Question 1009578
the equation is -16t^2+150t+50, the middle term being the upward velocity and the last term being the height it started at.
The vertex is at -150/-32=4.6875, and the height is 401.56 feet
Setting the equation equal to zero,
-16t^2+150t+50=0 or 16t^2-150t-50=0
t=(1/32) { 150 +/- sqrt (22500+3200)}, where sqrt (25700)=160.31
t=(1/32)310.31=9.697 sec or 9.7 seconds TIME TO LANDING

===============
0---50
1--184
2--286
3--356
4--394
5--400
6--374
7--316
8--226
9--104
10--has hit 
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axis of symmetry is at vertex or t=4.6875
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negative values would imply the rocket was rising up through the building.
{{{graph(300,200,-10,10,50,500,-16x^2+150x+50)}}}