For $7-10,$ set up and evaluate the integral that gives the volume of the solid formed when the region bound by the given lines is revolved about the $y-$axis.

$7.y=3x^2,x=0,y=5$

$8.y=sin(x^2),y=\frac{1}{2},x=0$

$9.y=\frac{1}{x},y=1,y=4,x=0$

$10.9x^2+25y^2=225,x=0,y=0$