Please Help with this calc question

Question

 

1)     An accident at an oil drilling platform is causing a circular oil slick.  The slick is 0.08 foot thick, and when the radius is 750 feet, the radius of the slick if increasing at the rate of 0.5 foot per minute.  At what rate (in cubic feet per minute) is oil flowing from the site of the accident?

Answer 1

 

Area of a Cylinder:		pirrh		F(x)
		dr/dt*2r*h+pirr*dh/dt		F'(x)
	u	v		r/(dr/dt)=	h/(dh/dt)
	pirr	h		750/.5	=	.08/(dh/dt)
	dr/dt*2r	dh/dt		1500	=	.08/(dh/dt)
dr/dt*2r*h+pirr*dh/dt				5.33333E-05	=	(dh/dt)
r	dr/dt	h	dh/dt
750	0.5	0.08	5.33333E-05
dr/dt*2r*h+pirr*dh/dt
=.5*2*750*.08+pi()*750*750*5.33333E-5
154.2477207	cubic feet a minute