Radius Question

Question

The volume of a cone of sand moved by harvester ants given it's radius can be found with the following formula  A mound of gravel is in the shape of a cone with the height equal to twice the radius. Calculate the volume of such a mound of gravel whose radius is 3.22 ft. Use .

Answer 1

V=(1/3)pi(r^2)h is the formula for volume of a cone,

where r=radius, h=height and pi= about 3.141593

for r=3.22, pi=3.14 h=r/2 = 1.61

V= (1/3)(3.14)3.22^2(1.61) = about 17.47 ft^3

V=pir^2(r/2)/3

=(1/6)pir^3

=(3.14)3.22^3/6

= 17.47 cubic feet of sand