word problem

Question

 
 
A toy ball (sphere) expands and contracts. When it is completely closed, it has a diameter of 15.5
inches. Find the volume of the sphere when it is completely closed. Use 3.14 for piπ.
Round to the nearest whole cubic inch.  
(Hint: volume of a sphere equals four thirds pi r cubed .=43πr3.

Answer 1

V = (4/3)πr³

 

If the diameter is 15.5 inches, then the radius is 1/2 * 15.5 = 7.75 in.

 

V = (4/3)(3.14)(7.75)³

 

V = 1949 in³