Formula for this ?

Each tire on a car has a radius of 15 inches. The tires are rotating at 400 revolutions per minute. Find the speed of the automobile to the nearest mile per hour.

Question

Formula for this ? 

Each tire on a car has a radius of 15 inches. The tires are rotating at 400 revolutions per minute. Find the speed of the automobile to the nearest mile per hour.

ikram002p · Answer

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ikram002p · Answer

now u can see the the one revolution = the circulm of one tire.

ikram002p · Answer

post that the speed =distance/time

yamyam70 · Answer

aha...

ikram002p · Answer

got it untill now or still confused ???

yamyam70 · Answer

I'm getting you. :)

yamyam70 · Answer

This is somewhat I think, linear speed,

ikram002p · Answer

its count  circuler speed but the qs want u to convert it to linear speed 
ok now apply the form pefor
speed =400 revolution ,, but u need to convert revolution to distance / miniute

yamyam70 · Answer

I'm not getting you .. :/

ikram002p · Answer

speed=(400*circumference ) inches/minute
find circum. 
now where u exactlye stuck??

yamyam70 · Answer

one moment..

yamyam70 · Answer

the question is asking for, mph, so... I should multiply it by 1 / 60 ?

yamyam70 · Answer

I'm also thinking of, converting 400 rev / min to radians  ,

ikram002p · Answer

u should do that at the end but first u need to covert the distance , but i think got the trick

yamyam70 · Answer

by the way, is this angular speed or linear speed?

yamyam70 · Answer

both   ?

yamyam70 · Answer

can you explain this to me again step by step? :)

ikram002p · Answer

its anguler speed when its (revolution /minite)
but the qs ask to convert it into linear of the form (inches/minute)=(mile/hour)

ikram002p · Answer

ok ...

yamyam70 · Answer

USing the formula V= R W ?

ikram002p · Answer

now u wanna convert itt from anguler to linear speed , u have the furmula
speed=distance/time

ikram002p · Answer

R is raduis and W is ??

yamyam70 · Answer

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yamyam70 · Answer

that is the combined formula for linear and angular speed

ikram002p · Answer

mmm u can use that , but it well be phisics formula

ikram002p · Answer

but still its the same since on $$revolution (n) = \frac{ w }{ 2\pi }$$

ikram002p · Answer

so use that formula :)
$$w=2\pi n $$ such that n= revolutions

yamyam70 · Answer

2pi rad over 1 rev right :)

ikram002p · Answer

exactly

yamyam70 · Answer

Thanks a lot :) sorry to bother you I'm really f*ck*d up today, today only :)

ikram002p · Answer

so wat is u'll finall answer 
v=?

yamyam70 · Answer

628 mph

ikram002p · Answer

inches =? mile ??

yamyam70 · Answer

ohh forgot that

yamyam70 · Answer

okay, quite lost here.