If an object is dropped from a height of 144 ft, the function h(t) = –16t² + 144 gives the height of the object after t seconds. When will the object hit the ground?
(1 point)
A) 1.5 s
B) 3 s
C) 6 s
D) 9 s
To find when the object will hit the ground, we need to set h(t) = 0 and solve for t.
-16t² + 144 = 0
Divide both sides by -16:
t² - 9 = 0
Factor the equation:
(t - 3)(t + 3) = 0
Set each factor equal to zero and solve for t:
t - 3 = 0 --> t = 3
t + 3 = 0 --> t = -3
Since time cannot be negative in this context, the object will hit the ground at t = 3 seconds.
The answer is B) 3 s.