\
Step 1 :
\Conversion from rectangular to cylindrical co-ordinates :
\
Conversion of integral from rectangular to cylindrical co-ordinates :
\
Step 2 :
\The solid is
.
The density function is
.
Substitute
in above equation. 
The density function in cylindrical co-ordinates is
.
Find the z limits :
\
Substitute
and
in above inequality.

Find the r and
limits :
is an equation of the circle with radius
.
Thus,
and
.
Step 3 :
\Find the mass of the solid :
\The mass is 
Substitute the corresponding values in above equation.
\
Solution :
\The mass of the solid is
.