2
$\begingroup$

My lack of physics knowledge is preventing me from solving an everyday life problem. Please bear with me!

Say I have a second-floor apartment and I want to do deadlifts. I am afraid of the floor collapsing into the apartment below mine if I accidentally drop a heavy barbell from some height.

I was thinking about using a thick rubber mat to mitigate the issue. I believe a rubber mat would at least reduce the sound of the barbell hitting the floor, but I am not sure whether a rubber mat would actually reduce the impact to the building structure.

Can someone explain the physics to me? If possible, please provide some math to help establish the relationship between the thickness of the rubber mat and the reduction of force on the floor, if any.

$\endgroup$
4
  • $\begingroup$ You need to read the article you linked. You're misunderstanding what the issue is. The cause is not due to you dropping a barbell. $\endgroup$
    – Nelson
    Commented May 23 at 2:16
  • $\begingroup$ Can you elaborate? I see two issues discussed in the article: the weight at rest and dropping a barbell. I’m asking about the second issue: “If you’re dropping the barbell at all, the shock load goes way beyond its total weight, and you could run into trouble.” $\endgroup$
    – fumoboy007
    Commented May 23 at 2:52
  • $\begingroup$ The quote then goes on to say "We’ll get into that below." Did you read that? The whole article literally covers how to setup your gym. $\endgroup$
    – Nelson
    Commented May 23 at 4:12
  • $\begingroup$ @Nelson Your comments feel a little hostile. Yes, I read the article. As noted in the last paragraph of my question, I am not looking for a how-to on setting up my gym; I am asking specifically about the physics of a rubber mat. If you have something to contribute, then feel free to post an answer. $\endgroup$
    – fumoboy007
    Commented May 23 at 5:49

1 Answer 1

3
$\begingroup$

If dropped, the falling barbell will carry a considerable amount of kinetic energy when it hits the floor. Preventing damage to the floor involves managing that impact energy. Here is how to do it:

A thin rubber mat has little energy-absorbing capacity compared to, for instance, a 1" thick sheet of rigid foam insulation (available at hardware stores). And if we place a sheet of 1/4" plywood on top of the rigid foam, it will spread out the impact over a large area of the foam- which will then absorb the impact energy as it crushes down under the plywood.

Then if we put a sheet of rubber floor mat material on top of the plywood, the dropped barbells will not go BANG! when they strike the plywood.

In summary: soften the blow to minimize noise, spread the impact over a large area, and absorb the energy through crushing.

$\endgroup$
1
  • $\begingroup$ Thanks for your answer! I am interested in the physics of “absorbing the impact energy”. Can you elaborate on that? For example, here is what ChatGPT has to say about it: chatgpt.com/share/3283d1cb-6756-4689-b01e-3507c3a59160. (I don’t want to just trust ChatGPT though.) $\endgroup$
    – fumoboy007
    Commented May 23 at 5:45

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.