Answer:
[tex]n=1.86*10^{-30}m^3[/tex]
Explanation:
From the question we are told that:
Fermi energy of conduction electrons [tex]E_f=0.548J[/tex]
Generally the equation for Fermi energy is mathematically given by
[tex]E_f=\frac{3}{\pi}^2/3*\frac{h^2}{8m}*{n^{2/3}}[/tex]
[tex]E_f=\frac{3}{\pi}^2/3*\frac{h^2}{8m}*{n^{2/3}}[/tex]
[tex]{n^{2/3}}=\frac{E_f}{\frac{3}{\pi}^2/3*\frac{h^2}{8m}}[/tex]
Where
h= Planck's constant
[tex]{n^{2/3}}=\frac{E_f}{\frac{3}{\pi}^2/3*\frac{h^2}{8m}}[/tex]
[tex]{n^{2/3}}=\frac{0.548J}{3.62*10^{-19}}[/tex]
[tex]n=(1.51*10^{-20})^{3/2}[/tex]
[tex]n=1.86*10^{-30}m^3[/tex]
how many different plant and animal species can be found in tropical rainforests
PLEASE ANSWER BY TODAY!
A, A couple hundred
B, 100 thousand.
C, 10 thousand.
D, Millions.
Answer:
Correct answer is B.
Explanation:
The world's most ecologically diverse terrestrial ecosystems are tropical rainforests. The Amazon rainforest is the largest tropical rainforest on the planet. Around 40,000 plant species, approximately 1,300 bird species, 3,000 fish species, 427 animal species, and 2.5 million insect species call it home.In total around 100 thousand different plant and animal species can be found in tropical rainforests.
Learn more about species here:
https://brainly.com/question/23445324
#SPJ2
If we want to reach the planet PSR B1620-26 b, explain why we will need to make some big “wrinkle in time” discoveries or find ways to live much, much longer?
Answer:
Given the information that PSR B1620-26 b is the oldest planet in the Milky Way, it is estimated to be about 13 billion years old, the planet is approximately 12,390 light-years away from Earth, this means that it would take 460,908,000 years to arrive at the ancient planet. If we want to reach this planet, we are going to need to make some gig “wrinkle in time” discoveries, or find ways to live much longer, considering that the current lifespan of humans is only 79 years.
a crane lifts a 450kg concrete to the top of a 50m building in 5s.assuming g=10m/s²,calculate a,the potential energy if the concrete
Answer:
The answer is 225,000Joules
1. When energy is transformed from one form to another it is called
A. transformation of energy
B. conservation of energy
C. consumed energy
D. wasted enenergy
Answer:
A)
Explanation:
Energy transformation is when energy changes from one form to another.
it is possible for an excited hydrogen atom to return to the ground state by the emission of a single photon. regardless of the initial excited state, this electron transition produces a spectral line in which region of the electromagnetic spectrum?
1. ultraviolet
2. infrared
3. visible light
4. radio waves
Answer:
1. Ultraviolet
Explanation:
This is called the Balmer series. Transitions ending in the ground state (n = 1) are called the Lyman series, but the energies released are so large that the spectral lines are all in the ultraviolet region of the spectrum.
It is possible for an excited hydrogen atom to return to the ground state by the emission of a single photon. Regardless of the initial excited state, this electron transition produces a spectral line in ultraviolet region of the electromagnetic spectrum. The correct option is 1.
What is electromagnetic spectrum?An electromagnetic spectrum is the spectrum consisting of the colors of radiation of a white light with different wavelengths.
It is possible for an excited hydrogen atom to return to the ground state by the emission of a single photon.
The transitions which ends in the ground state (n = 1) are termed as Lyman series. Energy released is large in amount so that the spectral lines fall in the ultraviolet region of the spectrum.
Thus, regardless of the initial excited state, this electron transition produces a spectral line in ultraviolet region of the electromagnetic spectrum. The correct option is 1.
Learn more about electromagnetic spectrum.
https://brainly.com/question/23727978
#SPJ2
Find the height of a cylinder with a volume of 220inand a radius of 3 inches. Round
your answer to the nearest hundredth.
07.78 inches
6.93 inches
5.00 inches
9.84 inches
[tex]\huge{ \mathcal{ \underline{ Answer} \: \: ✓ }}[/tex]
Given :
volume = 220 in³radius = 3 inSolution :
[tex] \large\boxed{ \mathrm{volume = \pi {r}^{2}h }}[/tex]
[tex]220 = \dfrac{22}{7} \times 3 \times 3 \times h[/tex][tex] \dfrac{220 \times 7}{22 \times 3 \times 3} = h[/tex][tex] \dfrac{10 \times 7}{3 \times 3} = h[/tex][tex]h = \dfrac{70}{9} [/tex][tex] \boxed{h \: = 7.78 \: \: in}[/tex]_____________________________
[tex]\mathrm{ \#TeeNForeveR}[/tex]
Answer:
0.078 inches
Explanation:
The volume of a cylinder is [tex]V=\pi r^{2} h[/tex]. [tex]r[/tex] is the radius of the cylinder, [tex]h[/tex] is the height of the cylinder, and [tex]V[/tex] is the total volume.We can divide both sides by [tex]9\pi[/tex] to isolate the height. We now have [tex]\frac{220}{9\pi }=h[/tex].We can plug in [tex]220[/tex] for the value of [tex]V[/tex], and insert 3 as [tex]r[/tex]. Now, we have [tex]220 = \pi (3^2)(h)[/tex].We can simplify the right side by finding the value of [tex]3^2[/tex], which is [tex]3*3[/tex], or [tex]9[/tex]. We now have [tex]220 = 9\pi h[/tex].Divide both sides by [tex]9\pi[/tex] so we can isolate the height! We now have [tex]\frac{220}{9\pi }=h[/tex].It would be best to use a calculator at this point. Plug the above equation into a calculator; otherwise, replace [tex]\pi[/tex] with [tex]3.14[/tex] and simplify the fraction. You should get about [tex]07.7809...[/tex] which we can round to the nearest hundredths (since this is Geometry, I am assuming you know how to round).Our final answer is [tex]07.78[/tex] inches.Hopefully this was of use!
A car has a mass of 2,000 kg and is traveling at 28m/s. What is the car’s kinetic energy?
984,000 J
784,000 J
484,000 J
Answer: i am not sure
Explanation: i am not sure
What was the initial velocity of a rock throw upwards if the velocity after 8 s is 90m/s?
Answer:
Initial velocity of rock = 11.6 m/s
Explanation:
Given:
Final velocity of rock = 90 m/s
Time taken by rock = 8 seconds
Find:
Initial velocity of rock
Computation:
Using first equation of motion;
v = u + at
For rock
v = u + gt
Acceleration due to gravity = 9.8 m/s²
90 = u + (9.8)(8)
90 = u + 78.4
u = 90 - 78.4
u = 11.6
Initial velocity of rock = 11.6 m/s
The low point of a transverse wave is called a
crest
trough
rarefaction
compression
Which activities will help improve your flexibility? A. Yoga B. Dance C. Pilates D. All of the above
Answer: I believe that the answer is D.
Explanation:
Hope this helps and have a great day! :)
Answer:
D) all of the above
Explanation:
The elements neon and argon are not reactive
What is the wave length of the instruments playing at this frequency if the speed of sound is 342m/s
Answer:
6.84m
Explanation:
The question you asked didn't specify the frequency of the instrument, so I'm going to assume for the question sake.
For the question, we will use the formula
λ = V/F, where
λ = the wavelength we're looking for
V = Velocity of the sound
F = frequency of sound.
Assuming that the frequency of the instrument is 50Hz.
λ = 342/50
λ = 6.84 m
Un circuito que contiene una batería de 6.0 V se conecta con un resistor de 81.0 Ω. Si después de media hora el voltaje de la batería disminuye a 4.5 V, cómo cambia la corriente en el circuito respecto al principio
Answer:
AI = 0.019 A
Explanation:
The computation of the current change and the same compared to the staring is shown below;
I = v ÷ R
= 5v ÷ 81.0
I = 0.074 A
Now
I = v ÷ r
= 6v ÷ 81.0
I = 0.055A
Now
I = 0.074A - 0.055A
AI = 0.019 A
The same would be considered
Much of the pollution in out oceans comes from:
a.) car exhaust
b.) organic pesticides
c.) sewage and industrial waste
d.) fumes and smog
Answer:
c.) sewage and industrial waste
Which of the following situations would have the fastest speed?
Sound in a vacuum
Light in a vacuum
Sound in a solid
Light in a solid
sound in vacuum
Explanation:
because as u turn a vacuum on it make noise instant when u make sound from a solid object it takes a while to do thing starting slow then going fast in different objects
1. Which of the following is
a reason you should drink water everyday?
A. Water praites uitamins.
B. Water proldes nutrients for daily functions
c Water praides energy
D. Water helps ashion gons and the spinal
cord
.
Answer:
B
Explanation:
Water is essential to most bodily functions.
According to the law of reflection, what is the angle of incidence?
It is the angle the incident ray makes with a line drawn perpendicular to the viewer.
It is the angle the incident ray makes with a line drawn perpendicular to the reflecting surface.
It is the angle the incident ray makes with a line drawn parallel to the reflecting surface.
Answer:
It is the angle the incident ray makes with a line drawn perpendicular to the reflecting surface
(Ecology) Food Chain lab Gizmo:
Before you interact with the simulation, what are your expecations? How will the food chain be effected if one organisim's population is altered? In your response, select one organisim (grass, rabbit, snake, hawk) and give a 3 sentence response on how you think a change in population of this organisim will impact the rest of the food chain.
Answer:
If the population of rabbits was altered then the food chain would be affected because if the population decreased then the animals that prey on rabbits wouldn't have as much food as they used to so the predators of the rabbits would decrease. If the population increased then the animals that prey on rabbits would increase. Overall, if rabbits had a change in population then the food chain would become effected, because if rabbits decrease then their predators decrease in population as well, the same goes for an increase in population.
(hope this helped!)
Can work ever be negative?
A)Yes, when force is negative
B)Yes, when displacement is negative
C)Yes, when cos(e) is negative
D)No, work can never be negative
Answer:
B yes when displacement is negative
q=mcAt
Calculate the amount of heat gained by 114.32 grams of water at 14.85C raised to 18.0C. The heat capacity of water is 4186J/kgC.
Answer:
1.51 × 10⁶ kJ
General Formulas and Concepts:
Stoichiometry
Using Dimensional AnalysisThermochemistry
Specific Heat Formula: q = mcΔT
q is heat (in J)m is mass (in g)c is specific heat formula (in J/g °C)ΔT is change in temperature (in °C)Explanation:
Step 1: Define
[Given] m = 114.32 g
[Given] c = 4186 J/kg °C
[Given] ΔT = 18.0 °C - 14.85 °C = 3.15 °C
[Solve] q
Step 2: Convert Pt. 1
1 kg = 1000 g
[tex]\displaystyle 4186 \ J/kg \ ^\circ C(\frac{1000 \ g}{1 \ kg}) = 4186000 \ J/g \ ^\circ C[/tex]
Step 3: Solve
Substitute in variables [Specific Heat Formula]: q = (114.32 g)(418600 J/g °C)(3.15 °C)Multiply: q = (4.78544 × 10⁸ J/°C)(3.15 °C)Multiply: q = 1.50741 × 10⁹ JStep 4: Convert Pt. 2
1000 J = 1 kJ
[tex]\displaystyle 1.50741 \cdot 10^9 \ J(\frac{1 \ kJ}{1000 \ J}) = 1.50741 \cdot 10^6 \ kJ[/tex]
Step 5: Check
Follow sig fig rules and round. We are given 3 sig figs as our lowest.
1.50741 × 10⁶ kJ ≈ 1.51 × 10⁶ kJ
Volcanoes often form belts along plate boundaries. How does the piece of art illustrate that this statement holds true for North America? explain.
Answer:
The formation of volcanic arcs, trenches and subsidence leads to the production of volcanic eruptions.
Explanation:
North America plate makes a convergent boundary along with the pacific oceans. The is man reason for the development of the volcanoes and the origin of the earthquakes. The collusion of both these pales leads to the formation of a volcanic ring of fire that can be seen in the pacific ocean.The______is the particle in the nucleus with a positive charge.
Answer here
Answer:
proton proton proton proton
Which is true according to the law of conservation of energy?
ОА.
In a closed system, the total amount of energy in the universe keeps on changing
The supply of energy is limited, so it is essential to conserve it.
OB.
OC.
In a closed system, energy can be created and destroyed.
0In a closed system, energy cannot be used faster than it is created
O E.
In a closed system, the total energy always remains constant OD
Answer: Last option (total energy always remains constant)
Explanation:
The Law of Conservation basically states that energy cannot be created or destroyed. Only changed from one form to another (potential, kinetic, chemical, etc.) so it makes sense that the net energy is unchanging.
7. What is the force on a 1000 kg elevator that is falling freely under the acceleration of gravity
only (10m/s?)?
How might variation in the color of beetles help them survive ?
Answer:
they can blend in with their suroundings
Explanation:
Linus builds an electrical circuit with a battery and with wires that carry the current. As the battery weakens, the current also weakens.
How does this affect the magnetic field around the wires?
The field gets stronger.
The field gets weaker.
The field changes direction.
The field disappears completely.
Answer:
The field gets weaker
Explanation:
I’m taking the test right now, hope this helps!!
Answer:
Linus builds an electrical circuit with a battery and with wires that carry the current. As the battery weakens, the current also weakens.
so, it would be B
Two resistors, one with 7.00 Ω of resistance and the other with 11.00 Ω of resistance, are connected in series to a 9.00 V battery. How much power is dissipated by these two resistors?
Answer:
4.5 W
Explanation:
Applying,
P = V²/(R₁+R₂).................. Equation 1
Where P = Power, V = Voltage, R₁ and R₂ = values of the two resistor.
From the question,
Given: V = 9.00 V, R₁ = 7.00 Ω, R₂ = 11.00 Ω
Substitute these values into equation 1
P = 9²/(7+11)
P = 81/(18)
P = 4.5 Watt.
Hence the power dessipated by the two resistors is 4.5 watt
What kind of energy was used to move the toy car?
Answer:
kinetic energy
Explanation:
Motors change electrical energy into kinetic energy. The spinning movement of the motor is used to do work, for example, the wheels on a toy car.
Answer:
hope this works
Explanation:
Kinetic energy is defined as the energy of a moving object.
A thrown football, a speeding automobile, a marathon runner, or a rock falling from a cliff, are examples of objects that have kinetic energy.
acentripetal = var
1). A car goes around a curve at 20 m/s. If the radius of the curve is 25 m, what is
the centripetal acceleration of the car?
1. Picture
2. Knowns/Unknowns:
4. Substitution
E
25.0m
W
S
6. Units
3. Formula
5. Solution
anotant speed of 8 m/s in a vertical circle of
Answer:
Centripetal acceleration = 16 m/s²
Explanation:
Given the following data;
Velocity = 20 m/s
Radius, r = 25 m
To find the centripetal acceleration;
Mathematically, centripetal acceleration is given by the formula;
Centripetal acceleration = velocity²/radius
Centripetal acceleration = 20²/25
Centripetal acceleration = 400/25
Centripetal acceleration = 16 m/s²
True or False. Can Metalloids conduct electricity under certain conditions?
Answer:
Conduction: Some metalloids, such as silicon and germanium, can act as electrical conductors under the right conditions, thus they are called semi-conductors. Luster: Silicon for example appears lustrous, but is not malleable or ductile (it is brittle - a characteristic of some nonmetals).
Explanation: