Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Free fall and impact force calculation

  1. Oct 8, 2010 #1
    first of all I have a case that is screwed in another case ,I like to know a basic way to calculate the impact force in the screws ,the are 16 screws, I try using the basic impact force formula and the conservation of energy in the free fall,but Im having problems since I dont have the D wich apparently its the distance after the impact.The weigh of the box is 27 lbs and its throwed from 5 ft.
  2. jcsd
  3. Oct 8, 2010 #2


    User Avatar
    Science Advisor

    It's impossible to know what the impact force is going to be without knowing some properties of the falling object and the surface they are hitting.

    The force will depend on the amount of time the impact takes. With softer surface, impact will take longer, and forces will be lower.
  4. Oct 11, 2010 #3
    thnax,can i incorporate that information to the formula,I mean if I findt hat kind of info
  5. Oct 12, 2010 #4
    Impact force

    I have a 27 pound box attached to a another box by 16 screws in 4 brackets one for every corner,I like to compare the effect of the impact if I put 16 screws or if I put 24(like the number of holes in the bracket).It would be dropped from 5 ft to a concrete slab,the material of the outside box its a TSC composite material.So I think what I need its the impact force that will received the box and that will tranfer to the screws,after that I can divided by the section area of the screws and compare that to the shear modulus,but Im not sure.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook