13. a catapult launches a boulder with an upward velocity of 148 ft/s. the height of the boulder (h) in feet after t seconds is given by the function h = –16t² + 148t + 30. how long does it take the boulder to reach its maximum height? what is the boulder’s maximum height? round to the nearest hundredth, if necessary.
a) 9.25 s; 30 ft
b) 4.63 s; 640.5 ft
c) 4.63 s; 1,056.75 ft
d) 4.63 s; 372.25 ft

16. solve the equation using the zero product property.
(2x – 4)(2x – 1) = 0
a) 2, –1over2
b) 2, 1over2
c) –2, 2
d) –2, 1over2

In an old-fashioned amusement park ride, passengers stand inside a 3.0-m-tall, 5.0-m-diameter hollow steel cylinder with their backs against the wall. the cylinder begins to rotate about a vertical axis. then the floor on which the passengers are standing suddenly drops away! if all goes well, the passengers will “stick” to the wall and not slide. clothing has a static coefficient of friction against steel in the range 0.60 to 1.0 and a kinetic coefficient in the range 0.40 to 0.70. part a what is the minimum rotational frequency, in rpm, for which the ride is safe? express your answer using two significant figures. f f = rpm