Retro Bob said:OK, all you amateur physicists:
If a 155 pound mass (me) is traveling at 10 mph (on bike) and I
strike an object dead on with my shoulder (roughly 2 sq inches) -
what the load presented by my shoulder to the object.A rough calculation of 150lbs concentrated into 2 sq inches tells
me that the static load would be 75 lbs/inch... but obviously
the 10 mph would be the key here... and I forgot more physics than
I ever really understood.
As others said, no way to figure out how much pressure on your
shoulder. We can estimate a couple of things though, just for fun.
If you weigh 70kg (155lbs) and you hit a wall while traveling at 4.5
m/s (10mph) and you come to a complete stop then we know you
experienced an impulse of 315 kg*m/s, which is just your change in
momentum, and has units of force * time. So, if we know how long it
took you to come to a stop we can estimate the average force. Say it
took 1/10 second to stop, then the average force would be (315
kg*m/s)/(1/10 s) = 3150 kg*m/s^2 = 3150N = 708 lbs force. If you
stopped in 1/100 of a second it would be 7000 lbs force. The folks
who study this sort of thing like to look at how many g's your body
experiences. If you stop in 1/10th of a second that is only 4.5 g's,
not a problem. stopping in 1/100th of a second is 450, which will
break things. I think in the scenario you describe you would be look
at a number somewhere between those above.