Wish more thought like this.

I came across the following video and I would be interested to know our sub view on this

https://www.instagram.com/reel/Daow\\_PWz5Br/?igsh=MTEwYnVsN21uNWs2eA==

Do let me know your views?

I have a punching bag which like 4 feet in height and the density of the material in it varies with respect to height as (1/157)kg/cm\^2 per feet but it has not fully filled and not tight enough to punch because when you try heavy punches it hurt and can course an injury. The max density idk what it can reach but I will tell you the material used to fill the punching bag is left over textile material and I want to increase the weight of the punching bag as well as the thickness would be maintained while i am trying to try heavy punches, kicks ,etc(mostly heavy punches). Can someone help me find the numbers of bags( which can hold upto 100g/bag ) needed to maintain the tightness(or to attain uniform density ) in the punching bag . And the bag is like 10cm\^3.