1. Suppose a particular jet needs to attain a speed of 220 mph to take off. If it can accelerate from 0 to 220 mph in 30 seconds, how long must the runway be? Assume constant acceleration. Note: 1 mph = 22/15 ft/sec.
2. A water balloon launched from the roof of a building at time t = 0 seconds has vertical velocity v(t) = -32t + 40 feet/sec with positive v corresponding to upward motion. s(t) = -16t^2+40t+60. A 6-foot person is standing on the ground. How fast is the water balloon falling when it strikes the person on the top of the head? Give an exact value. Speed =? feet/sec