Draining a half cylinder tank. a trough is shaped like a half cylinder with length 5 m and radius 1 m. the tank is full of water when a valve is opened and water flows out of the bottom of the tank at a rate of 1.5m^3/hr . hint: the area of a sector of a circle of radius r subtended by an angle theta is r^2/2 times theta.
a: how fast is the water level changing when the water level is 0.5 m from the bottom of the trough?