20,000-lb. Bus vs. 165-lb. Pedestrian -- Analogy Needed
20,000-lb. Bus vs. 165-lb. Pedestrian -- Analogy Needed
(OP)
Hi,
Here's a true scenario: A 50 year-old female of average height and weighing 160-lbs. steps off a curb and is hit square-on by a 20,000-lb. bus going a steady 10-mph. The bus impacts the woman at 10-mph, then stops. The woman is first knocked up into the windshield of the bus, then "bounces" off the windshield and lands in the street (an unknown distance from the front of the bus). She survives the accident, sustaining a fractured arm, rib and skull.
Here's my question: Can someone come up with a real-world, more human-sized physical analogy for this incident? In other words, in terms of impact force, can this pedestrian-vs-bus scenario be reasonably equated to, say, someone being hit by a football linebacker of X weight and running at X speed? If so, what would that weight be, and what would that speed be? Or perhaps there's a better, more illuminating physical analogy that someone could come up with. I realize the variables at play in the bus-vs-pedestrian situation are myriad, but I am just seeking a reasonable analogy.
My powers of forensic force analysis pretty much end at KE = 1/2 m v^2, so I'm looking for some help here.
Thanks in advance for any input.
Here's a true scenario: A 50 year-old female of average height and weighing 160-lbs. steps off a curb and is hit square-on by a 20,000-lb. bus going a steady 10-mph. The bus impacts the woman at 10-mph, then stops. The woman is first knocked up into the windshield of the bus, then "bounces" off the windshield and lands in the street (an unknown distance from the front of the bus). She survives the accident, sustaining a fractured arm, rib and skull.
Here's my question: Can someone come up with a real-world, more human-sized physical analogy for this incident? In other words, in terms of impact force, can this pedestrian-vs-bus scenario be reasonably equated to, say, someone being hit by a football linebacker of X weight and running at X speed? If so, what would that weight be, and what would that speed be? Or perhaps there's a better, more illuminating physical analogy that someone could come up with. I realize the variables at play in the bus-vs-pedestrian situation are myriad, but I am just seeking a reasonable analogy.
My powers of forensic force analysis pretty much end at KE = 1/2 m v^2, so I'm looking for some help here.
Thanks in advance for any input.





RE: 20,000-lb. Bus vs. 165-lb. Pedestrian -- Analogy Needed
There basically is no good analogy, since a linebacker is still made of flesh and bones, albeit padded, while a bus is made from hard materials throughout, e.g., metal or plastic. So, I guess about a 5:1 difference in effective force. Bear in mind that a normal linebacker only does about 20 mph.
TTFN
RE: 20,000-lb. Bus vs. 165-lb. Pedestrian -- Analogy Needed
RE: 20,000-lb. Bus vs. 165-lb. Pedestrian -- Analogy Needed
TTFN
RE: 20,000-lb. Bus vs. 165-lb. Pedestrian -- Analogy Needed
RE: 20,000-lb. Bus vs. 165-lb. Pedestrian -- Analogy Needed
RE: 20,000-lb. Bus vs. 165-lb. Pedestrian -- Analogy Needed
the speed is not really high, the impact is pretty much the same as a marathon runner could suffer if he hits a standing still bus, running at cruise speed.
one question. are you sure the woman bounced from the bus, or was it just that the bus was stoping after the impact?
RE: 20,000-lb. Bus vs. 165-lb. Pedestrian -- Analogy Needed