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2 years ago

Explain the significance behind the universe having a flat geometry.

2 answers:

6 0

In a flat universe, Euclidean geometry applies at the very largest scales. This means parallel lines will never meet, and the internal angles of a triangle always add up to exactly 180 degrees and it is stated that this is a normal or used to universe

nirvana33 [79]2 years ago

5 0

<span>The meaning of the Big Bang has been very often misunderstood. It is thought that something exploded somewhere and then the exploded part expanded to where we are currently. I hope this did help If not I`m so sorry.</span>

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A substance did not change its chemical nature in a reaction. Which most likely describes the reaction?

Andre45 [30]

B. It was hit with a hammer.

4 0

3 years ago

Read 2 more answers

Glaciers begin with snowfall building up and __________________ the ice. (Choose the best answer)

Allisa [31]

Answer:

compacting

Explanation:

i don't think there is very much explanation, the snow falls and compacts the ice to become giant lol

4 0

3 years ago

An electron and a proton each have a thermal kinetic energy of 3kBT/2. Calculate the de Broglie wavelength of each particle at a

S_A_V [24]

Answer:

Given:

Thermal Kinetic Energy of an electron, $KE_{t} = \frac{3}{2}k_{b}T$

$k_{b} = 1.38\times 10^{- 23} J/k$ = Boltzmann's constant

Temperature, T = 1800 K

Solution:

Now, to calculate the de-Broglie wavelength of the electron, $\lambda_{e}$ :

$\lambda_{e} = \frac{h}{p_{e}}$

$\lambda_{e} = \frac{h}{m_{e}{v_{e}}$ (1)

where

h = Planck's constant = $6.626\times 10^{- 34}m^{2}kg/s$

$p_{e}$ = momentum of an electron

$v_{e}$ = velocity of an electron

$m_{e} = 9.1\times 10_{- 31} kg$ = mass of electon

Now,

Kinetic energy of an electron = thermal kinetic energy

$\frac{1}{2}m_{e}v_{e}^{2} = \frac{3}{2}k_{b}T$

$}v_{e} = \sqrt{2\frac{\frac{3}{2}k_{b}T}{m_{e}}}$

$}v_{e} = \sqrt{\frac{3\times 1.38\times 10^{- 23}\times 1800}{9.1\times 10_{- 31}}}$

$v_{e} = 2.86\times 10^{5} m/s$ (2)

Using eqn (2) in (1):

$\lambda_{e} = \frac{6.626\times 10^{- 34}}{9.1\times 10_{- 31}\times 2.86\times 10^{5}} = 2.55 nm$

Now, to calculate the de-Broglie wavelength of proton, $\lambda_{e}$ :

$\lambda_{p} = \frac{h}{p_{p}}$

$\lambda_{p} = \frac{h}{m_{p}{v_{p}}$ (3)

where

$m_{p} = 1.6726\times 10_{- 27} kg$ = mass of proton

$v_{p}$ = velocity of an proton

Now,

Kinetic energy of a proton = thermal kinetic energy

$\frac{1}{2}m_{p}v_{p}^{2} = \frac{3}{2}k_{b}T$

$}v_{p} = \sqrt{2\frac{\frac{3}{2}k_{b}T}{m_{p}}}$

$}v_{p} = \sqrt{\frac{3\times 1.38\times 10^{- 23}\times 1800}{1.6726\times 10_{- 27}}}$

$v_{p} = 6.674\times 10^{3} m/s$ (4)

Using eqn (4) in (3):

$\lambda_{p} = \frac{6.626\times 10^{- 34}}{1.6726\times 10_{- 27}\times 6.674\times 10^{3}} = 5.94\times 10^{- 11} m = 0.0594 nm$

7 0

3 years ago

Please help with these questions. All questions are in the image.

S_A_V [24]

1) Average speed

2) Displacement

Explanation:

Speed is a scalar quantity which gives a measure of how fast a body is moving. It is equal to the ratio between the distance travelled by an object and the time taken to cover that distance:

$speed = \frac{d}{\Delta t}$

where

d is the distance covered

$\Delta t$ is the time taken

It is important to note that being a scalar, speed does not have any direction. Moreover, distance is also a scalar quantity, which corresponds to the total length of the path covered by the object, regardless on the direction taken.

So, the equation "travelled distance/elapsed time" corresponds to the average speed. (where the term average refers to the fact we are not measuring the speed at a specific instant in time, but on a certain time interval $\Delta t$ .

Velocity is a vector quantity, so it has both a magnitude and a direction.

The magnitude of the velocity is given by:

$velocity=\frac{\Delta x}{\Delta t}$

where

$\Delta x$ is the change in position (or displacement) of the object

$\Delta t$ is the time taken

And the direction of the velocity corresponds to the direction of the displacement.

We must note that while distance does not depend on the direction, displacement does. In fact, displacement measures the difference between the initial and final position of the object.

Therefore, the equation "change in position / elapsed time" is equal to the average velocity.

Learn more about speed and velocity:

brainly.com/question/8893949 (speed)

brainly.com/question/5063905 (speed vs velocity)

brainly.com/question/5248528 (velocity)

#LearnwithBrainly

4 0

3 years ago

The number 3 in hydrogen in NH33 is the

frosja888 [35]

Answer:

no of atoms