A bicycle wheel makes 5000 revolution is moving 11k.m. the diameter of the wheel is ?

Question

anonymous · Answer

hey

mathmale · Answer

Hint:  the formula for "arc length" is $$s=r* \theta$$  where s=arc length, theta=the central angle (this MUST be expressed in radians), and r=the radius (not diameter) of the circle.

aravindg · Answer

5000 revolutions=1 km
1 revolution=?

Remember that during 1 revolution the cycle wheel travels a distance equal to its circumference.

aravindg · Answer

*11 km

mathmale · Answer

I'm assuming you mean, "A bicycle wheel makes 5000 revolutions AS THE BICYCLE TRAVELS  11 km."  Does that sound reasonable to you?

If so, taking AravindG's suggestion, divide the distance traveled by the circumference of the bike wheel.  Since we do not yet know the wheel diameter or radius, just use ' r ' for the unknown radius.  Our goal is to find the radius, and then from it, the diameter of the bike wheel.  What would you do next?

What is the formula for the circumference of a circle of radius r?
What is the formula for the circumference of a circle of diameter d?

goformit100 · Answer

C = 2 pi r

mathmale · Answer

Got it!  So, what's your next step?  And what significance will the result of taking that step have?

mathmale · Answer

Caution:  Be careful with your units of measurement here!

goformit100 · Answer

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What to do next ?