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3 years ago

7

You are on your balcony and notice some bad squirrels digging in your garden directly below. You start tossing your pistachios a

t them to get them out of your yard. If the height of your guard rail is 43 inches above the deck, which is at a standard height of 10 feet above the ground, and you toss the pistachios straight down with a speed of 7.4 m/s, then how long does it take for the pistachio to reach the ground?

1 answer:

Rashid [163]3 years ago

3 0

Answer:

0.43 s

Explanation:

We have the following parameters:

Initial velocity, u = 7.4 m/s

Acceleration of gravity, g = 9.8 $m/s^2$

Distance, s = 43 in + 10 ft = 1.092 m + 3.048 m = 4.14 m

Time, t = ?

Using the equation of motion $s=ut +\frac{1}{2}gt^2$ , we have

$4.14 = 7.4t + 0.5\times9.8t^2$

$4.9t^2 + 7.4t - 4.14 =0$

Using the quadratic formula $\dfrac{-b\pm\sqrt{b^2-4ac}}{2a}$ where a = 4.9, b = 7.4 and c = - 4.14, and solving for the positive value of t only, we have

$t = 0.43$ s

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$\frac{k(1.90.10^{-6})(3.03.10^{-6})}{x^{2}}=\frac{k(2.84.10^{-6})(3.03.10^{-6})}{(x-0.301)^{2}}$

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