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3 years ago

6

A ball is thrown from an initial height of 2 meters with an initial upward velocity of 20 m/s. The ball's height h (in meters) a

fter t seconds is given by h=2+20t-5t^2. find all values of t for which the ball's height is 12 meters. Round your answers to the nearest tenth of a second.

1 answer:

Nezavi [6.7K]3 years ago

8 0

2+20t-5t^2=12

5t^2-20t+10=0

t^2-4t+2=0 complete the square

t^2-4t=-2

t^2-4t+4=2

(t-2)^2=2

t-2=± $\sqrt{2}$

t=2± $\sqrt{2}$

t≈(0.586, 3.41)

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3 years ago

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$f(t)=\begin{cases}2-t&\text{for }0\le t$

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$f(t)\sim\dfrac{a_0}2+\displaystyle\sum_{n\ge1}a_n\cos\frac{n\pi t}L$

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$a_n=\displaystyle\frac2L\int_0^Lf(t)\cos\frac{n\pi t}L\,\mathrm dt$

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while for odd $n$ , you have

$a_{n=2k-1}=\dfrac{2-2(-1)^{2k-1}}{(2k-1)^2\pi^2}=\dfrac4{(2k-1)^2\pi^2}$

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4 years ago

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Required

Determine the selling price of 6 goldfish and 4 hermit crabs

The equations are:

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Make g the subject in (2)

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$4g = 28 - 5h$

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Substitute $\frac{1}{4}(28 - 5h)$ for g in (1)

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3 years ago

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