ANSWER: E 16. If a ball is thrown into the air with a velocity of 80 ft/s, its height in feet after t seconds is given by s(t) = 80t – 16t 2. It will be at a maximum height when its instantaneous velocity is zero. Find its average velocity from the time it is thrown (t = 0) to the time it reaches its maximum height.
ANSWER: C 64.A plane flying horizontally at an altitude of 1 km and a speed of 500 km/h passes directly over a radar station. Find the rate at which the distance from the plane to the station is increasing when it is 2 km away from the station.
ANSWER: 12 days 65.A hog weighs 250 pounds. A high-yield diet allows the animal to gain 6 pounds a day at a cost of $0.56 a day. The market price for hogs is currently $0.75 per pound, but is falling at a rate of $0.01 per day, and that price decline is expected to remain steady for the foreseeable future. When should the hog be sold in order to provide the farmer with the highest financial gain?