Question 247743
 A cannonball is fired form ground level on an arc described by h = -t^2 + 28t where "h" is the height in meters at any time "t" in seconds. Determine the number of seconds it would take the ball to reach a height of 192m. At what other point in its flight is also at 192m?
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h(t) = -t^2 + 28t = 192
t^2 - 28t + 192 = 0
*[invoke solve_quadratic_equation 1,-28,192]
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It takes 12 seconds to reach 192 meters.
It's again at 192 meters on its way down at 16 seconds.
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The max height will be at 14 seconds, and the max is 196 meters.
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This must be on a small planet or asteroid to have a gravity of 2 m/sec/sec.
On Earth, it's 9.8 m/sec/sec, and the equation is -4.9t^2 for the acceleration term.