SOLUTION: An astronaut on the moon tosses a ball upwards; when will the ball initially be 35 feet above the lunar surface if the ball's height (feet) follows: h(t)=-2.6t^2+32.1t_5.5, and t i

Algebra ->  Equations -> SOLUTION: An astronaut on the moon tosses a ball upwards; when will the ball initially be 35 feet above the lunar surface if the ball's height (feet) follows: h(t)=-2.6t^2+32.1t_5.5, and t i      Log On


   

Question 146307: An astronaut on the moon tosses a ball upwards; when will the ball initially be 35 feet above the lunar surface if the ball's height (feet) follows: h(t)=-2.6t^2+32.1t_5.5, and t is in seconds from release?
a)1 second
b)2 seconds
c)1/2 seconds
d)13.2 seconds
I came up with 1 second and 11.. a little confused.
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
An astronaut on the moon tosses a ball upwards; when will the ball initially be 35 feet above the lunar surface if the ball's height (feet) follows:
h(t)=-2.6t^2+32.1t_5.5, and t is in seconds from release?
a)1 second
b)2 seconds
c)1/2 seconds
d)13.2 seconds
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-2.6t^2 + 32.1t + 5.5 = 35
-2.6t^2 + 32.1t -29.5 = 0
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The 1st time the ball reaches 35 ft. (on the way up) is 1 second.
The 2nd time it reaches 35 ft. (on the way down) is 11.35 seconds
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Cheers,
Stan H.