wind of speed 140 km/h, blowing from a bearing of 230, the aircraft flies due east. Find
    i, the course set by the pilot
    ii, the time taken for the aircraft to travel 100 km.

    b,To a cyclist traveling due east at 18 km/h the wind appears to be blowing at 12 km/h from a bearing of 150. Find the true wind-speed and the direction from which the wind is blowing.
  2. jcsd
  3. Jun 7, 2008 #2


    User Avatar
    Science Advisor
    Homework Helper

    Where's your attempt at a solution?
  4. Jun 7, 2008 #3
    how to draw a vector diagram ?? of the above problem?? I only have problem in that...
  5. Jun 7, 2008 #4
    its all simple trigonometry .... after that... i need to know what will be the direction of Aircraft in still air? what does that mean? what will be the direction of of wind... how will we create a vector diagram...of it?
  6. Jun 7, 2008 #5
    You should be able to draw 3 vectors, where one of them is the final speed and direction of the moving object(which you can find by vector addition).
  7. Jun 8, 2008 #6


    User Avatar
    Science Advisor
    Homework Helper

    Hi Zoheb! :smile:

    Give them letters!

    Call the plane P, the air A, and the ground G.

    Then P - A = 300, and A - G = 140 @ 230º.

    And you know that P - G is 90º.

    Draw a triangle with an arrow on each side, so that the arrow along P - A goes the same way as the arrow along A - G (in other words, it doesn't meet it head-on).

    Does that make sense? :smile:
    Not relevant … in still air, it would go at 300 in any direction … they're simply telling you how powerful the aircraft is.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook