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: Projectile Motion / Kinematics Lab (Only 2 Variables Given)

  1. Feb 13, 2012 #1
    1. The problem statement, all variables and given/known data
    So, our lab entails the students launching a projectile at a certain angle into a cup at a certain distance away. The launcher is 37 cm off of the ground and the cup is 7cm of the ground, so the Dy = 37-7 = 30cm. We will be given the angle in class and will be asked to position the cup at a certain distance. Lets say for example it is 35 degrees.

    How could we solve for Dx with only two variables.
    Any thoughts?


    2. Relevant equations
    tanθ = Vy/Vx

    3. The attempt at a solution
    I was thinking of using Vx = Vy/tanθ and then possibly substituting something in for Vy from another kinematic equation but that would require time and we are only given measuring tape, no timer.
  2. jcsd
  3. Feb 14, 2012 #2
    Hint: we are only given measuring tape.

    Welcome to PF!
  4. Feb 14, 2012 #3


    User Avatar
    Staff Emeritus
    Science Advisor
    Homework Helper

    Without knowing the initial speed of the projectile, this problem cannot be solved.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook