Question 878045
s = 120t-16t^2
this is an equation for a parabola that opens downward
the time t where it changes direction is -b/2a, therefore
t = -(120) / 2(-16) = 120/32 = 3.75 seconds
the height s is
s = 120(3.75) - 16(3.75)^2 = 435.9375 feet
therefore in 3.75 seconds the fireworks will explode at at height of 436 feet