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

Na food processing facility, a spherical container of inner radius r1 5 40 cm, outer radius r2 5 41 cm, and ther- mal conductivity k 5 1.5 w/m · k is used to store hot water and to keep it at 100°c at all times. to accomplish this, the outer surface of the container is wrapped with a 800-w electric strip heater and then insulated. the temperature of the inner surface of the container is observed to be nearly 120°c at all times. as- suming 10 percent of the heat generated in the heater is lost through the insulation, (a) express the differential equation and the boundary conditions for steady one-dimensional heat conduction through the container, (b) obtain a relation for the variation of temperature in the container material by solving the differential equation, and (c) evaluate the outer surface tempera- ture of the container. also determine how much water at 100°c this tank can supply steadily if the cold water enters at 20°c.

Imagine you are riding on a yacht in the ocean and traveling at 20 mph. you then hit a golf ball at 100 mph from the deck of the yacht. you see the ball move away from you at 100mph, while a person standing on a near by beach would observe your golf ball traveling at 120 mph (20 mph + 100 mph). now imagine you are aboard the hermes spacecraft traveling at 0.1c (1/10 the speed of light) past mars and shine a laser from the front of the ship. you would see the light traveling at c (the speed of light) away from your ship. according to einstein’s special relativity, how fast will a person on mars observe the light to be traveling? a) 0.1c (1/10 the speed of light) b) c (the speed of light) c)1.1c (c+0.1c)

The two required components for a generator are