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3 years ago

Kara drops a rock from the edge of a cliff and it takes 7.00 s for the rock to reach the ground. What is the cliff’s height?

Physics

1 answer:

stepan [7]3 years ago

5 0

Answer:

h = 204.1 m

Explanation:

Given that,

Time taken to reach the ground, t = 7 s

We need to find the height of the cliff. We can find it using second equation of kinematics as follows :

$h=ut+\dfrac{1}{2}at^2$

Here,

u = 0 (at rest initially)

a = g

So,

$h=\dfrac{1}{2}gt^2\\\\h=\dfrac{1}{2}\times 9.8\times 7^2\\\\h=204.1\ m$

So, the cliff's height is 204.1 m.

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The water side of the wall of a 60-m-long dam is a quarter-circle with a radius of 7 m. Determine the hydrostatic force on the d

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Answer:

$26852726.19\ \text{N}$

$57.52^{\circ}$

Explanation:

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Resultant force is

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The direction is given by

$\theta=\tan^{-1}\dfrac{F_y}{F_x}\\\Rightarrow \theta=\tan^{-1}\dfrac{22651982.59}{14420700}\\\Rightarrow \theta=57.52^{\circ}$

The line of action is $57.52^{\circ}$ .

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A 81 kg block is released at a 3.8 m height. the track is frictionless. the block travels down the track, hits a massless spring

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