Anyone good at Maths?
Turbo Mini Forums

Hi,

Got a uni problem that im struggling with a little.

I have to work out the distance a parked car should be away from a pedestrian crossing so as to not obstruct the view of the driver to see a pedestrian on the pavement. So its using trig to work out, obviously using the stopping distances of the car for distance from the crossing (12.11) and a rough estimate how far the car is out when driving (4.27) and then how far the parked car would be out (2.01) I have attached a quick diagram but does anyone know how i would work it out? I need to express the answer as a equation to just plug in the road speed and get the distance?

I could work out the angle and then using the 2.01 work out the missing length but this does not seem right, and also how would i express it as an equation?



Cheers

Jon

It sounds like you need to use standard kinematics formulae etc, ie v=u+at , v^2-u^2=2as etc but i'm not 100%.

Edited by t3gav on 27th May, 2009.

lots of variables in this. height and width of the obstructing vehicle, height and width and driving position of car needing to stop, road surface type ie. is it that extra sticky stuff they usually put near crossings. or am I thinking too real world?

From what i have looked at it only needs to be simple, i.e. overlooking things like skidding, weather etc and just use the figures given, if you see what i mean.

Cheers

Jon

Have you been given any constants etc? Otherwise how are you going to know the stopping distance?

Hi,

Yeah we have been given an equation for stopping distance and a couple of constants to work this out. I have working it out for 20mph which is 12.11m.

At this point i then worked out the angle in the triangle as you know two of the three lengths of the triangle.

Then with this angle, and the opposite length being the width of the parked car i hoped to work out the legnth of the adjacent side giving the distance the car needs to be away without interupting the line of sight. Im not too sure im doing the right thing though??

Cheers

Jon

Yep that sounds right, just right it as a formula though as the distance eg x will always differ.

It has to be parked outsisde the white zig zag lines.....go check the highway code lol.

9.85 @ 145mph
202mph standing mile
speed didn't kill me, but taxation probably will