PROBLEM 12-92 (page 48, 12th edition Water is discharged from the hose with a speed of 40 ft/s. · Determine the two possible angles 0 the firefighter can hold the hose so that the water strikes the building at B. Take s = 20 ft. VA = 40 ft/s B A 10 8 ft 4 ft S PROB12_091-092.jpg Copyright 2010 Pearson Prentice Hall, Inc.
12-92 (page 48, 12th edition) COMPLETION OF PROBLEM · Trajectory equation y(x) = a(x! x, )2 + b(x! x)+y. g 2 " 0 a = ! 2v, cos- b = tan! 0 · Data V = 40ft/s (Xo, yo)= (0, 4)ft (x, y)= (20, 8)ft : 8 = ! 2(40)2 cos2 "0 32.2(20)2 + 20tan" + 4 Solver ! 0 = 23.8 o ! 0 = 77.5 o
PROBLEM 12-120 (page 66, 14th edition) PROBLEM 12-124 (page 62, 13th edition) PROBLEM 12-120 (page 61, 12th edition) The car travels along the circular path. Starting from rest, its acceleration along the path is 0.5 e' m/s2 where t is in seconds. · Determine how long it takes the car to travel 18 m. · Determine the car's speed and acceleration at this time. s = 18 m p= 30 m PROB12_120.jpg Copyright 2010 Pearson Prentice Hall, Inc.