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: Find Initial Velocity (With Wind Factored In)

  1. Feb 16, 2010 #1
    [Please Help!!!] Find Initial Velocity (With Wind Factored In)

    1. The problem statement, all variables and given/known data

    2. Relevant equations

    3. The attempt at a solution
    I can't do it =\.

    Q: What equation would I use to find initial velocity? Given: Wind Speed, Wind Angle, Coordinates of Origin, Coordinates of End Point, (Distance), Projectile Mass, Theta (Angle to Use)

    Here's my repost from a previous topic:

    Hey Physics Forums. This is my first post here, and I'm just wondering about how to find what the initial velocity SHOULD be based on all the other information that I provide (it's for a program application I coded).

    Anyways, I have this right now (which is for no wind/0 wind):

    I am just wondering how I would go about factoring in the "wind" and wind's angle.

    Wind Angles:

    ^ 90
    < 180 > 0
    \/ 270

    As you can see, the wind angle starts at East 0 and increases counter-clockwise.

    Anyways, here's the formula:

    Velocity = Sqrt((Mass * (DifferenceInX^ 2)) / (2 * (DifferenceInX) * Sin(Theta* PI / 180) * Cos(Thtea * PI / 180) - (2 * (DifferenceInY)) * ((Cos(Theta* PI / 180) ^ 2))))

    Where Theta is the angle of the shot; Difference in X is the difference in coordinates X of the starting position and where you want the shot to end; and DifferenceInY is the difference in coordinates Y of the starting and ending position.

    Please help me out! Thanks.

    I don't take a Physics course yet, I'm enrolled in Algebra 2 at the moment, but am heavily interested in the Physics course of study, so please do help me out!

    I need an equation, like the one above, that will work in my computer program.
    Last edited: Feb 16, 2010
  2. jcsd
  3. Feb 16, 2010 #2
    Also, the velocity remains constant; it doesn't change...
  4. Feb 16, 2010 #3
    I don't know why my question hasn't been answered as of yet! This isn't homework, this is off-to-the-side-what-I-do work.

    I have no idea how to begin to make this all work. I've been looking for an answer for over 5 months!!!
  5. Feb 16, 2010 #4
    I'll include a picture with equations for finding initial velocity in zero wind.

    Attached Files:

  6. Feb 16, 2010 #5
    The final line is the line to find initial velocity in 0 wind.

    Velocity = Sqrt((Mass * (DifferenceInX^ 2)) / (2 * (DifferenceInX) * Sin(Theta* PI / 180) * Cos(Thtea * PI / 180) - (2 * (DifferenceInY)) * ((Cos(Theta* PI / 180) ^ 2))))
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook