Question 173465
{{{V=(pi)r^2h}}} volume of a cylinder
:
{{{V=4/3(pi)r^3}}} volume of a sphere
:
let V(C) be the volme of the tennis can and V(S) be the volume of a tennis ball
:
height of sphere is 3(7)=21....diameter of each ball is 7cm
:
{{{V(C)=(pi)(3.5)^2(21)}}}---->{{{v(C)=(pi)(12.25)(21)}}}
:
{{{V(C)=(pi)257.25}}}cu cm
:
{{{V(S)=(4/3)(pi)(3.5)^3}}}---->{{{V(S)=(4/3)(pi)42.875}}}
:
{{{V(S)=57.6(pi)}}} 
:
we must multiply the V(S) by 3 since there are 3 balls
:
{{{57.6(pi)(3)=172.8(pi)}}}
The volume of the air will be V(C)-3V(S)
:
Volume of air{{{257.25(pi)-172.8(pi)=highlight(84.45)(pi)}}}cu centimeters