Question

Molly wishes to make a lawn ornament in the form of a solid sphere. The clay being used to make the sphere weight 0.075 pound per cubic inch. If the sphere radius is 4 inches, what is the weight of the sphere, to the nearest pound? A)20 B)15 C)4 D)34

Answer 1

The first thing to do in this case is to find the volume of the sphere.
 We have then:
 V = (4/3) * (pi) * (r ^ 3)
 V = (4/3) * (pi) * ((4) ^ 3)
 v = 268 in ^ 3
 Then, the but of the sphere will be given by:
 W = (0.075) * (268)
 W = 20
 Answer: 
 the weight of the sphere, to the nearest pound is: 
 A) 20