Mathematical riddle

[Tobe2be]

This was given to me by my math professor in college and it took me a while but i got the answer and i thought i would share it with AO. here we go

there are 9 quaters all the same size and all look the same but one is fake. the fake weighs less than the real ones. you have a balance type scale. you can only use it twice to find out which one is the fake coin. and YES its possible. ima post answer in about 2 days and then post the other part to this riddle that is a lil bit more difficult.

just in case people dont know what type of scale im talking bout its this type


EDIT after Q bashing me in the chat i will add this to the riddle you can only use the scale to find the fake coin... HAPPY!?!?!

[tribalman]

take four of them and place them in the left, 5 in the right. if the right one is heavier by a lot, then it's the the left. if the right is only slightly heavier its in the right one.

if it was in the left, take out the 5 and set them aside. take the 4 remaining and take one out and set it aside, put 2 in left, the last in the right. if they are about equal........bah, i actually can't remember after the first step, oh well, if i remember, i'll edit the post. i back away...hope this can strike a thought in some1 else's mind

[Tobe2be]

wrong... please dont ruin this for eveyone if you want to know if your answer is right contact me thru pm or chat i will tell you. thanks

[lopxtc]

***EDIT***

Sorry didnt mean to post the answer .... sent it to you in a PM.

BTW this one is super easy .... hope your harder one is hard

Aaron

[Hamster Huey]

College was a while ago, but let me give this a stab. Seems like a fun problem.

***answer edited out***

Whoops - didn't know you didn't want peeps to post suggested answers.

[Tobe2be]

pm sent to the correct answers. i think ima make it 1 day before answer then new problem

[bofh]

ah that was fun.

Good luck guys.

[Tobe2be]

bofh was the first one to have both parts solved.. bofh is a fart smella.. i mean smart fella

[bofh]

OK, here's a fun little riddle for first year physics professors. Or high school physics teachers.

One of the things they teach in basic physics is that friction is not dependant on surface area, and is solely a function of pressure(ie. force, weight, whatever term makes you happy.) and the properties of the materials..

So if you have a pound of force pushing on a pin head or a square foot, the force to move it sideways is the same.

^ this isn't the riddle part, this is the background info.

So the riddle is... why are sportscar's tires wider than normal tires?

[mcveighr]

The scale one is easy. It probably would be a bit more difficult if people didnt tell it all the time.

[Tobe2be]

ok keep waiting the second part will be posted tomorow night... feel free to post other riddles involving some logic/math

[Miscue]

1 step solution:

Put quarters in one of the pans. Rotate the pan quickly, but not enough to throw the quarters. The quarter of a different weight will be at a different height.

Yes, it specifies that it is a math problem. But physics = applied mathematics.

[Miscue]

OK, here's a fun little riddle for first year physics professors. Or high school physics teachers.

One of the things they teach in basic physics is that friction is not dependant on surface area, and is solely a function of pressure(ie. force, weight, whatever term makes you happy.) and the properties of the materials..

So if you have a pound of force pushing on a pin head or a square foot, the force to move it sideways is the same.

^ this isn't the riddle part, this is the background info.

So the riddle is... why are sportscar's tires wider than normal tires?

Heat dissipation. More tire = distributes the energy/heat created from friction into a wider area. If a tire is too cold or too hot it results in a lowered co-efficient of friction... because the frictional properties of rubber change depending on temperature.

[trains are bad]

last longer too.

[RenagadeOfFunk]

...i got the coin one...