Young man was walking down our road the other night, absorbed in his phone and meandering away from the side. I went by at 5mph over the speed limit, with plenty of clearance, and he threw his arms in the universal statement, “What the fuck?!”
Physics Quiz:
Annoying Anne is driving through a residential area at exactly the limit of 20 mph.
A child jumps into the street.
Anne reacts as fast as humanly possible and manages to stop the car right before she’d hit the child.
Normal Norman is driving through the same residential area at 25 mph, just 5mph over the limit.
A child jumps into the street at the exact same distance as before.
Norman reacts exactly as fast as Anne, and has the same car, tires and brakes.
How fast will Norman’s car be when he hits the child?
Answer
25mph
Explanation
Total stopping distance consists of reaction distance (how far your car travels while you react) and braking distance (how far your car travels while you’re standing on the brakes until it’s stopped).
The total stopping distance at 20 mph is shorter than the reaction distance at 25 mph.
Human reaction time is ~0.25 seconds.
At 20 mph, you’re going ~29 ft per second, so you go ~7.3 ft before you can react.
At 25 mph, that’s ~37 ft per second, so ~9.2 ft before you can react.
The internet says a good car can break at about 15 f/s^2.
At 29 f/s, that comes out to a stopping distance of ~28 ft.
At 37 f/s, that’s ~46 ft.
So Anne, who’s annoying for some reason, needs a total of ~35 ft to stop just before hitting the child.
Norman needs ~9 ft to start decelerating, so by the time he reaches the 35 ft mark (after ~26 ft of hitting the brakes,) it’s been a total of ~0.98 seconds, and he is going ~26 f/s, which is ~18 miles per hour.
it drives me insane when people argue that unprotected trafficants (translated from the swedish term because lazy) doing something wrong absolves drivers of all guilt, motherfucker the law very clearly states that it’s illegal to hurt people, context does not matter and if there is something you could have reasonably done to prevent or lessen the damage you are legally obliged to do it.
No one, least of all me, is arguing the pedestrian doing something stupid absolves the driver. Ever heard of the Darwin Awards? When you’re dead, it doesn’t really matter who was right or wrong.
5mph over is a quick walking speed. 25 vs. 20 sound terribly dangerous to you?
And it’s not like I barely missed the guy. We were well apart. Point being, he was mad at me because he had his head up his ass and wasn’t paying attention.
If y’all think it’s reasonable to walk down a dark street, head all up in your phone, go ahead. It is indeed the driver’s responsibility to dodge you.
Reminds me of my gf’s best friend back in the day. Drove like a maniac, dared anyone to hit her. “Fuck you! I’ll get a new car!”
And a lifetime of pain, or at worst, a Darwin Award. But hey! It was the other guy’s fault!
Again. You, driving the dangerous machine must avoid harming people. It’s not the pedestrian’s responsibility to dodge cars. 5mph is almost 10kmph which would make You lose Your license in some places in Europe.
Young man was walking down our road the other night, absorbed in his phone and meandering away from the side. I went by at 5mph over the speed limit, with plenty of clearance, and he threw his arms in the universal statement, “What the fuck?!”
Physics Quiz:
Annoying Anne is driving through a residential area at exactly the limit of 20 mph.
A child jumps into the street.
Anne reacts as fast as humanly possible and manages to stop the car right before she’d hit the child.
Normal Norman is driving through the same residential area at 25 mph, just 5mph over the limit.
A child jumps into the street at the exact same distance as before.
Norman reacts exactly as fast as Anne, and has the same car, tires and brakes.
How fast will Norman’s car be when he hits the child?
Answer
25mph
Explanation
Total stopping distance consists of reaction distance (how far your car travels while you react) and braking distance (how far your car travels while you’re standing on the brakes until it’s stopped).
The total stopping distance at 20 mph is shorter than the reaction distance at 25 mph.
Human reaction time is ~0.25 seconds.
At 20 mph, you’re going ~29 ft per second, so you go ~7.3 ft before you can react.
At 25 mph, that’s ~37 ft per second, so ~9.2 ft before you can react.
The internet says a good car can break at about 15 f/s^2.
At 29 f/s, that comes out to a stopping distance of ~28 ft.
At 37 f/s, that’s ~46 ft.
So Anne, who’s annoying for some reason, needs a total of ~35 ft to stop just before hitting the child.
Norman needs ~9 ft to start decelerating, so by the time he reaches the 35 ft mark (after ~26 ft of hitting the brakes,) it’s been a total of ~0.98 seconds, and he is going ~26 f/s, which is ~18 miles per hour.
Well being the driver You are the one responsible for not hitting the pedestrian. So speeding next to a pedestrian at night makes you an asshole.
it drives me insane when people argue that unprotected trafficants (translated from the swedish term because lazy) doing something wrong absolves drivers of all guilt, motherfucker the law very clearly states that it’s illegal to hurt people, context does not matter and if there is something you could have reasonably done to prevent or lessen the damage you are legally obliged to do it.
No one, least of all me, is arguing the pedestrian doing something stupid absolves the driver. Ever heard of the Darwin Awards? When you’re dead, it doesn’t really matter who was right or wrong.
5mph over is a quick walking speed. 25 vs. 20 sound terribly dangerous to you?
And it’s not like I barely missed the guy. We were well apart. Point being, he was mad at me because he had his head up his ass and wasn’t paying attention.
If y’all think it’s reasonable to walk down a dark street, head all up in your phone, go ahead. It is indeed the driver’s responsibility to dodge you.
Reminds me of my gf’s best friend back in the day. Drove like a maniac, dared anyone to hit her. “Fuck you! I’ll get a new car!”
And a lifetime of pain, or at worst, a Darwin Award. But hey! It was the other guy’s fault!
Again. You, driving the dangerous machine must avoid harming people. It’s not the pedestrian’s responsibility to dodge cars. 5mph is almost 10kmph which would make You lose Your license in some places in Europe.