help Veeky Forums!
I know the car's mass and the engine's power, how do I find its acceleration?
I know that:
P=Fv
So it should be a simple proportional relationship... but what is that "v" term doing there? Is that the velocity of the car? The velocity is zero at time t = 0, which would give me a division by zero if I try to solve for F.
Oh and this is all neglecting friction, air resistance, etc... and car's on a flat surface so gravity not a factor.
Go to your instructor not us
we are not pre-college homework help
the car would have a power train with really complex mechanical properties
v would be proportional that the mass has to horse power
So m >= hp/f or the car wouldn't run
Sure, then take the "200 hp" number as the power delivered to the wheels. And this:
>neglecting friction, air resistance, etc
means that it's all converted to acceleration.
what?
Not homework. Most "pre-college" teachers don't draw homework problems in MS Paint. And normal people call it "high school," numbnuts.
a real car it would shift gears. Good luck figuring that shit out
Some people, when they want quick answers, will redraw something in MS paint because it only takes like 30 seconds
compared to the relative 5 minutes they could spend looking for an answer
boump
Did you pay Elon the $10k upgrade for "ludicrous speed?"
There are a lot of variables you are omitting here, user.
>Veeky Forums takes on a middle-school-level dimensional analysis problem
In a real (not ideal) car, power (P) is a
complicated function of the car's velocity (v)
involving the engine's power curve and
the drivetrain gearing.
The accelerating force (F) is always
limited by the friction co-efficient (f)
of the tyres, so that F ≤ Nf,
where N is the normal force (weight)
on the drive wheels.
Ok, so throw out the friction and assume the power is constant and no gears. 200 hp straight to the wheels. What's the force?
6
I don't know why you're getting dicked around here.
Consider P=Wt, and use the work energy theorem to note that
W=Delta-E (gonna use E for kinetic energy here).
Then recall that E=1/2(m v^2).
So if power is constant, energy is increasing linearly with time and so velocity is increasing linearly with time.
Additionally, with P*t = 1/2 mv^2 we get
v = Sqrt(2*P*t/m)
Acceleration can then be found through differentiation.
Acceleration isn't constant though, which is the error that's caused you so much difficulty.
Why the fuck does this fucking retarded site think this is spam?
Ayyyyy thanks.
And then I can find F through F = ma.
>I don't know why you're getting dicked around here.
Welcome to Veeky Forums
>velocity is increasing linearly with time
>v = Sqrt(2*P*t/m)
wat
You can do LaTex directly in the post with tags.
[math]\Delta E = \frac{m \left ({v_f}^2 - {v_i}^2 \right )}{2}[/math]
What exactly did you think the text in my post meant?
man what's with those units
Americans are fucking retarded
200hp wtf? that's like medieval shit
Yeah, my bad. That was stupid.
It's not part of any normal American curriculum.