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View Full Version : How many pounds of force per square inch from a coyote delivering 300n of force?


TheAmateur
Jul 26, 2012, 04:47 AM
All right, so I've ran into coyotes a couple of times on vacation now. First time scared me a little, after that I researched them.

Based on average weight and top speed of a coyote, a pounce at me can deliver 300N(n?? ) of force.

With a surface area of, oh, I'd estimate around 26x12in. So 312in.^2, how many pounds per square inch would this pounce deliver?

I guess this is almost like I'm trying to figure out the "punch power" of a leaping coyote.

Acceleration (or a better term would probably be velocity): 40mph.
Mass: 40lbs.
Force: 300N (after all conversions were done with the help of an online calculator)

I am trying to explain to the others who were walking with me that night that there is no need to be scared of something that averages about 28lbs. and this would help my argument, lol.

*please ignore all facts not related to question, such as the very low number of coyote attacks on humans, etc. etc.*

ebaines
Jul 26, 2012, 05:02 AM
I'm not sure how you arrived at 300N, but be that as it may...

300N is equivalent to 67.4 pounds of force. Divide by the area of 312in^2 and you get about 0.21 pounds per square inch.

There are a couple of issues with this estimation technique. First the impact of a 40 pound object at 40 MPH is going to be many times greater than 67 pounds. Imagine a 40 pound weight falling on you from a height of 50 feet - that's what the impact would be like. I would estimate that deceleration of the coyote is about, oh, 5 g's. Hence the force is about 5 x 40 = 200 pounds.

The second issue is that the impact isn't spread over the surface area that you estimated, but rather would be concentrated. Hence the PSI in that area is much greater than your estimate.