3. A ball is thrown straight up with an initial velocity of 128 fi/sec., so that its height (in feet) after f seconds is given by s(1) = -16r# +1287 A. What is the average velocity of the ball over the time intervals? a. [2,3] b. [2. 2.5] c. [2. 2.1] B. What is the instantaneous velocity at time r = ?? C. What is the instantaneous velocing at time f-5? Is the ball rising or falling? D. When will the ball hit the ground? 4. An object is dropped from a certain height. It is known that it will fall a distance s, in feet, in / seconds, given by s(1)-1671 A. How far will it fall in 3 sec? B. How far will it fall in 5 sec? C. What is the average rate of change of distance with respect to time during the period from 3 to 5 sec? (This is also average velocity). 5. During the construction of a high-rise building, a worker accidentally dropped his portable electric screwdriver from a height of 400 fl. After / seconds, the screwdriver had fallen a distance of s(1) =-1612 +400 A. How long did it take the screwdriver to hit the ground? B. What was the average velocity of the screwdriver between the times it was dropped and the time it hit the ground? C. What was the velocity of the screwdriver at the time it hit the ground? 6. The initial population in a bacteria colony is 10,000. After t hours, the colony has grown to a number P(t) given by P(!) = 10,000(1+086 +7) A. Find the rate of change of the population P with respect to time. This is also known as growth rate. B. Find the number of bacteria present after 5 hours. C. Find the growth rate when / = 5. 7. A company determines that the monthly sales S, in thousands of dollars, after t months of marketing a product is given by S(1) - 2-40r +220r +160 (Hint: graph the fiction, viewing window: x min 0, max 17, scale 2; y min150, max 600, scale 25) A. Find the monthly sales after 1 month; 4 months; 6 months; 9 months and 20 months B. Find the rate of change S'(t). C. Find the rate of change at t = 1; t= 4; t = 6; t= 9; t = 20