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Quadratic equation The height of a rocket in metres can be found by the function    ...

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paulbarton | Honors

Posted October 29, 2012 at 10:17 PM via web

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Quadratic equation

The height of a rocket in metres can be found by the function                     h(t) = -4.9t^2+ 540t + 25, where t is the time in seconds. When is the height of the rocket 0 metres?

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jeew-m | College Teacher | (Level 1) Educator Emeritus

Posted October 30, 2012 at 5:03 AM (Answer #1)

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`h(t) = -4.9t^2+ 540t + 25`

When the height is 0;

`-4.9t^2+ 540t + 25 = 0`

The solution for above quadratic equation is given by;

`t = ((-540)+-sqrt(540^2-4*(-4.9)*25))/(2*(-4.9))`

 

`t = -0.0463` OR `t = 110.25`

Usually time is a positive component. So t = -0.0463 not acceptable.

So the rocket height is 0 when the time is 110.25 seconds.

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