1. Not finding help here? Sign up for a free 30min 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!

The Blasted Elevator Questions; General Physics- Please help!

  1. Sep 30, 2006 #1
    hey everyone,
    sheesh, our professor has us do our homework online, and I SWEAR my answer is right, but apparently it isnt. Here is the question:

    You leave the doctors office after your annual checkup and recall that you weighed 684N. You then step onto an elevator with a scale. Find the magnitude of the elevator's acceleration if the scale reads 724N.

    How do i solve this problem?
    Thanks.
     
  2. jcsd
  3. Sep 30, 2006 #2
    Essentially, what I did was divide her weight in the drs office by 9.8, then I entered that mass into newtons 2nd law equation. I divided 724 by mass--- Doesn't that give me the acceleration?
     
  4. Sep 30, 2006 #3
    You're supposed to show your work when asking questions. We're not doing your hw for you.

    However, find the mass, m = 684/9.81 = 69.7 kg. Find the difference between your weight at rest and your weight on the accelerating elevator. 724-684 = 40 N. Now, find the acceleration. a = 40/69.7 = 0.574 m/s^2.
     
    Last edited: Sep 30, 2006
  5. Sep 30, 2006 #4
    The net force is not 724N. 724N is the sum of the normal force exerted by the elevator and your weight.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?



Similar Discussions: The Blasted Elevator Questions; General Physics- Please help!
Loading...