Need some math/automotive speed help

[Chew]

This has come up in a cold case that we are working on. I suck at math and it's probably just a matter of figuring out a feet per second formula but I have a headache.

I researched and found the following info on a vehicle in reference to it's acceleration rates:

1/4 mile time is 19.2 seconds
1/4 mile speed is 72 mph

Can someone figure out how fast the vehicle could possibly be going within 519 feet if it started from a dead stop?

Thanks.

[CabezaBlanca]

What type of vehicle are we talking about?

Never mind. One that goes...

1/4 mile time is 19.2 seconds
1/4 mile speed is 72 mph

[Dale Moser]

The acceleration rate is not a straight line figure, but a curve. It's not gaining speed at the same rate at the end of the 1/4 mile that it does at the beggining. I'd bet 32-35.

[Quackerbox]

Easy peasy.

Email traffic. [emoji3]

[Rubi513]

28.3

[Chew]

This may help:

[Chew]

Easy peasy.

Email traffic. [emoji3]

Good point!

[lab man]

28.3

[Quackerbox]

Good point!

I bet meaux could Cipher that in less time than the email took.

[Chew]

Thanks guys. Can you tell me how you came up with 28.3 ?

[CabezaBlanca]

72 ÷ 1320 x 515 = 28.09

[Chew]

OK. THanks. I'm thinking that the acceleration rate/bell curve or whatever would affect it (car goes faster at certain points/gear ranges during the acceleration cycle). What do y'all think?

[Rubi513]

It won't be exact, but more of an average.

1/4 mile = 1,320'
72mph/1,320 = .054545454 mph per foot
.054545454 x 519 = 28.3

[CabezaBlanca]

OK. THanks. I'm thinking that the acceleration rate/bell curve or whatever would affect it (car goes faster at certain points/gear ranges during the acceleration cycle). What do y'all think?

Exactly. There's no way to know the exact speed. But I would guess by your chart you could tell how fast it wasn't going.

[Jaybo31]

OK. THanks. I'm thinking that the acceleration rate/bell curve or whatever would affect it (car goes faster at certain points/gear ranges during the acceleration cycle). What do y'all think?

Yes. I dont think its as simple as the formulas posted giving 28. 28 is figured with a constant over the 515 but the acceleration is not a constant so it will be different.