A project manager placed an order for ball bearings for some heavy duty manufacturing machinery. What is the surface area in square millimeters of one of these bearnings if it has a diameter of 0.7 inches?

Question

anonymous · Answer

Well, you know radius = diameter/2 = .7/2

And surface area  of a sphere is given by: $$A=4*\pi*r^2$$

So, plug in and solve for A.

anonymous · Answer

It needs it in square mm. So how would I do that?

anonymous · Answer

Well, you get the results in inches square, so just convert inches to millimeters

So your diameter is 17.78 mm.