1AM) 0.0f2.0 points {graded} What is the following limit? 7/4_ L=Hm$1 mil $1 Hint: solve by writing it as a derivative. L: 1A (1) 3 points possible (graded) A test tube is knocked off a tower at the top of a building that is 400 feet above the ground. [For our purposes. we will assume that air resistance is negligible.) The test tube drops 'I6t2 feet in t seconds. (a): Calculate the average velocity in the first two seconds of the fall. (Enter answer as a decimal number. Use the convention that velocities downward are negative.) feet per second (b) Calculate the average velocity in the last two seconds of the fall. (Enter answer as a decimal number. Use the convention that velocities downward are negative.) feet per second (c) Calculate the instantaneous velocity when the test tube lands. feet per second