Well, I just got locked out, just before I tried something I came up with... I just emailed the teacher to see if I can get another few tries... ugh :( thanks anyway

whatd you try?

I tried using Velocity Final squared is equal to Velocity Inital Squared plus two times the acceleration times displacement.

I got 0= V initial squared + 2(-10.0)(34.04)
V initial squared = 680.6881
V initial = 26.09
It didn't work... or maybe I'm doing it wrong...

hmm well your lookin for the max velocity he can go right?

88 km/h = 24.444444444 m/s

so first you figure out how much distance his reaction takes (0.75s)

d = (v)(t) -> d = (24.4)(0.75) = 18.3m til he hits the brakes leaving 19.7m to stop yes?

Why are you guys doing this kid's HW?

i ... dont ... know .... lol but now i wanna know the right answer

I came up with 88km/h as something else in m/s...

I multiplied 88 by 60 to get km/s and then divided by 1000 (that's my error... I should have multiplied by 1000 to get m/s) but then I get something ridiculously huge... if I divide, I get 5.28 m/s and then multiply that by .75 and subtract the product from 38.0 to get 34.04m as the distance from when he starts to brake...

km/h -> m/s

x1000 then / 3600

So this proved you all suck at physics.

why 3600?

6.023 x 10^23

why?

Physics, not chemistry! Avogadro's number isn't going to help me!!

he would end up in jail. speed limit is only 65.

:nod:

because you haven't come up with the right formula yet, which means if you do hit the answer (by some means, perhaps the russian's beaming method) it will be by pure luck, not because you have applied the right formula.

that's all physics is unless you are among the elite - then you get to try your own formulas and spend years proving/disproving them, supported, of course, by educational grants from the government and wealthy privateers... applying the right formula.

No, the answer is 19.67 m/s. I posted Avegadro's number because I felt like busting balls- as he should really do his own homework so he doesn't get boned on a test.

I got it the same way 97Camaro did. 18.33m covered until the brakes are applied, 19.67m of distance left, equation will zero out when the initial velocity is ~19.83m/s. The only "ball buster" is how far they want the car to be from the wall to be considered "not hit". 0 is not really right IMO, because they would be exactly touching.

So 59 is NOT the answer? :?:

No?

orly? i used my cheat sheet from physics last year with all the kinematic equations and those are the 'right' formulas

Oh man, I'm so disappointed!

LOL. I used the exact same website. Couldn't remember most of them.

Did not figure in speed of light, fail.


:wink:

If you want we can help you determine the electrical resistance of a dead fuel pump.

Prob pretty high. I would guess more than enough to melt those puny wires that feed it.

wait, what motor?