Answer: To find out how long after the rocket is launched will it be 10 feet from the ground, we need to solve for t in the equation:
h = -16t^2 + 150t + 40
We know that when the rocket is 10 feet from the ground, h = 10:
10 = -16t^2 + 150t + 40
Subtracting 10 from both sides:
0 = -16t^2 + 150t + 30
Dividing both sides by -2:
0 = 8t^2 - 75t - 15
Using the quadratic formula:
t = (-b ± sqrt(b^2 - 4ac)) / 2a
where a = 8, b = -75, and c = -15.
Plugging in these values:
t = (-(-75) ± sqrt((-75)^2 - 4(8)(-15))) / 2(8)
Simplifying:
t = (75 ± sqrt(5715)) / 16
Therefore, the rocket will be 10 feet from the ground approximately 0.26 seconds and 8.05 seconds after it is launched.
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Explanation: