Initial Velocity Question

  1. Ok So if I were to launch a waterballoon with a waterballoon launcher VERTICALLY , how could I find out the Initial Velocity With OUT a stop watch? My other supplies include a meter stick
     
  2. jcsd
  3. Are you familiar with conservation of energy?
     
  4. This is for a lab at school and you get Extra Credit if you can figure out the first part without a stop watch. Would i have to weigh it? And sorry, im not familiar with conservation of energy
     
  5. Ok, are you familiar with the equations of motion?
     
  6. I am familiar with the equations for angles ( sin, cos), displacement in X,Y , etc,, for constant/non constant velocities and Trajectories
     
  7. Look through them and try to find one that involves the parameters you think are going to be important and post it.
     
  8. This isnt really a homework question but w/e

    Thanks again
     
  9. Well if I am shooting an object vertically then Displacment X will be 0m, and
    Vy = Vo * sin(90) because the degrees will be 90
    VFy = 0 m/s

    Thats about all the variables i know atm

    Im unsure of which equation to use
     
    Last edited: Nov 4, 2006
  10. Well, dont solve any equations yet, just look for some that might be useful, and well work from there.
     
  11. Would this work
    VFy^2 = VOy^2 + 2a*Displacment Y
     
  12. Aha, you are on to something. Keep going.
     
  13. Displacment Y = {(Vo^2+sin(2*angle)} / g

    Only other one i know that doesnt involve time
     
    Last edited: Nov 4, 2006
  14. where did this come from? You were on the right track before. Maybe you should take a closer look at your first equation.
     
  15. its equation for X or Y displacment
    I am looking for Initial Velocity (Vo) and those two are the only ones that do not include time because i wont have a stop watch when doing this experiment
     
  16. Yes, look at your first equation, and you tell me what each of those terms mean.
     
  17. VFy^2 = VOy^2 + 2a*Displacment Y
    I am looking for Initial Velocity and not just VOy
    Final Velocity of Y = is 0 m/s in this case
    VOy^2 = is unknown
    a = 9.81m/s^2 in this case
    Displacment Y = is also unknown
     
  18. Ok, we need to get this terminology straight.

    [tex]V_{fy}[/tex] means the final velocity in the y direction.

    [tex] V_{oy} [/tex] means the initial velocity in the y direction.

    Does this help at all?

    Yes, that's correct. Now when does this occur?
     
  19. VFy That occurs when the object stops right before it comes back down
    I Know what the terminology means,
     
  20. How would a ruler be useful given this information? What is the value of Vfy?
     
  21. Thats the thing, I have almost no idea
     
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