for all you smart people(math help needed!!!)

[footballjds]

Hello.

I have been given an assignment that i cannot fathom how to do!!! :p

i would like some help, its math that I've not done yet.. :p
here is the problem(btw, its due tomorrow morn)...

okay. so here it is:

We have an axle with a wheel at each end. the axle is "x" units long, the wheels have a radius of "y" units and the angular volocety is (z*r)/s (where z is how many and r is radians. so if z where 12 it would read 12 radians per second.)

now i want to make a point turn. (turn in place) to do this the one wheel must go backwards and the other one go forwards. i want to make a 90(right) degree turn.

now given this i need to make an equation/formula that tells me the time in seconds it will take to make a 90 degree turn.

the here is all the variables again(things that will effect the turning time)
the distance between the two wheels(axle's length), the circumference of the wheel(which will be calculated by plugging in the radius in the equation 2*pi*r) and finally the angular velocity(radians per second).

thanks for taking the time to read this far. :)
all help is nice!!! :)

[Taylor]

Stop spammin meh phone with this!

Joking, it's fine. I honestly don't know though :o Good luck finding out :s

[footballjds]

one send = spam. :p??
please post helpful things. what you said is spam[/jk]

[apx900]

bloody hell looks complicated, unfortunaly i'm not any good on 3d geometry, 2d i can deal with. i'll see if i can find someone who does.

[footballjds]

thanks for trying to find someone :D

[Naum]

thanks for trying to find someone :D

You need someone with the intellect to match BenLand on this one ;)

[footballjds]

well go stir him into action p10x ???

lol :P

[apx900]

http://en.wikipedia.org/wiki/Wheel_and_axle

that might help. the rope on the pic is the circumferance part(by the axle).
still got the other geezer working on it.

[MylesMadness]

Why would I know this... im 12...

[nielsie95]

I'm not entirely sure, but this is what I've come up with:

The wheels turn in a circle with the diameter of the axle, right?
That means that the radius of the circle is x / 2. For a full turn, the distance the wheels travel equals the circumference (I hope I used the right word here). So for a 90 degree turn that would mean (2*pi*r)/4 = 0.5*pi*r. The radius of the circle was x / 2, so that would make .025*pi*x for a 90 degree turn (distance the wheel has to travel).

A wheel can travel its circumference, so that's 2*pi*y for one rotation. It has to do (0.25*pi*x) / (2*pi*y) = x/(8y) rotations.

1 rotation of the wheel takes (2*pi)/z seconds.

So if we combine those, I get x/(8*y) * (2*pi)/z = (pi*x)/(4yz).


That's how I got there. But, as said before, I'm not entirely sure (it's quite late too :p). I also hope you understand what I did (it's a bit hard to explain in English).

[apx900]

Sorry my guy came up empty handed. but what he did say was:

Hi Ahmed

Nots familiar with that equation although the following is what relates to Angular velocity if thats any help


v= w*r gives a 360 degree turn then divide by 4 to give a 90 degree turn, so,

v= w*r / 4 * x

Not much help sorry

Martin

Where:
ω - angular velocity (rad/sec)
v - tangential velocity (in/sec)
r - radius (in)

[footballjds]

I'm not entirely sure, but this is what I've come up with:

The wheels turn in a circle with the diameter of the axle, right?
That means that the radius of the circle is x / 2. For a full turn, the distance the wheels travel equals the circumference (I hope I used the right word here). So for a 90 degree turn that would mean (2*pi*r)/4 = 0.5*pi*r. The radius of the circle was x / 2, so that would make .025*pi*x for a 90 degree turn (distance the wheel has to travel).

A wheel can travel its circumference, so that's 2*pi*y for one rotation. It has to do (0.25*pi*x) / (2*pi*y) = x/(8y) rotations.

1 rotation of the wheel takes (2*pi)/z seconds.

So if we combine those, I get x/(8*y) * (2*pi)/z = (pi*x)/(4yz).


That's how I got there. But, as said before, I'm not entirely sure (it's quite late too :p). I also hope you understand what I did (it's a bit hard to explain in English).
thanks a ton. i followed along but read fast. i think this is good. but ill work it out and find out :) you don't have it right totally but :p
should be a start...

Sorry my guy came up empty handed. but what he did say was:

that's helpful :)
cause i forgot that angular voracity equation :p

btw this is still up if someone finds out THEE WAY :D
please respond fast if u do as its due in like 11 hrs :p