Question 173463
The volume of the cylinder  with water level at 20 cm is {{{V=(pi)(10)^2(20)}}}
:
{{{2000(pi)}}}cu cm
:
volume of the sphere is {{{V=(4/3)(pi)(10)^2}}}
:
{{{133.33(pi)}}}
:
the water level has to rise to account for the displaced volume water when the  sphere is placed in it and has to be equal to the volume of the sphere.
:
so we will add the volume of the sphere to the volume of the cylinder and solve for the unknown h.
:
{{{2000(pi)+133.33(pi)=2133.33(pi)}}}
:
{{{2133.33(pi)=(pi)(10)^2h}}}
:
{{{2133.33=100h}}}
:
{{{highlight(h=21.33)}}}cm is the level of the water after the sphere is place in it.