Welcome Guest ( Log In | Register )

Outline · [ Standard ] · Linear+

 How to estimate a car's acceleration?, got formula?

views
     
TSallornothing
post Feb 18 2007, 04:54 PM, updated 18y ago

Melancholic //
*****
Senior Member
926 posts

Joined: Feb 2006
From: KL, Malaysia


Let's say a car with 100hp. Weighs 900kg and has a torgue of 120nm. Is there a way to calculate the acceleration?
jason18689
post Feb 18 2007, 05:13 PM

[xx Years @ LYN]
*******
Senior Member
3,681 posts

Joined: Nov 2005
From: -


u drive for 5 seconds...
and tell me what is the speed when
a)0second
b)5seconds

then i can calculate...lolx
a = v-u / t
LarharT
post Feb 18 2007, 05:22 PM

It's not the end of the Road Yet
****
Senior Member
608 posts

Joined: May 2005
From: Penang Island


QUOTE(jason18689 @ Feb 18 2007, 05:13 PM)
u drive for 5 seconds...
and tell me what is the speed when
a)0second
b)5seconds

then i can calculate...lolx
a = v-u / t
*
lol...Physic formula
tunertoobe
post Feb 18 2007, 06:06 PM

Look at all my stars!!
*******
Senior Member
9,309 posts

Joined: May 2005
From: Sabah-Australia-Shah Alam.


Yes there is a way but I think after ignoring other factors(such as drivetrain losses, aerodynamic drag, gear ratios, assuming you have infinite traction, etc.) it's still quite complicated.
I dunno the exact formula, any Physicians here? biggrin.gif I'm interested also.
The horsepower number can be ignored. Horsepower IS torque and torque is work. Horsepower is just work at a certain time(rpm) so you see we don't really need it.
zombie
post Feb 19 2007, 05:22 AM

Died
****
Senior Member
684 posts

Joined: Jan 2003
From: MY
Accelaration does not care about what drive train, torque or what nots.

jason18689 has already given you the formula.

So, use it lar. doh.gif
TSallornothing
post Feb 19 2007, 09:05 AM

Melancholic //
*****
Senior Member
926 posts

Joined: Feb 2006
From: KL, Malaysia


ok ok. but can you explain the formula? I don't study physics.. sad.gif
karhoe
post Feb 19 2007, 09:12 AM

Look at all my stars!!
*******
Senior Member
6,238 posts

Joined: Sep 2005
From: Kuala Lumpur


QUOTE(allornothing @ Feb 19 2007, 09:05 AM)
ok ok. but can you explain the formula? I don't study physics..� sad.gif
*
lets say you accelerate for 5 seconds

V - final velocity - at the 5th second, look at your speed meter
u - initial velocity - at your beginning of acceleration

t - time taken for change of velocity

hence apply the formula of rate of change of velocity / acceleration

(v - u) / t

This post has been edited by karhoe: Feb 19 2007, 09:13 AM
LEVIATHAN
post Feb 19 2007, 10:04 AM

Master Chief Carl M. Brashear
*******
Senior Member
2,281 posts

Joined: Oct 2006
From: Littleroot Town



mate,
just hit the gas. count to 5. see the speedometer. read it at count 5. divide by 5. done. haha. crude example it is. just set a countdown for example 10. start countdown as u hit the gas. read the speedo when the countdown ding dongs. divide the seen speedo by 10.

edit: assumed u start from 0 tho.


This post has been edited by LEVIATHAN: Feb 19 2007, 10:05 AM
tunertoobe
post Feb 19 2007, 11:04 AM

Look at all my stars!!
*******
Senior Member
9,309 posts

Joined: May 2005
From: Sabah-Australia-Shah Alam.


I thought he asked how to calculate the car's acceleration from the power/torque alone? blink.gif
If its that simple v-u/t formula, why did you mention the torque? Sorry I was mislead. laugh.gif

Yes there are methods to calculate the car's estimated acceleration without you having to step in the car at all, but strictly for advanced university students. laugh.gif

This post has been edited by tunertoobe: Feb 19 2007, 11:06 AM
musha01
post Feb 20 2007, 06:09 PM

Getting Started
**
Junior Member
207 posts

Joined: May 2005


wah difficult ,no other easy technic
BridgestoneRE711
post Feb 25 2007, 03:06 AM

♦ ♣ ♥ ♠
*******
Senior Member
3,429 posts

Joined: Nov 2004
From: alor star • selangor • skudai


no technique . all enigne power band at different peak ... how to estimate .
ur enigne is not chunking out 120bhp all in its rpm range from 0 until 6000 .
tunertoobe
post Feb 25 2007, 11:01 AM

Look at all my stars!!
*******
Senior Member
9,309 posts

Joined: May 2005
From: Sabah-Australia-Shah Alam.


That's why it isn't easy. There is a way, but I think no exact formula. The end result, no matter how much outside factors you consider in your calculation, would still be an estimate.
You have to know the power curve, the power band, the weight, how much grip you have(unless you assume you have infinite grip), aerodynamic drag(unless you exclude that), gear ratios, transmission loss(again optional), time lost in shifting, clutch slip, bla bla bla bla bla.
kev da man
post Feb 25 2007, 11:11 AM

super lurker
********
All Stars
15,278 posts

Joined: Jan 2003


want to estimate the cars acceleration without formulas? get a satellite system tongue.gif

 

Change to:
| Lo-Fi Version
0.0152sec    0.26    5 queries    GZIP Disabled
Time is now: 29th March 2024 - 02:51 AM