Complete Question
(A) Find the excitation energy from the ground level to the third excited level for an electron confined to a box that has a width of 0.125 nm .
(B) The electron makes a transition from the n=1 to n= 4 level by absorbing a photon. Calculate the wavelength of this photon.
Answer:
A
[tex]\Delta E = 337 \ eV[/tex]
B
[tex]\lambda = 3.439 *10^{-9} \ m[/tex]
Explanation:
Considering question a
From the question we are told that
The width of the box is [tex]w = 0.125 \ nm = 0.125 *10^{-9} \ m[/tex]
Generally the energy level of a particle confined to a box is mathematically represented as
[tex]E_n = \frac{n^2 h^2}{8 m L^2 }[/tex]
Generally the excitation energy is mathematically represented as
[tex]\Delta E = \frac{h^2 }{ 8 m L^2 } [n_2^2 - n_1 ^2 ][/tex]
From the question [tex]n_2 = 3\ (Third \ excited \ level ) \ \ and \ \ n_1 = 1[/tex]
Here h is the Planck's constant with a value of [tex]h = 6.62607015 * 10^{-34} J \cdot s[/tex]
m is the mass of electron with value [tex]m = 9.11 *10^{-31} \ kg[/tex]
So
[tex]\Delta E = \frac{[6.62607015 * 10^{-34} ]^2 }{ 8 * (9.11 *10^{-31}) (0.125 *10^{-9})^2 } [3^2 - 1^2 ][/tex]
=> [tex]\Delta E = 539 *10^{-19} \ J[/tex]
=> [tex]\Delta E = \frac{539 *10^{-19}}{1.60 *10^{-19}} \ J[/tex]
=> [tex]\Delta E = 337 \ eV[/tex]
Considering question b
Generally the energy level of a particle confined to a box is mathematically represented as
[tex]E_n = \frac{n^2 h^2}{8 m L^2 }[/tex]
Generally the excitation energy is mathematically represented as
[tex]\Delta E = \frac{h^2 }{ 8 m L^2 } [n_2^2 - n_1 ^2 ][/tex]
From the question [tex]n_2 = 4 \ \ and \ \ n_1 = 1[/tex]
Here h is the Planck's constant with a value of [tex]h = 6.62607015 * 10^{-34} J \cdot s[/tex]
m is the mass of electron with value [tex]m = 9.11 *10^{-31} \ kg[/tex]
So
[tex]\Delta E = \frac{[6.62607015 * 10^{-34} ]^2 }{ 8 * (9.11 *10^{-31}) (0.125 *10^{-9})^2 } [4^2 - 1^2 ][/tex]
=> [tex]\Delta E = 578 *10^{-19} \ J[/tex]
=> [tex]\Delta E = \frac{ 578 *10^{-19}}{1.60 *10^{-19 }}[/tex]
=> [tex]\Delta E = 361.45 \ eV[/tex]
Gnerally the wavelength is mathematically represented as
[tex]\lambda = \frac{hc}{\Delta E }[/tex]
=> [tex]\lambda = \frac{ 6.626 *10^{-34} * (3.0 *10^{8})}{578 *10^{-19} }[/tex]
=> [tex]\lambda = 3.439 *10^{-9} \ m[/tex]
In 1940, it was discovered that uranium could be artificially changed to plutonium, a process called transmutation. What combination of decay processes would convert U-239 (92 protons) into Pu-239 (94 protons)?
A. Beta-decay followed by beta decay.
B. Positron emission followed by electron capture.
C. Electron capture followed by alpha decay.
D. Alpha decay followed by beta decay.
The combination of decay processes that would convert U-239 into PU- 239 is beta decay followed by another beta decay. There are two different types of beta decay (positive and negative beta decays) they both occur simultaneously in order to move the atoms towards stability.
What do your observations show you about the forces exerted on objects in a collision?
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I would appreciate some help for this worksheet question
Answer:
a) [tex]v(2.5\,s) = 40\,\frac{m}{s}[/tex], b) [tex]v(3.5\,s) = -60\,\frac{m}{s}[/tex], c) [tex]v(4.5\,m) = 0\,\frac{m}{s}[/tex], d) [tex]v(7.5\,s) = 60\,\frac{m}{s}[/tex]
Explanation:
Mathematically speaking, the instantaneous velocity is the slope of the curve, which can be estimated by means of the definition of secant line, equivalent to the definition of average velocity:
[tex]v(t) = \frac{x(t+0.5\,s)-x(x-0.5\,s)}{(t+0.5\,s)-(t-0.5\,s)}[/tex] (1)
Where:
[tex]x(t+0.5\,s)[/tex], [tex]x(t-0.5\,s)[/tex] - Position of the particle at [tex]t +0.5\,s[/tex] and [tex]t-0.5\,s[/tex], measured in meters.
[tex]t[/tex] - Time, measured in seconds.
Now we proceed to calculate each instantaneous velocity:
a) [tex]t = 2.5\,s[/tex]
[tex]v(2.5\,s) = \frac{x(3\,s)-x(2\,s)}{3\,s-2\,s}[/tex]
[tex]v(2.5\,s) = \frac{120\,m-80\,m}{1\,s}[/tex]
[tex]v(2.5\,s) = 40\,\frac{m}{s}[/tex]
b) [tex]t = 3.5\,s[/tex]
[tex]v(3.5\,s) = \frac{x(4\,s)-x(3\,s)}{4\,s-3\,s}[/tex]
[tex]v(3.5\,s) = \frac{60\,m-120\,m}{1\,s}[/tex]
[tex]v(3.5\,s) = -60\,\frac{m}{s}[/tex]
c) [tex]t = 4.5\,s[/tex]
[tex]v(4.5\,s) = \frac{x(5\,s)-x(4\,s)}{5\,s-4\,s}[/tex]
[tex]v(4.5\,s) = \frac{60\,m - 60\,m}{1\,s}[/tex]
[tex]v(4.5\,m) = 0\,\frac{m}{s}[/tex]
d) [tex]t = 7.5\,s[/tex]
[tex]v(7.5\,s) = \frac{x(8\,s)-x(7\,s)}{8\,s-7\,s}[/tex]
[tex]v(7.5\,s) = \frac{0\,m - (-60\,m)}{1\,s}[/tex]
[tex]v(7.5\,s) = 60\,\frac{m}{s}[/tex]
If you are holding a stack of books at your waist and then you walk across the room your hands did?
Answer: 3) work
Explanation:
Work is doing something that requires you to expend energy. In walking across the room while your hands were carrying the stack of books, you expended energy through them which means that they did work.
We can neither tell the efficiency nor the power taken to do the work above from the given information. And by moving and holding books, there was definitely work done which means that all options apart from 3 are false.
Which of the following statements about elements and atoms is true?
A. Atoms are the smallest unit of an element.
B. Atoms are made of particles called elements.
C. Elements are made of more than one type of atom.
D. Elements are changed into atoms by a chemical reaction.
hmu^^^^
Answer:
A. Atoms are the smallest unit of an element.
Explanation:
The correct statement from the given choices is that atoms are the smallest unit of an element.
Atoms are the smallest particles that takes part in chemical reactions and they are made up of protons, neutrons and electrons.
Elements are distinct substances that cannot be split up into simpler substances. They are made up of only one kind of atoms. Elements are not changed into atoms by chemical reactions. In chemical reactions, atoms simply recombine.Which change to an object would double its potential energy?
OA. Increasing its mass to four times its original value
O B. Reducing its mass to one-half of its original value
OC. Reducing its height to one-half of its original value
OD. Increasing its height to twice its original value
HELPPPPP!!! PLZ
Answer: The answer is D! Hope this helps!
Explanation:
Answer:
It’s D for ape.x
Explanation:because I’m smarttttttt
What is black body radiation? Explain in detail.
An object that absorbs all radiation falling on it, at all wavelengths, is called a black body. When a black body is at a uniform temperature, its emission has a characteristic frequency distribution that depends on the temperature. Its emission is called black-body radiation
hope it helps
How much is a ball that is tethered to a post accelerating if its linear speed is 3.5 m/s and the ball is 0.91 meters away from the pole? a = v^2 / r
Answer:
[tex]a_{c} = 13.46\ m/s^2[/tex]
Explanation:
The motion of the tethered ball around the pole can be modeled as uniform circular motion. The acceleration of the objects executing uniform circular motion is due to the change in direction of their velocity. This is called centripetal acceleration. It is given by the following formula:
[tex]a_{c} = \frac{v^2}{r}[/tex]
where,
ac = centripetal acceleration = ?
v = speed of ball = 3.5 m/s
r = distance of ball from center of rotation = 0.91 m
Using these values in equation, we get:
[tex]a_{c} = \frac{(3.5\ m/s)^2}{0.91\ m}\\\\a_{c} = 13.46\ m/s^2[/tex]
A mechanic uses a lift to raise an 11,760 N car 0.50m off the ground. How much work does the lift do on the car?
Answer:
5880 JExplanation:
The work done by an object can be found by using the formula
workdone = force × distance
From the question we have
workdone = 11760 × 0.5
We have the final answer as
5880 JHope this helps you
did sans from Undertale really die or was he just trolling
Answer:
I think he was just trolling.
Explanation:
They don't give out any good reasons or evidence about him dying. I think they are just pretending. You tell me tho.... Many people think he did die, while others think that he didnt.
What do you think?!
A teammate starts taking an all-natural supplement to improve strength and body shape and recommends you take it, too. This is an example of
Answer:
Explanation:
online personal fittness
A 430.0 g mass is being pushed by a 1.1 N net force. What is the acceleration?
Answer:
[tex]a = 2.56\ m/s^2[/tex]
Explanation:
Mechanical Force
According to the second Newton's law, the net force exerted by an external agent on an object of mass m is:
F = m.a
Where a is the acceleration of the object.
The object has a mass of m=430 g = 0.43 Kg and is pushed by a net force of F=1.1 N. To calculate the acceleration, we solve for a:
[tex]\displaystyle a=\frac{F}{m}[/tex]
[tex]\displaystyle a=\frac{1.1}{0.43}[/tex]
[tex]\mathbf{a = 2.56\ m/s^2}[/tex]
Helping me please What can smart modern biosensors be used in heath applications?
Answer: Biosensors are modern electronic devices which are made up of biological recognition system and a transducer, for processing of signals and to quantify a particular analyte.
Explanation:
In modern medicine, a Biosensors are used to replace some clinical laboratory investigations of biological fluids with the advantages of being easy to use, rapid and robust as well as offering multianalyte testing capability. They are classified based on their biological recognition elements which includes:
--> enzymatic biosensors
--> immuno biosensors
--> DNA and whole cell biosensors.
They can also be classified according to their signal transduction methods. These includes:
--> electrochemical Biosensors,
--> optical biosensors,
--> thermal and mass-based biosensors;
Some of the HEALTH APPLICATIONS of a modern biosensor includes:
--> Monitoring of glucose levels in diabetic patients which makes use of enzyme based sensors to monitor concentration of glucose in patients.
--> Detection of general metabolic status of bacteria, fungi, yeast, animal or plant cells.
--> Monitoring of cholesterol levels to prevent cardiovascular diseases. Cardiac troponin and. C - Reactive Proteins are biomarkers that are easily detected using biosensors.
--> They are used for Cancer clinical testings
Electrical equipment in an office takes a current of 13 A from a 240 V supply.
Estimate the cost per week of electricity if the equipment is used for 30 hours each
week and 1 kWh of energy costs Rm0.50
Answer:
The cost per week of electricity is Rm 46.8
Explanation:
Electrical Power and Energy
The electrical power consumed by an appliance connected to a voltage V and carrying a current I is given by:
P = V.I
The energy consumed by an electrical appliance of power P during a time t is:
E = P.t
The electrical equipment in an office takes I=13 A when connected to a V=240 V supply.
The power consumed is:
P = 240 V * 13 A
P = 3,120 Watt
Converting to Kilowatt:
P = 3,120/1,000 KW
P = 3,12 KW
If the equipment is used t=30 hours each week, the energy is:
E = 3.12 KW * 30 h
E = 93.6 KWh
Since the cost of each KWh is Rm 0.50, the weekly cost of electricity is:
C = 93.6 * 0.50 = 46.8
The cost per week of electricity is Rm 46.8
1) A rock is thrown downward from the top of a 40.0-m-tall tower with an initial speed of 12 m/s. Assuming
negligible air resistance, what is the speed of the rock just before hitting the ground?
Answer:
By using [tex]v^{2}_{f} = v^{2}_{i} + 2a\Delta y[/tex], with [tex]v_{i} = -12m/s[/tex] and [tex]\Delta y = -40m[/tex]:
[tex]v^{2}_{f} = v^{2}_{i} + 2a/Delta y[/tex]
[tex]v^{2} = (-12m/s)^{2} + 2(-9.80m/s^{2})(-40m)[/tex]
[tex]v = -30m/s[/tex]
Explanation:
Hope this helped!
A rock is thrown downward from the top of a 40 m tall tower, with The speed of the rock just before hitting the ground will be equal to -30 m/s.
What is Friction?Friction is the resistance to a thing moving or rolling over another solid object. Although frictional forces can be advantageous, such as the traction required to walk while slipping, they also provide a significant amount of resistance to motion. In order to overcome frictional resistance in the moving parts, about 20% of an automobile's engine power is used.
The forces of attraction, also referred to as adhesion, between the contact zones of the surface, which are always minutely uneven, seem to be the main contributor to friction between metals.
From the given information in the question,
v²(f) = v²(i) + 2aΔy
v² = (-12 m/s)² + 2(-9.8)(-40)
v = -30 m/s.
Therefore, the velocity of the rock is -30 m/s.
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3 women push a stalled car. Each woman pushes with a 425 N force. What is the mass of the car if the car accelerates at 0.85 m/s2?
Answer:
1500kg
Explanation:
Assuming that the women push the car in the same direction, then the total force is:
Fnet = 425 N ⋅ 3
= 1275 N
To find the mass, we use Newton's second law of motion, which states that,
F = ma
where:
·F is the force applied in newtons
·m is the mass of the object in kilograms
·a is the acceleration of the object in meters per second squared.
So we get:
F
m= ⁻⁻⁻⁻⁻
a
1275N
= ⁻⁻⁻⁻⁻⁻⁻⁻⁻⁻⁻⁻⁻⁻
0.85 m/s²
= 1500 kg
If a paratroopers legs have enough strength to support five times her weight, and they can do so over a travel distance of 0.5 m as they flex, from what height can she free fall to a solid surface without injury
Answer: the required height is 2.5 m
Explanation:
given the given data in question
Lime to come in rest;
using S = ((U1 + U2)/2) t
⇒ 0.5 = ((√(2gh) + 0)/2) t
t = (0.5 × 2) / √(2gh)
now fat = impulse = change in momentum dp
F = 5mg = dp/dt = [(m√(2gh))/(0.5 × 2)] × √(2gh)
5mg = 2mgh/(0.5 × 2)
5 = h / 0.5
h = 5 × 0.5
h = 2.5 m
Therefore the required height is 2.5 m
A food processor draws 8.47 A of current when connected to a potential difference of 110 V.
How much electrical energy is consumed by this food processor monthly (30 days) if it is used on average of 10.0 min every day?
Answer:
27.95[kW*min]
Explanation:
We must remember that the power can be determined by the product of the current by the voltage.
[tex]P=V*I[/tex]
where:
P = power [W]
V = voltage [volt]
I = amperage [Amp]
Now replacing:
[tex]P=110*8.47\\P=931.7[W][/tex]
Now the energy consumed can be obtained mediate the multiplication of the power by the amount of time in operation, we must obtain an amount in Kw per hour [kW-min]
[tex]Energy = 931.7[kW]*30[days]*10[\frac{min}{1day} ]=279510[W*min]or 27.95[kW*min][/tex]
What are some negative impacts of land pollution on humans?
Answer:
Land pollution touches essentially every area of the living world, including: Water that isn't safe to drink. Polluted soil, which leads to a loss of fertile land for agriculture. Climate change, which causes an onslaught of disastrous problems, including flash floods and irregular rainfalls.
Explanation:
HOPE THIS HELPS!!!!!!
Answer:
Look at any ecosystem and there could be multiple forms of contamination—streams full of toxic chemicals from industrial processes, rivers overloaded with nutrients from farms, trash blowing away from landfills, city skies covered in smog. Even landscapes that appear pristine can experience the effects of pollution sources located hundreds or thousands of miles away.
Pollution may muddy landscapes, poison soils and waterways, or kill plants and animals. Humans are also regularly harmed by pollution. Long-term exposure to air pollution, for example, can lead to chronic respiratory disease, lung cancer and other diseases. Toxic chemicals that accumulate in top predators can make some species unsafe to eat. More than one billion people lack access to clean water and 2.4 billion don’t have adequate sanitation, putting them at risk of contracting deadly diseases.
Air pollution brings to mind visions of smokestacks billowing black clouds into the sky, but this pollution comes in many forms. The burning of fossil fuels, in both energy plants and vehicles, releases massive amounts of carbon dioxide into the atmosphere, causing climate change. Industrial processes also emit particulate matter, such as sulfur dioxide, carbon monoxide and other noxious gases. Indoor areas can become polluted by emissions from smoking and cooking. Some of these chemicals, when released into the air, contribute to smog and acid rain. Short term exposure to air pollution can irritate the eyes, nose and throat and cause upper respiratory infections, headaches, nausea and allergic reactions. Long-term exposures can lead to chronic respiratory disease, lung cancer, and heart disease. Long-term exposures also can lead to significant climatic changes that can have far reaching negative impacts on food, water and ecosystems. #SAVE OUR WORLD
how to calculate the speed using time and distance
Answer:
speed = distance/time
Explanation:
distance -> s
speed -> v
time -> t
The calculation of speed using time and distance shows that speed is equal to distance/time.
What is speed?Speed refers to the rate of movement of a vehicle or person.
Thus, the speed can be computed by dividing the total distance by the time consumed.
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My tiger trap needs 735 N of force on top of it to activate. What is the lightest tiger I can trap?
7203 kg
0.013 kg
75 kg
725 kg
Answer:
75kg
Explanation:
[tex]F=mg[/tex]
[tex]m=\frac{F}{g}[/tex]
[tex]m=\frac{735}{9.8}[/tex]
[tex]m=75kg[/tex]
Therefore, the answer is the third option 75 kg
If the forces acting on an object are balanced, what must be true about the motion of the object? (DOK 1, AKS 8b) A. It must be changing direction. B. It must be accelerating. C. It must be moving sporadically. (slowly and then quickly) D. It must have a constant velocity.
Answer:
D
Explanation:
If the forces on an object are balanced (or if there are no forces acting on it), this is what happens: a stationary object stays still a moving object continues to move at the same speed and in the same direction Remember that an object can be moving, even if there are no forces acting on it.
The forces acting on an object are balanced, then it must have a constant velocity. Hence, option D is correct.
What is Force?A strain is a phenomenon that can change an object's velocity in physics. A force can change or increase an excess object's velocity. It makes logical sense to use pushing or pulling to express force. Being vector quantities, energies have both size and direction. Utilizing the SI system, it is calculated in newtons (N). The letter F stands for force.
When forces acting on an item are balanced (or absent), the following occurs: a static object remains still while a moving object maintains its direction and speed. Do not forget that an item can be moving even in the absence of external forces.
When the forces are in equilibrium then it will move in a particular direction also it will move at a constant speed.
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Which of the following types of energy are present at some point in the energy transfer process in a nuclear power plan? Select all that apply.
Heat energy
Geothermal energy
Tidal energy
Hydroelectric energy
Nuclear energy
Electrical energy
Solar Energy
Solar Energy is the answer to the question tell me if i`m wrong
oo hi granger ru online here i have a doubt in physics .
Answer:
.
Explanation:
A 7750 kg space probe, moving nose-first toward Jupiter at 179 m/s relative to the Sun, fires its rocket engine, ejecting 72.0 kg of exhaust at a speed of 230 m/s relative to the space probe. What is the final velocity of the probe?
Answer:
179.47m/s
Explanation:
Using the law of conservation of momentum
m1u1 + m2u2 = (m1+m2)v
m1 and m2 are the masses
u1 and u2 are the initial velocities
v is the final velocity
Substitute
7750(179)+72(230) = (7750+72)v
1,387,250+16560 = 7822v
1,403,810 = 7822v
v = 1,403,810/7822
v= 179.47m/s
Hence the final velocity of the probe is 179.47m/s
A. 230 N
B. 194 N
C. 250 N
D. 340 N
Answer:
I think C 250 it is correct
The maker of an automobile advertises that it takes 13 seconds to accelerate from 5 kilometers per hour to 65 kilometers per hour. Assuming constant acceleration, compute the acceleration in meters per second per second. Round your answer to three decimal places.
Answer: the acceleration is 1.282 m/s²
Explanation:
Given that;
Time t = 13 sec
Initial velocity U = 5 kmph = (5 × 1000)/(60 × 60) = 1.3888 m/s
final velocity V = 65 kmph = (65 × 1000)/(60 × 60) = 18.0555 m/s
Now we know that;
V = U + at
we substitute
18.0555 = 1.3888 + 13a
18.0555 - 1.3888 = 13a
13a = 16.6667
a = 16.6667 / 13
a = 1.282 m/s²
Therefore the acceleration is 1.282 m/s²
Why do we consider eyes, ears, and fingers as physical sensor
Answer:
because
Explanation:
because we need eye to see if you don't have eyes how you regnise some one
if you have ears how can you know who's voice is who's
if don't have fingers how can you know what your are holding this is why they are called physical sensors
Answer:
because they stimulate our brain and the sensor of human body detect stimuli.
Explanation:
It is difficult to lift a bigger stone than the smaller
stone. why?
plzzz give me short and brillient answer
Q. At what point in a waterfall do the drops of water contain the most kinetic energy ?
1.When they are halfway to the bottom
2.When they reach the bottom of the fall
Answer:
2.When they reach the bottom of the fall
Explanation:
The potential energy of the waterfall is maximum at the maximum height and decreases with decrease in height. Based on the law of conservation of mechanical energy, as the potential energy of the water fall is decreasing with decrease in height of the fall, its kinetic energy will be increasing and the kinetic energy will be maximum at zero height (bottom of the fall).
Thus, the correct option is "2" When they reach the bottom of the fall
