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: Help with vectors!

  1. Jan 26, 2010 #1
    A web page designer creates an animation in which a dot on a computer screen has a position of r= [3.5 cm + (2.8 cm/s2)t2]i + (5.4 cm/s)t.j

    (a) Find the magnitude and direction of the dot's average velocity between t = 0 and t = 2.2 s
  2. jcsd
  3. Jan 26, 2010 #2
    the operations/operands being multiplied to i and j are just scalars (regular numbers), you can just plug in the values of t and use the distance/time formula. Then the direction of the final vector may be determined by an angle off the horizon. If you have your vector coming from the origin (0,0), you will know the length of your sides, then you can just take arctan( ratio of sides ). For magnitude, use pygthoras' theorem for the x side and the y side you can imagine from your x and y components
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook