Question 1143733
One piece of ash was ejected from a volcano with a initial velocity of 336ft/sec. The heigh H in feet is given by the equation H=-16t^2+336t where T is the time in seconds.
When does the ash projectile reach its maximim height?
It's the vertex of the parabola at t = -b/2a
Solve for t
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What is its maximum height?
Sub t at the vertex.
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when does the ash projectile return to the ground? 
When -16t^2 + 336t = 0
Which is 2 times the t at the vertex.