Can you stop a car if...?

Dave

No.

Most people can't run 20 mph so there's no way from behind a car to just hop down and drag your feet. You'd end up toppling head over heels as soon as you hit the ground.

From in front, you'd just get run over.

And certainly don't try it, someone will just get hurt or worse.

And if the engine were on and the car in gear, you can't stop it at all, even it were going only a few miles per hour, much less 20 mph.

klaus baudelaire

whatz a adrenaline????

john d

My 51lbs son can stop a 36000lbs car in 2 seconds flat. it is cald power breaks. and that is the real question is it not?
no adrenaline required!!!!
and by the way if a car backs you up against the wall and you stop it. it is the wall that will stop the car and whatever is left of your legs

This is a Physics question not an automotive question.
To accelerate a 1000lb car at 1g (32ft per second per second aka 1G) it would take about 100hp at the instant you started. By the end of the first second it requires about 400hp (this is why you cant travel at the speed of light, sooner or later you reach the infinite power required for acceleration). Deceleration is exactly the same thing in reverse. So if a 200 lb man/woman wanted to stop a 1000lb car traveling at 30mph (44ft/sec) and we ignore the energy required to ever-come the static energy, and the energy dissipated in bending metal and breaking bones. The answer would be the person would have to generate more than 300HP at the collision and dissipate that energy for about 2 seconds with a final HP out put of 0 HP. Now the average donut eating person can sustain about 1/8hp for about 10 min and spike at about 1/3hp for a few seconds. The big boy professional athletes can sustain 1/4hp all day long and using there mass can generate as much as 15hp for a few milliseconds. Now lets just take some insane numbers and say that a heart-exploding burst of energy can boost the HP of an athlete by a factor of 10. That means that their output would be 150HP.
So just by the 1000lb car hitting the 200 lb guy the car would slow down to 24mph. The HP requirement would be about 360 to stop the car at 1G that means that if his arms and body leans it to the collision the car would run over the guy at about 20MPH. But then again we are talking about a what if and maybe question, with a very light car and muscle bound 200lb guy. In reality a person can stop a million pound train traveling at 99% of the speed of light but it takes a very, very, long time like about 10 or 12 million years.
Remember that these numbers are just off the top of my head and that there was no calculations involved, but they are close enough to demonstrate the point, and I bet that the HP requirements for acceleration are very very close +- the drag coefficient of the vehicle that is actually left after transmit ion, drive line and other losses. The actual HP output of a human being are also close enough to demonstrate the point
and by the way, if an athlete can run 100m (333ft) in 10 seconds flat there average speed over the run is 22.7MPH after they eccelerate from 0mph, that means they re top trotting speed is like what, 25mph or better?????
60MPH = 5280ft/min= 88ft/second, 30MPH = 44ft/second and 22.7MPH = 33.3ft per second a human can to run 20MPH but i dout that I could make 15 for 40yrds maybee 20yrds
the amount of energy to stop a car from 30mph is like what 1 big mac?

gulfbreeze8

Turn the ignition off. If that doesn't help, put it in reverse.

Edwyn

Im sure theres a way but it might be dangerous

chewalter

No, you can not
Imagine this: A 30mph crash can propel an unbelted 60lb child with a force of about 2700lbs
It is like that child, is now an elephant. Do you think you can stop it?

bluesmozis

No you can't!

speed=distance/time traveled.
a= variation of speed over times(how fast you want it to stop)
Force per second=mass of car * acceleration
Since you could take all day slowing down the car yes you can stop the car physically.

But the real question is, can you run 20 mph!
And the answer is no...

or Is the car going up a hill?...lack of info.

Bill P

Try it out and gt back to me

palestinian

bungee

prE4chEr

i think so. but only from behind. like you grab on and drag your feet. but only if it is just rolling, not if someone is giving it gas. and if you try to stop a car from in front of it you probably will break your legs, among other things.

UCANTCME

NOOOOOOOOOOOOOOOO.

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