Impulsive force physics free#

The SI unit of impulse is the newton second (N⋅s), and the dimensionally equivalent unit of momentum is the kilogram meter per second (kg⋅m/s). Impulse applied to an object produces an equivalent vector change in its linear momentum, also in the resultant direction. Since force is a vector quantity, impulse is also a vector quantity. If you land in the water, you'll drown before anyone can get to you anyway, so better to hit the land and have a chance of being rescued and taken to hospital.In classical mechanics, impulse (symbolized by J or Imp) is the integral of a force, F, over the time interval, t, for which it acts. If by amazining chance you surive the fall, you are going to be very badly injured, stunned, possibly unconscious and in shock whether you hit land or water. There are some articles online about cliff jumpers and how much water they require which might help you.īut I suspect the reason for aiming for land isn't to do with physics. For a tall tree, that could be more than the time it takes to slow down in water.

The force you experience (which is what you are interested in) is inversely proportional to the distance over which you decellerate from whatever your fall speed is to zero. But the video does say to aim for swamp, snow or trees, so that is going to narrow the difference, and I can imagine a landing in a tree might break your fall better than water.

Impulsive force physics free#

(If you still have any doubts, feel free to ask!)īare land is always going to hit you harder than water if you've ever jumped into a swimming pool that was shallower than you thought it was, you'll know what I mean. Remember all this the next time you're falling out of a plane and your parachute fails. For example, if you (for some reason) decide to land on concrete, it would equal the same amount of devastation as water. Any practically-incompressible liquid/solid would act the same. Even though that may be the case for smaller heights, for larger heights, falling on water basically means death because of the reasons stated above. One general misconception (which you too have fallen for) is that 'land is harder than water'. That means if you impact with water from such a large height, instead of giving way, it just halts your descent instantly, resulting in a very large impact force. Water, on the other hand, is infamous for being incompressible. Land consists of trees, snow, stacks of hay et cetera, and all these things would be your best bet to land on if you're falling from such a great height, precisely because of the reason stated above - they slow your descent down bit-by-bit. The fallacy in your comparison between 'land' and 'water' is that land is not a homogenous material.

But if the momentum is reduced gradually by slowing down your descent bit-by-bit, the time period would be longer and consequently the impact force would be smaller, and that's exactly what makes some things better to fall on. In other words, if your momentum is reduced from a very high number (something you'd expect if you're falling from a plane) to zero INSTANTANEOUSLY, the impact force would be extremely large. Force can also be written as the 'rate of change of momentum', which means force is inversely proportional to the time period it is applied for. The reason why some things are better to fall on than others is because of how fast the momentum is reduced.