how i foundout my car speed while sitting on the car

[drbizzarow]

hi 2 all
can anybody help me find car speed withhout using its speedo meter...
i know it can be done by ultrasonic speed finder but i want to know the speed of a car when im sitting on it not out side the car any matter wil be very helpful to me
thx in advance

 

[jamshid.dastur]

well seems your doing something adventurous...well what comes into my mind is mount a camera in front of the speedometer and have the screen on your lap outside the car...
Do tell us what are you up to...

Best Regards

 

[plusminus]

Maybe an anemometer will help. But if there is a wind outside you have to correct the value you meassure.

Or a pressure meter. You have to convert the pressure to speed.

 

[binu_ji]

By using a GPS in your hand you can get the speed from the GPS.

 

[funnynypd]

A Gyrometer?

 

[barrybear]

The distance between 2 lampposts is 50 meters. shorter in a built up area. time yourself between these 2 points and speed = distance divided by time

 

[Pavel_S]

Use accelerometers:

V(t)=V0+a*t

a - acceleration (+ or -)
t - time
V0 - starting velocity (=0 at the begining)

You can measure distance too:

\[S=V_0*t+\frac{a*t^2}{2}\]

A beginner's guide to accelerometers

 

[drbizzarow]

thx to all friends who guide me .......
im trying instal something in my car if someone drvie my car more the my set speed it start alarming etc

binu_ji & Pavel_S
..... im also thinking these to implement thse 2 idea ( GPS or Acelerometer). i think it will help to solove my problem. any comments on this idea wil be guide me more.
thx 2 all

 

[Kryptonite]

The distance between 2 lampposts is 50 meters. shorter in a built up area. time yourself between these 2 points and speed = distance divided by time

Is that distance standardized all over the world??

If not, where can I find such information for certain city or country??

 

[funnynypd]

thx to all friends who guide me .......
im trying instal something in my car if someone drvie my car more the my set speed it start alarming etc

binu_ji & Pavel_S
..... im also thinking these to implement thse 2 idea ( GPS or Acelerometer). i think it will help to solove my problem. any comments on this idea wil be guide me more.
thx 2 all

Some advanced GPS got similiar function for speed limit.
There is another way to do it yourself a gauge with speed limit function. This will depends what communication protocol your car has. Most of new vehicle after 1996 got OBD on board, such as K line, J1850, CAN etc. You will need more info.

 

[barrybear]

The distance between 2 lampposts is 50 meters. shorter in a built up area. time yourself between these 2 points and speed = distance divided by time

I am not shure about anywhere else but in England if you are in a built up area then the lamposts are closer together than if you are driving in a 40mile an hour area. Next time you are out see if this is correct.