Question

If the volume of a sphere is 972(3.14) cubic inches what is the radius- a. 7 icnches b. 9 inches c. 108 inch d. 324 inch

Answer 1

The volume of a sphere is $V=\frac{4}{3}\pi r^3$. Our volume is given to us as $972\pi$, so we fit that into the equation to solve for the radius. It looks like this when we do that. It doesn't matter that we use the pi symbol instead of the 3.14 value, because they cancel each other out anyway. Watch. $972\pi =\frac{4}{3}\pi r^3$. First thing we will do is multiply both sides by 3 to get rid of the fraction. $2916\pi =4\pi r^3$. Now we divide both sides by 4pi. The pi's will cancel each other out, leaving us with $729=r^3$. Now we take the cubed root of 729 on our calculators to get that r = 9. Choice b.

Answer 2

Hi!

To find the volume of a sphere you have to solve an equation, pretty easy once you get the hang of it!

The equation you will need is, V = $\frac{4}{3}$$\pi$r³

The first part is 4/3 multiplied by $\pi$ by the radius (half the diameter) 

So since we do not have the radius, we have to insert the volume in the V variable and solve from there, 

972 
so that divided by 4/3 (3.14) should get you your answer, which is 9
Hope I helped