please help meee

Question

Sam and Sara have taken their Math textbooks to the top of a twelve-story building and look at the pool which is 160 feet straight below them. Sam just lets go of his book, while Sara throws her book down with an initial velocity of 96 feet per second. How many seconds does it take each book to hit the water? Round to the nearest hundredth.

Answer 1

For Sam h(t) = 0 = -16t^2 + 160

t^2 =160/16 = 10

t=sqr10 = about 3.16 seconds to hit the ground

for Sarah h(t) =0 = -16t^2 - 96t + 160, divide by -16 to get

t^2 + 6t -10 = 0 complete the square

t+6t + 9 = 10+9

t+3 = sqr19

t = sqr19-3 = about 4.36-3 = 1.36 seconds to hit the ground