1. The height H of a ball thrown vertically upward is given by H = -16t2 + 64t + 44, where the time t is in seconds and the height H is in feet.
a. How long does it take for the ball to hit the ground? (Round your answer to two decimal places.)
b. What is that maximum height?
2. Joe wants to toss a ball up to his friend Kate who is standing on the roof of a 75 foot high building. He tosses the ball upward with an initial velocity of 40 feet per second and releases it at a height of 4 feet above the ground.
a. If the ball does not reach roof level, experiment with the value for the initial velocity to find the minimal initial velocity where the ball will rise to that level. (Round your answer to the nearest whole number. If an answer does not exist, enter DNE.)
3. t is the number of years since 1995 r=-0.000137t^4-0.008364t^3+0.189606t^2-0.966496t+5.865740
a. Use the function to predict the unemployment rate (as a %) in 1994. (Round your answer to one decimal place.)