SOLUTION: help me please A ball is thrown from a height of 45 meters with an initial downward velocity of 5 m/s. The ball's height h (in meters) after t seconds is given by the following.

Question 1173134: help me please
A ball is thrown from a height of 45 meters with an initial downward velocity of 5 m/s. The ball's height h (in meters) after t seconds is given by the following.
h=45-5t-5t^2
How long after the ball is thrown does it hit the ground?
Round your answer(s) to the nearest hundredth.
Answer by ewatrrr(24785) (Show Source): You can put this solution on YOUR website!

 

Hi, 

h=45-5t-5t^2

How long after the ball is thrown does it hit the ground?

h = 0

5t^2 + 5t - 45 = 0

t^2 + t - 9 = 0

 



  Throwing out the negative solution for time

 t = 2.5414s

Wish You the Best in your Studies. 

RELATED QUESTIONS

a ball is thrown from a height of 45 meters with an initial downward velocity of 10 m/s.... (answered by Alan3354)
a ball is thrown from a height of 35 meters with an initial downward velocity of 5 m/s.... (answered by Alan3354)
A ball is thrown from a height of 49 meters with an initial downward velocity of 2 m/s.... (answered by josmiceli)
please help

A ball is thrown from an initial height of 5 feet with an initial upward... (answered by ikleyn)
Could someone help me please? The problem is:
A ball is thrown upward from the roof of a  (answered by Flake,Earlsdon)
A ball is thrown upward from the roof of a building 100 m tall with an initial velocity... (answered by Edwin McCravy)
A ball is thrown from a height of 49 meters with an initial downward velocity of 2 m/s.... (answered by richwmiller)
A ball is thrown upward from the roof of a building 100 m tall with an initial velocity... (answered by Edwin McCravy)
please help me 

A ball is thrown from an initial height of 5 feet with an initial... (answered by ewatrrr,ikleyn)