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need help

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The equation y = -16t^2 + 26t + 105 describes the height (in feet) of a ball tossed up in the air at 26 feet per second from a height of 105 feet above the ground. In how many seconds will the ball reach 110 feet? Express your answer as a decimal rounded to the nearest tenth.

Feb 11, 2022

#1
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y = 110

110 = -16t^2 + 26t + 105

0 = -16t^2 + 26t -5                     Now use Quadratic Formula to calcualte 't' values,,,

the smaller t will be on the way up...the larger will be on the way down

a = -16  b = 26  c = -5

$$t = {-26 \pm \sqrt{26^2-4(-16)(-5)} \over 2(-16)}$$

Feb 11, 2022