SOLUTION: The equation (((h=-16^2-32t+320))), gives the height of a ball, thrown downward from the top of a 320ft building with an initial velocity of 32ft/sec. Find the time it takes for th

Question 30017: The equation (((h=-16^2-32t+320))), gives the height of a ball, thrown downward from the top of a 320ft building with an initial velocity of 32ft/sec. Find the time it takes for the ball to reach a height 160ft. Heres what I have so far, h=160, 160=16t^2+32t+320,160=0,16t^2+32t-320=0,divide by 16,
leaving t^2+2t-20, using the quadratic formula t=b(+or-)radical sign (-2)^2-4(1)(20)/2=0, 2(+or-)radical sign 4+80/2, so the answer I get is 2+ radical sign,84/2, and 2- radical sign 84/2. My math book says the answer is 2.317seconds, but does not show how to get there. Thanks,

Answer by Cintchr(481) (Show Source): You can put this solution on YOUR website!
this is a repeat of Question 30017 from Travel_Word_Problems
RELATED QUESTIONS
The equation h=-16t^2-32t+320 gives the height od a ball, thrown downward from the top of (answered by Nate)

The equation h=-16t^2-32t+320 Give the height of a ball, thrown donward from top of a... (answered by checkley71)

The equation (((h=-16^2-32t+320))), gives the height of a ball, thrown downward from the... (answered by Cintchr)

h=-16t^2-32t+320 gives the height of a ball thrown downward from the top of a 320 foot... (answered by Alan3354)

I need to understand each step in the procedure to show and explain EACH step in setting... (answered by Nate)

I am really having troubles with these word problems. the equation -16t^2 - 32t +... (answered by josmiceli)

A building is 48 ft. tall. From the top of this building a ball is thrown straight up... (answered by funmath)

Elena throws a ball into the air from a building. The equation h= -16t^2 +32t+48 gives... (answered by Alan3354)

A ball is thrown downward from the top of a 180 foot building with an initial velocity of (answered by richwmiller)