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3 years ago

___________ are over 500 million years old and have been developing their unique system all that time.

Physics

2 answers:

Varvara68 [4.7K]3 years ago

5 0

Answer:

none the earth isn't that old

Explanation:

zhannawk [14.2K]3 years ago

3 0

Answer:

Explanation:

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Water moves through a constricted pipe in steady, ideal flow. At the

Irina-Kira [14]

A) Speed in the lower section: 0.638 m/s

B) Speed in the higher section: 2.55 m/s

C) Volume flow rate: $1.8\cdot 10^{-3} m^3/s$

Explanation:

To solve the problem, we can use Bernoulli's equation, which states that

$p_1 + \rho g h_1 + \frac{1}{2}\rho v_1^2 = p_2 + \rho g h_2 + \frac{1}{2}\rho v_2^2$

where

$p_1=1.75\cdot 10^4 Pa$ is the pressure in the lower section of the tube

$h_1 = 0$ is the heigth of the lower section

$\rho=1000 kg/m^3$ is the density of water

$g=9.8 m/s^2$ is the acceleration of gravity

$v_1$ is the speed of the water in the lower pipe

$p_2$ is the pressure in the higher section

$h_2 = 0.250 m$ is the height in the higher pipe

$v_2$ is hte speed in the higher section

We can re-write the equation as

$v_1^2-v_2^2=\frac{2(p_2-p_1)+\rho g h_2}{\rho}$ (1)

Also we can use the continuity equation, which state that the volume flow rate is constant:

$A_1 v_1 = A_2 v_2$

where

$A_1 = \pi r_1^2$ is the cross-section of the lower pipe, with

$r_1 = 3.00 cm =0.03 m$ is the radius of the lower pipe (half the diameter)

$A_2 = \pi r_2^2$ is the cross-section of the higher pipe, with

$r_2 = 1.50 cm = 0.015 m$ (radius of the higher pipe)

So we get

$r_1^2 v_1 = r_2^2 v_2$

And so

$v_2 = \frac{r_1^2}{r_2^2}v_1$ (2)

Substituting into (1), we find the speed in the lower section:

$v_1^2-(\frac{r_1^2}{r_2^2})^2v_1^2=\frac{2(p_2-p_1)+\rho g h_2}{\rho}\\v_1=\sqrt{\frac{2(p_2-p_1+\rho g h_2)}{\rho(1-\frac{r_1^4}{r_2^4})}}=0.638 m/s$

Now we can use equation (2) to find the speed in the lower section:

$v_2 = \frac{r_1^2}{r_2^2}v_1$

Substituting

v1 = 0.775 m/s

And the values of the radii, we find:

$v_2=\frac{0.03^2}{0.015^2}(0.638)=2.55 m/s$

The volume flow rate of the water passing through the pipe is given by

$V=Av$

where

A is the cross-sectional area

v is the speed of the water

We can take any point along the pipe since the volume flow rate is constant, so

$r_1=0.03 cm$

$v_1=0.638 m/s$

Therefore, the volume flow rate is

$V=\pi r_1^2 v_1 = \pi (0.03)^2 (0.638)=1.8\cdot 10^{-3} m^3/s$

Learn more about pressure in a liquid:

brainly.com/question/9805263

#LearnwithBrainly

0 0

3 years ago

You place your pencil on your desk it stays there

zepelin [54]

Answer:

yes

Explanation:

6 0

3 years ago

Read 2 more answers

A 74 kg firefighter slides, from rest, 4.9 m down a vertical pole. (a) If the firefighter holds onto the pole lightly, so that t

In-s [12.5K]

Answer:

Her speed is 9.8 meter per second

Explanation:

Newton's second law states that acceleration (a) is related with force (F) by:

$\sum\overrightarrow{F}=m\overrightarrow{a}$ (1)

Here the only force acting on the firefighter is the weight F=mg so (1) is:

$mg=ma$

Solving for a:

$a=g$

Now with the acceleration we can use the Galileo's kinematic equation:

$Vf^{2}=Vo^{2}+2a\varDelta x$ (2)

With Vf the final velocity, Vo the initial velocity and Δx the displacement, because the firefighter stars from rest Vo=0 so (2) is:

$Vf^{2}=2a\varDelta x$

Solving for Vf

$Vf=\sqrt{2g\varDelta x}=\sqrt{2(9.81)(4.9)}$

$Vf=9.8\frac{m}{s}$

6 0

3 years ago

Studies of sedimentary rocks and fossils have helped scientists understand the history of Earth. How is geologic time organized

grin007 [14]

Eras and then smaller periods based on geologic and biologic events that occurred during those times. According to geological time scale, there are six eras from the beginning some periods of few eras & then period is classified into smaller units called "epoch"

In short, Your Answer would be Option B

Hope this helps!

7 0

3 years ago

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2. Explain brightness of light using the wave model of light.

Dafna11 [192]

The amplitude of a wave tells us about the intensity or brightness of the light relative to other light waves of the same wavelength.

5 0

2 years ago

Read 2 more answers