Question

Algebra help please?

Answer 1

Answer is 3 seconds

When the bullet reaches the ground, ground being x in graph (and here its s which is  = 0)

s = -16t^2 + 48t

s = 0, solve for t

0 = -16t^2 + 48t

0 = t ( -16t + 48)

0 = 16t ( - t + 3)

now you have two equation

0 = 16t and 0 = -t +3 ( you can look at the graph line touches x twice)

0 = 16 t

0 = t ( you know its false, because time = 0)

You are left with

0 = -t + 3

t = 3

It takes 3 seconds for the bullet to return to the ground.

// Hope this helps.