(ii) t = 4.2 9. The volume of a cylinder with radius r and height h is given by V = It r h. The radius and height of the cylinder are increasing at constant rates. The radius is expanding at 1cm/3 sec and the height is increasing at 1cm/2 sec. At what rate, in cubic cm per second, is the volume of the cylinder increasing when its height is 9 cm and the radius is 4 cm? (6 points possible) 10. An airplane flies at an altitude of 5 miles toward a point directly over an observer. The speed of the plane is 600 mile per hour. Find the rates at which the angle of elevation 0 is changing when the angle is (a) 0 = 30, (b) 0 = 60, and (c) 0 = 70. (10 points possible) DO 5 mi Not drawn to scale