Question about rear view mirrors

[netnarc2]

The right side (passenger) mirror on most cars has a notation "objects in mirror are closer than they appear" or something similar to that. I know that they are closer than they appear, but why is the right hand mirror different from the driver's side mirror? And why didn't the manufacturers just put regular rear view mirrors on the passenger's side? I know it sounds like an Andy Rooney question, but it seems stupid to have a mirror that doesn't repsresent true distances. Anyone know why?

 

[KOPBET]

I'm not an engineer, but I play one on TV. My opinion on this is the mirror is built this way to increase the field of view and reduce blind spots. Since many mirrors tend to be the size of a peanut, every little bit helps us old people. Just my view.

 

[vettepilot]

The right side mirror is convex shaped, designed to give a larger field of view, this helps reduce or eliminate the blind spots on the right side of most vehicles. When adjusted correctly, one can also see several lanes of traffic such as that which might be encountered on freeways and interstates.
vettepilot

 

[netnarc2]

Thanks. That makes sense.

 

[KOPBET]

Found this link...

http://www.physlink.com/Education/AskExperts/ae449.cfm

 

[netnarc2]

KOPBET, thanks for the link. I'm going to bookmark it for future use.

 

[jbaker]

Ok, while on the subject of rear view mirrors, explain why they shake so much (just the glass, not the assembly) when you hit a bump??? Can it be fixed?

 

[vettepilot]

I'm assuming that your wondering about the outside mirror(s)?
If so, and this is more educated guessing than real knowledge.
The mirror assembly has two motors, one to tilt the mirror glass up and down, the other swings it left and right. Because there are small gears or worm drives involved, (which ever doesn't matter, the result is the same) there will always be a very small amount of free play in the mechanism, additionaly the drive mechanism is probably made out of nylon or a similar material, which, is not the most structually stable material when molded into small parts and components. It is this freeplay that allows the mirror to move slightly whenever a bump is transmitted up through the body to the mirror support, and eventually to the mirror itself. In fact, if you gently try to move the mirror by hand, you will be able to detect this freeplay.
Now if there is somebody out there with actual (read factual) knowledge on the exact mechanism setup, please feel free to jump in and either correct me or let me know how close I came.

vettepilot

 

[jbaker]

If you have a road that shakes the mirror's THAT much..............I'd stay off the road. :L

I'd have to agree with vette pilot. The trunion the mirror is attached to does have a little "play" in it. To the best of my knowledge, having had to replace the glass and seeing "inside", there is no way to tighten it.

Len

Nah, roads aren't THAT bad around here, I'm just talking about a little shake that makes the image look blurred... It's not like the thing is wobbling around in there.... Just wondering if there was a way to make them rock solid..

 

[Heyspike]

Objects closer then they appear---It's to remind you the the girl sitting next to you is very, very close, so be careful what you say