Same location, look for the tall white tower with the vertical stripes and balconies, which is in the middle of the bottom photo. Top photo is slightly more zoomed out.
At the risk of feeding the troll, here is the math you are suggesting we do, which disproves all of your arguments. It pains me how confidently you speak of a topic you are clearly so uneducated about: your physics mentors should be disappointed in you.
Conservation of linear momentum:
m1v1i + m2v2i = m1v1f + m2v2f
Let the vehicle be m1 and the human m2. Let the human's initial velocity be zero. Let us further assume an inelastic collision: the human and vehicle end up at the same final speed v1f=v2f=vf.
Thus:
m1v1i = (m1+m2)vf
What we are concerned of is the ratio of initial vehicle speed, v1i, to post-collision speed vf. Your argument is that a lighter vehicle will have a larger drop-off in speed, recovering energy and reducing the severity of the collision. If you were right, the ratio v1i/vf should be less than 1.0, and be significantly different for a heavy and light vehicle. We will prove this wrong shortly.
Rearranging:
v1i/vf = m1/(m1+m2)
Already it is abundantly clear that when m1 >> m2, v1i/vf will be 100%. I will leave you no room for counterargument here by working two examples. Take the most popular pickup truck, the Ford F150, at 2125 kg. Take one of the smallest compact cars, a Honda Fit, at 1130 kg. Take the average adult human, at 65 kg.
For the F150:
v1i/vf = 2125/(2125+65) = 97%
For the Honda fit:
v1i/vf = 1130/(1130+65) = 95%
At 35 mph, that's a difference in speed delta of 0.7 mph, which is absolutely insufficient to explain the delta in injury severity presented in this article.
This proves what everyone knew all along: vehicle mass is insignificant in crash severity with a pedestrian because the masses of the two objects are so different. When the masses are similar (e.g. a small car colliding with a big car) yes, mass is important. But that's not what is being discussed and is not your argument.
I hope you go back to school and learn the basics before confidently acting superior. Take your downvotes and learn from this to do better.
The downvotes on this comment are a testament to the privilege of drivers. It's crazy how good people, who would otherwise not break the law, believe it's their right to speed. And before someone tells me it's a victimless crime I'll remind everyone that speeding kills both those inside and outside of your car.
Yes, this model has
Do you have a source on the production CO2 of an ebike? I'd like to see how they calculated the cradle to grave emissions.
The same paper addresses this directly. 86% of human beings live below this standard of living today.
Yes
I'm just bothered they chose divide by 3, instead of 16 seconds divide by 2 which is wayyy easier
Good article but this shouldn't be framed as a traffic ban. The street is not being closed for cars: it's being opened for people.
Best admin!
Without spoiling too much, do yourself a favour and read the Dune books haha. Hint: book 4 is titled God Emperor of Dune.
Btw there is no evidence of golden capstones ever being used on the great pyramids, and some good evidence against it.
Source for further reading? I'm also pretty invested in road design and I'd like to learn more about how it's done in Ontario.
Smyths
Thank you for being an amazing admin!
I know it from the tribute plaque to the Apollo 1 astronauts who sadly passed in a tragic fire during ground tests.
Same location, look for the tall white tower with the vertical stripes and balconies, which is in the middle of the bottom photo. Top photo is slightly more zoomed out.
BIIS
Is it your instance or my instance doing the censoring here? Scunthorpe effect at work.
At the risk of feeding the troll, here is the math you are suggesting we do, which disproves all of your arguments. It pains me how confidently you speak of a topic you are clearly so uneducated about: your physics mentors should be disappointed in you.
Conservation of linear momentum:
m
1v1i+ m2v2i= m1v1f+ m2v2fLet the vehicle be m
1and the human m2. Let the human's initial velocity be zero. Let us further assume an inelastic collision: the human and vehicle end up at the same final speed v1f=v2f=vf.Thus:
m
1v1i= (m1+m2)vfWhat we are concerned of is the ratio of initial vehicle speed, v
1i, to post-collision speed vf. Your argument is that a lighter vehicle will have a larger drop-off in speed, recovering energy and reducing the severity of the collision. If you were right, the ratio v1i/vfshould be less than 1.0, and be significantly different for a heavy and light vehicle. We will prove this wrong shortly.Rearranging:
v
1i/vf= m1/(m1+m2)Already it is abundantly clear that when m
1>> m2, v1i/vfwill be 100%. I will leave you no room for counterargument here by working two examples. Take the most popular pickup truck, the Ford F150, at 2125 kg. Take one of the smallest compact cars, a Honda Fit, at 1130 kg. Take the average adult human, at 65 kg.For the F150: v
1i/vf= 2125/(2125+65) = 97%For the Honda fit: v
1i/vf= 1130/(1130+65) = 95%At 35 mph, that's a difference in speed delta of 0.7 mph, which is absolutely insufficient to explain the delta in injury severity presented in this article.
This proves what everyone knew all along: vehicle mass is insignificant in crash severity with a pedestrian because the masses of the two objects are so different. When the masses are similar (e.g. a small car colliding with a big car) yes, mass is important. But that's not what is being discussed and is not your argument.
I hope you go back to school and learn the basics before confidently acting superior. Take your downvotes and learn from this to do better.
Survivorship bias?
You know what else pisses people off: the fact that speeding kills 33 Americans every day and permanently disables dozens more.[1]
The downvotes on this comment are a testament to the privilege of drivers. It's crazy how good people, who would otherwise not break the law, believe it's their right to speed. And before someone tells me it's a victimless crime I'll remind everyone that speeding kills both those inside and outside of your car.