SOLUTION: Im a parent trying to help my daughter...basically the problem is a kid drops a rock from a bridge, h represents height and t represents time in seconds, how long does it take for

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Question 859113: Im a parent trying to help my daughter...basically the problem is a kid drops a rock from a bridge, h represents height and t represents time in seconds, how long does it take for the rock to hit the water from the bridge with the formula h= -16tē-16t+60
Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
According to the equation for h, at t=0, the height, h, is 60. At what time t will h become zero?
You want h=-16t%5E2-16t%2B60=0.

You can use the general solution to a quadratic equation to avoid trying to factorize the quadratic expression; and you need to accept the POSITIVE value for t.

Here is how that is setup but not showing the steps:
t=%2816%2B-+sqrt%2816%5E2-4%28-16%29%2860%29%29%29%2F%282%28-16%29%29
.
highlight%28t=1.5%29 or cross%28t=-2.5%29

You COULD try to factor the quadratic expression - I began to try factoring but doing so brings up a few different trials to check; directly using the general solution is easier.