why do we get hurt more when we fall on a cemented floor than when we fall on sand. i want a physics answer.?

Question

Hey! i want a real physics answer .I'm a high school student in standard 11

Answer 1

Because the more time it takes for an impact to finish once it impacts, the lesser the push back will be.

Since cement is much harder than sand, it doesn't "move" as much when you hit it. With the sand not pushing back on you as hard, it makes the impact take longer. It's like stopping a car in 3 seconds, instead of 1/2 a second. Much less rough :)

Answer 2

When we fall we are literally a moving body. In motion we have momentum known as kinetic energy. If we are stopped abruptly by hitting something solid the kinetic energy has no further it can go in the same direction so it is bounced back from the concrete back to our softer and more absorbent (of shock) body.

If we fall on sand some of the kinetic energy is absorbed by action of the the sand slowing us before we stop. Some is dissipated in the relatively soft sand and a little is bounced back into our body.

Sand also moulds itself to the body falling into it so that the shock is transferred over a bigger surface area but in cement the first points of contact take the bulk of the energy concentrating the pain at those points.

Answer 3

it is due to ..impusle is force *time taken.........let the time taken to fall on a cemented floor be 't' sec ...when u now fall on a sand it acts lke a cution and the time of contact is more ...so it is basically 't +t1' so even tough the force is the same the impact is
differnent ...it can also explain the fact that when u catch a ball u move ur hands in the direction of the ball...increasing the time of contact....if u catch it rigidly then it hurts our hand.....

Answer 4

floors are rigid & thus when we fall acc. to newtons third law the applies the same amount of force on us with which we were falling on it (ur weight)
but sand is not rgid on impact it changes its shape and this absorbs a large amount of ur falling force & only a small fraction of this force applied on u
so u dont get hurt too badly

Answer 5

The fall decreases abruptly because concrete is hard and your velocity stops fast, like hitting a wall. While, the sand absorbs your falling energy spreading it out over time.

Answer 6

It is due to change in momentum(p) in lesser time.
change in p = MxVf -MxVi
this change is called impulse and = to Fxt i.e
Fxt = MxVf -MxVi
suppose you've jumped from roof.your Vi=0 and Vf=a(let) and your mass is constt.so chang in p is constt. whether you fall on sand or cement.
but looking on other side of eq. Fxt must be constt. here t is time of change of p. on sand your time is greater as it'll deaccelerate you first then stop slowly(imagine situation uptill here) your tie is greater so force is lesser as Fxt=constt.
on falling on cement change in p will take place in no time so F is greater.
thats why keeper of foot ball or cricket move his hands just after recieving ball so that he can stop ball in greater time and effected by lesser force.

Answer 7

Basically when the sand deforms it absorbs some of the energy which leaves less energy for your butt to absorb...Think about the way they build cars these days with the front crumble zone.