6. A fuel truck, has a cylindrical tank of radius R = 2 m and length L = 10 m lying horizontally. The volume of gasoline in the tank is given by R - h V =L R' cos- 1 R - (R - h)v2Rh - hz where h is the vertical height of the gasoline in the tank. If gasoline is being pumped into the tank at a rate of 2 mo/min, how fast is the gasoline level rising when the height h of the gasoline is 1 m