Topic: Fastest 1/4 mile

[Markcb750]

 




funny stuff here

[sangyo soichiro]

Your problem as presented is a kinematics problem, friction would not play a part in it.

Have you ever tried to drag race on ice...?   

[Duke McDukiedook]

Without giving the mass of the vehicle in question your problem is a kinematics problem.

Friction and mass plays no part in the way you worded it.

[sangyo soichiro]

Without giving the mass of the vehicle in question your problem is a kinematics problem.

Friction and mass plays no part in the way you worded it.

But...
but...
...but I gave the solution....   

And I made use of one of the kinematic equations...
and in order to find the answer, I had to use the equation for friction...
and I'd bet Markcb750 did too...
and when you equate friction to Newton's 2nd law, the mass cancels out...
(and I'd bet if you actually read the solution, you'd see this....)

I have a hunch you're pulling my chain....   

[Duke McDukiedook]

Friction would only play a role stated in your problem if you gave the mass of the vehicle.

Otherwise 'a' is simply 32.2ft/s^2. You stated a kinematics problem like I said before.

If you gave us the mass of the vehicle, then it becomes a dynamics problem.

[sangyo soichiro]

Friction would only play a role stated in your problem if you gave the mass of the vehicle.

Otherwise 'a' is simply 32.2ft/s^2. You stated a kinematics problem like I said before.

If you gave us the mass of the vehicle, then it becomes a dynamics problem.

32.2 ft/s² is g. 
'a' is Shirley's acceleration down the track.

I didn't need to give the mass of the vehicle because it cancels out quite nicely.

Look here:
f = mg(mu) = ma
        g(mu) =   a     

I guess you could say that we implicitly (as opposed to explicitly) used the mass in the calculation. 

[Duke McDukiedook]

Kinematics- Uniform acceleration, t = 9.05s

Static friction factor plays no part in your word problem.

[sangyo soichiro]

Kinematics- Uniform acceleration, t = 9.05s

Static friction factor plays no part in your word problem.

So you're saying that the best possible time she could have is 9.05 seconds...?

But Shirley's actual time was 4.97 seconds....



She was driving the car down a track, not off a cliff.  Your number is the time it takes for an object to fall a quarter of a mile.


Oh... you joker you.  Didn't think I'd catch it did you? 

[754]

So what came first, ?

Shirley's Rail..?

or.. the Formula ?............Cha..Cha..Cha...