1 At a sand gravel plant sand is

#1 At a sand gravel plant, sand is falling off a conveyor and into a conical pile at the rate of 10 ft 3/min. The diameter of the base of the cone is three times the altitude. At what rate is the height of the pile changing when it is 15 ft high? Point Value : 50 time limit : 5 min

#2 A ladder 25 ft long is leaning against the wall of a house. The base of the ladder is pulled away from the house at a rate of 2 ft/sec. Find the rate at which the angle between the top of the ladder and the wall of the house is changing when the base of the ladder is 7 feet from the wall. Point Value : 40 time limit : 4 min

#3 An airplane is flying in still air with an airspeed of 240 mph. If it is climbing at an angle of 220, find the rate at which it is gaining altitude. Point Value : 30 time limit : 4 min

#4 Two sides of a triangle have lengths 12 m and 15 m. The angle between them is increasing at a rate of 2 o/min. How fast is the length of the third side increasing when the angle between the fixed lengths is 60 o? Point Value : 50 time limit : 5 min

#5 Point Value : 50 time limit : 5 min

#6 A large red balloon is rising at the rate of 20 ft/sec. The balloon is 10 ft above the ground at the point in time that the back end of a green car is directly below the bottom of the balloon. The car is traveling at 40 ft/sec. What is the rate of change of the distance between the bottom of the balloon and the point on the ground directly below the back of the car one second after the back of the car is directly below the balloon? Point Value : 40 time limit : 4 min

#7 Point Value : 30 time limit : 3 min

#8 Point Value : 40 time limit : 4 min

#9 time limit : 5 min Point Value : 50