If a car is going 50km/hr and stops in 0.3km, how long does it take the car to stop?

If a car is going 50km/hr and stops in 0.3km, how long does it take the car to stop?

Linear deceleration? Ignore effects of friction, aerodynamics etc.?

>stops in 0.3km
>how long does it take the car to stop?

I'd say 9292,4km

>Ignore effects of friction, aerodynamics etc.?
>implying any of that matters

it will take at least 21.6 seconds.

twice the time it would take to drive the 300m without stopping

Of course it does. The way a car breaks is heavily dependent on its tires and its shape.

About 0.3 km

~1.19882076 s

I think it's 43.6 seconds
what am I doing wrong here?
is the half obsolete?

43.2*

Let's say the car halves its speed until it gets to 0.150 km then halves that speed until gets to 0.175km, then halves that speed until it gets to... etc

The car will never arrive at 0.3 in finite time

yup
you know:
s=a*t^2/2
and:
v=a*t
juggle:
a=2s/t^2
a=v/t
subtract:
0=2s/t^2-v/t
juggle:
v/t=2s/t^2
v*t=2s
t=2s/v=43.2 s

144 seconds

But if the car drives 0.1 km then 0.2 km then 0.3 km etc, it will have stopped 0.008333... km behind where it started

so it IS 43.2 seconds? I don't see anything wrong with my calculations

Bout tree fiddy

yes

>implying it doesn't
a car could crash-brake to 1 km/hr as quick as it possibly can and then bleed off velocity as slowly as it can before it stops at 0.3 km

or it could crash-brake at the last possible second

or it could uniformly decelerate

all of those will have different times

But already specified "linear deceleration", which takes care of all that variability.

>its a OP baits with a vague problem, that has multiple right solutions episode

1 plank time.

Enjoy your destroyed universe, faggot.

v=50-(50/T)t
d=50t-(25/T)t^2+C
0=50(0)-(25/T)(0)+C
0.3=50T-(25/T)T^2
T=0.012 hours = 43.2 seconds

YOU GUYS ARE SO SMART WITH THIS KINDERGARDEN TIER PROBLEM.

>KINDERGARDEN

you either need to know calculus or use the disassemble acceleration in the third standard formula

You don't need to know calculus to find the area of a triangle.

you need it to know that the integral of velocity is acceleration, and that the area under a curve is the integral

Doesn't matter, this "level" of calculus is for 15yo kids.

>linear function
>curve

what did he mean by this?

That post at was asking whether to assume linear deceleration, not specifying it.

nice job spelling kindergarten wrong

>the integral of velocity is acceleration
Forgot to mention, this proved my point
>kindergarden thread

Fuck spelling in foreign languages

this question is too hard
is it 100 seconds?
what is acceleration anyway if not a figment of our imagination

acceleration doesnt exist except in our minds