SOLUTION: Hi, would you help me solve this problem, please? A person standing close to the edge on the top of a 311-foot building throws a baseball vertically upward. The quadratic equatio

Algebra ->  Customizable Word Problem Solvers  -> Misc -> SOLUTION: Hi, would you help me solve this problem, please? A person standing close to the edge on the top of a 311-foot building throws a baseball vertically upward. The quadratic equatio      Log On

Ad: Over 600 Algebra Word Problems at edhelper.com


    

Question 903519: Hi, would you help me solve this problem, please?
A person standing close to the edge on the top of a 311-foot building throws a baseball vertically upward. The quadratic equation:
+h=-16t%5E2+%2B+128t+%2B+311 models the ball's height "h" above the ground in feet, "t" seconds after it was thrown.
1a)How high is the ball after 4 seconds?
I got 567 feet but this might be incorrect.
1b) How many seconds does it take until the ball finally hits the ground? Round to nearest tenth of a second.
Thank you!
Answer by richwmiller(17219) About Me  (Show Source):
You can put this solution on YOUR website!
a) h=-16t^2 + 128t + 311
plug in 4 for t
567 is correct
b)
h=-16t^2 + 128t + 311
plug in 0 for h
t=9.95294 seconds