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: Another Uncertainty with Equations question

  1. Jan 15, 2012 #1
    1. The problem statement, all variables and given/known data

    A useful kinematic equation is

    (vf)^2 = (vi)^2 + 2ad

    You drop a ball (with zero initial velocity) from the top of a building to measure the acceleration due to gravity. If you measure the final velocity to be vf ± ∆vf, and the height of the building to be d ± ∆d, what is the relative uncertainty in your determination of the acceleration?

    2. Relevant equations

    Uncertainties equations, propagation of error.

    3. The attempt at a solution

    This time I'm really not sure. Should I first rearrange the equation to solve for acceleration, and then do my propagation of error? Or do I take it as it is right now?
     
  2. jcsd
  3. Jan 15, 2012 #2
    yes I think you should solve for acceleration, and you just drop vi because its zero and the uncertainty in that is negligible.
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook