Free fall and impact force calculation

AI Thread Summary
Calculating the impact force on screws requires understanding the properties of both the falling object and the surface it impacts. The impact force depends on the duration of the impact; softer surfaces result in longer impact times and lower forces. The weight of the box is 27 lbs, and it is dropped from a height of 5 ft onto a concrete slab. The discussion also explores the difference in impact effects between using 16 screws versus 24 screws in securing the boxes. Ultimately, to accurately determine the impact force on the screws, one must consider the material properties and the area of the screws in relation to the shear modulus.
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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 I am having problems since I don't have the D which apparently its the distance after the impact.The weigh of the box is 27 lbs and its throwed from 5 ft.
 
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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.
 
thnax,can i incorporate that information to the formula,I mean if I findt hat kind of info
 
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 I am not sure.
 
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