I was in a crosswalk, struck by a truck weighing 3,400 lbs. (traveling at about 8 K/hr) - what was the force per square inch exerted on me?
I do not know. Was this question in your text? It depends how squishy you are.F = m a = rate of change of momentum = m *(change in speed/time to change speed)
But time to change speed from zero to speed of the truck depends on howmuch the truck compresses you on contact. If you do not compress then you change speed instantly and the force is infinite. Of course you also did not give the area of your body exposed to the force so we can not get pressure anyway. Did you make this question up yourself?