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3 years ago

13

Scientists believe that our solar system formed about 4.6 billion years ago from a cloud of hydrogen, helium, rock, ice, dust, a

nd other material.
True
False

2 answers:

Pachacha [2.7K]3 years ago

8 0

Answer:

Scientists believed it. It is hypothesis because it is not yet proved.

Explanation:

Elena-2011 [213]3 years ago

4 0

False
I took that answer and I thought it was true it wasn’t

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Radioactive wastes are temporarily stored in a spherical container, the center of which is buried a distance of 10 m below the e

a_sh-v [17]

Answer:

Outside temperature =88.03°C

Explanation:

Conductivity of air-soil from standard table

K=0.60 W/m-k

To find temperature we need to balance energy

Heat generation=Heat dissipation

Now find the value

We know that for sphere

$q=\dfrac{2\pi DK}{1-\dfrac{D}{4H}}(T_1-T_2)$

Given that q=500 W

so

$500=\dfrac{2\pi 2\times .6}{1-\dfrac{2}{4\times 10}}(T_1-25)$

By solving that equation we get

$T_2$ =88.03°C

So outside temperature =88.03°C

6 0

4 years ago

g A steel water pipe has an inner diameter of 12 in. and a wall thickness of 0.25 in. Determine the longitudinal and hoop stress

zvonat [6]

Answer:

a) $\mathbf{\sigma _ 1 = 4800 psi}$

$\mathbf{ \sigma _2 = 0}$

b) $\mathbf{\sigma _ 1 = 6000 psi}$

$\mathbf{ \sigma _2 = 3000 psi}$

Explanation:

Given that:

diameter d = 12 in

thickness t = 0.25 in

the radius = d/2 = 12 / 2 = 6 in

r/t = 6/0.25 = 24

24 > 10

Using the thin wall cylinder formula;

The valve A is opened and the flowing water has a pressure P of 200 psi.

So;

$\sigma_{hoop} = \sigma _ 1 = \frac{Pd}{2t}$

$\sigma_{long} = \sigma _2 = 0$

$\sigma _ 1 = \frac{Pd}{2t} \\ \\ \sigma _ 1 = \frac{200(12)}{2(0.25)}$

$\mathbf{\sigma _ 1 = 4800 psi}$

b)The valve A is closed and the water pressure P is 250 psi.

where P = 250 psi

$\sigma_{hoop} = \sigma _ 1 = \frac{Pd}{2t}$

$\sigma_{long} = \sigma _2 = \frac{Pd}{4t}$

$\sigma _ 1 = \frac{Pd}{2t} \\ \\ \sigma _ 1 = \frac{250*(12)}{2(0.25)}$

$\mathbf{\sigma _ 1 = 6000 psi}$

$\sigma _2 = \frac{Pd}{4t} \\ \\ \sigma _2 = \frac{250(12)}{4(0.25)}$

$\mathbf{ \sigma _2 = 3000 psi}$

The free flow body diagram showing the state of stress on a volume element located on the wall at point B is attached in the diagram below

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4 years ago

Two vehicles arrive at an uncontrolled intersection from different streets at the same time 1.The driver on the right must yield

ss7ja [257]

3. Both vehicles must stop

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3 years ago

36. What is mass? (4.4)

KatRina [158]

Answer:

Mass, in physics, quantitative measure of inertia, a fundamental property of all matter.

Explanation:

Mass is the matter that makes up objects

3 0

3 years ago

Find the total amount of heat in Q lost through a wall 10' by 18' , with R value from q. 1. Inside temperature is 70 degrees F w

marissa [1.9K]

Answer:

Just think

Explanation:

6 0

4 years ago

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