Question

A ball is thrown into the air with an initial upward velocity of 45 ft/s. The height (h) in feet is given by the equation below. After about how many seconds will the ball hit the ground?

Answer 1

h=-16t^2+45t+6

Answer 2

t represent time
h = height
what would be the height when ball hit the ground ?

Answer 3

height = ?

Answer 4

t?

Answer 5

t = time we need to find time
but when ball hits the ground h =0
so replace h by 0 \[\huge\rm 0=-16t^2+45t+6\] and now solve for t
you can use quadratic formula \[ \huge\rm \frac{ -b \pm \sqrt{b^2 - 4ac} }{ 2a }\]

Answer 6

a b c
Ax^2 +Bx +C = 0