A bicycle has tires of radius 0.35 meters. If the bicycle is traveling at a constant speed of 7.8 m/s, at approximately what angular speed are the tires rotating?

Question

A bicycle has tires of radius 0.35 meters.  If the bicycle is traveling at a constant speed of 7.8 m/s, at approximately what angular speed are the tires rotating?

anonymous · Answer

Circumference of tire?

anonymous · Answer

2Pi r , right?

anonymous · Answer

yah.

anonymous · Answer

first I use formual V= r omega to find omega. then I conver rad/s to rev/ min. But i did not get right answer :(

anonymous · Answer

$$ \left( \frac{7.8m}{s} \right) \left( \frac{2 \pi rad}{2 \pi r}\right)  = \frac{7.8}{r}rad/s$$

Why did you convert to rev/min?

anonymous · Answer

that sounds like you did it right

anonymous · Answer

does the answer have to be in rev/min?

anonymous · Answer

yes

anonymous · Answer

I donet get why you use (2pi rad/ 2pi r)

anonymous · Answer

That's basically the formula you used; I was just doing a conversion.  2 pi radians per circumference.  It's the V = r omega

anonymous · Answer

the answer is 214

anonymous · Answer

I get 213...

anonymous · Answer

if you do like that you will have omega = 22.2 rad/ s

anonymous · Answer

$$ \frac{7.8m/s}{.35m} \cdot \frac{ 1 \ rev}{2 \pi rad} \cdot \frac{60 s}{1 \ min} = 213 $$

anonymous · Answer

that is the way i did , but i did not get right answer. I still dont understand

anonymous · Answer

ok I got it

anonymous · Answer

still dunno why it's 1 off tho... :P

anonymous · Answer

no i got it now

anonymous · Answer

nice ^_^

anonymous · Answer

thanks I have some more question.

anonymous · Answer

go for it ^^

anonymous · Answer

a bicycle travels 141 m along a circular track of radius 15 m what is the angular displacement in radians of the bicycle from its strating postion ?

anonymous · Answer

and a grindstone, initially a rest is given a constant angular acceleration so that is makes 20 rev in the first 8s what is angualar acceleration? (ans : 3.93 rad/S^2)

anonymous · Answer

What's your try for the bike?  Your intuition has been spot on for everything so far :)

anonymous · Answer

:) bc bicycle is harder to ride than the car haaaaa

anonymous · Answer

if you dont know it, we can skip it

anonymous · Answer

^_^  lol  

I know it, just thought you might have a go.

Circular motion is all pretty much conversion questions.  What do you get when you divide the distance traveled by the bike by the circumference of the track?

anonymous · Answer

the radius right

anonymous · Answer

?? nope.  Try again.

anonymous · Answer

omg i have not idea

anonymous · Answer

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You get the number of revolutions the bike has completed