math help. Algebra word problem?
A model rocket is launched with an initial upward velocity of 215ft/s . The rocket's height h (in feet) after t seconds is given by the following.
h=215t-16t^(2)
Find all values of t for which the rocket's height is 97 feet.
Round your answers to the nearest hundredth.
Please answer and explain. thanks for the help.
Comments
97 = 215t - 16t^2
16t^2 - 215t + 97 = 0
a = 16
b = -215
c = 97
[-b ± √(b^2 - 4ac)] / 2a
(215 ± √40017) / 32
t = 12.970077983916697359451253891375
t = 0.46742201608330264054874610862542
12.97 seconds
.47 seconds