Question

WILL GIVE BRAINIEST A ball is thrown from a height of 45 meters with an initial downward velocity of 5/ms. The ball's height h (in meters) after t seconds is given by the following. =h−45−5t5t2 How long after the ball is thrown does it hit the ground?

Answer 1

Answer:

2.16 s

Step-by-step explanation:

When it hits the ground, height h=0 hence

0=45-10t-5t^{2}

5t^{2}+10t-45=0

t^{2}+2t-9=0

Using quadratic formula

x=-1+\sqrt 10\\ x=-1-\sqrt 10

Since time can't be negative, -1+\sqrt 10

t=2.16 s