Answer:
ΔE = 1.031 eV
Explanation:
For this exercise let's calculate the energy of the photons using Planck's equation
E = h f
wavelength and frequency are related
c = λ f
f = c /λ
let's substitute
E = h c /λ
let's calculate
E = 6.63 10⁻³⁴ 3 10⁸/1064 10⁻⁹
E = 1.869 10⁻¹⁹ J
let's reduce to eV
E = 1.869 10⁻¹⁹ J (1 eV / 1.6 10⁻¹⁹ J)
E = 1.168 eV
therefore the electron affinity is
ΔE = E - 0.137
ΔE = 1.168 - 0.137
ΔE = 1.031 eV
The electron affinity of thulium in units of electron volts per atom is; ΔE ≈ 1.031 eV
From Planck's equation, we can find the energy of the photons when given wavelength as;
E = hc/λ
Where;
h is Planck's constant = 6.626 × 10⁻³⁴ J.s
c is speed of light = 3 × 10⁸ m/s
λ is wavelength
We are given;
wavelength; λ = 1064 nm = 1064 × 10⁻⁹ m
Thus;
E = (6.626 × 10⁻³⁴ × 3 × 10⁸)/(1064 × 10⁻⁹)
E2 = 1.868 × 10⁻¹⁹ J
Converting to eV gives;
E2 = (1.868 × 10⁻¹⁹)/(1.6 × 10⁻¹⁹)
E2 = 1.1675 eV
We are given E1 = 0.137 eV.
Now, electron affinity is simply change in energy. Thus;
ΔE = 1.1675 - 0.137
ΔE ≈ 1.031 eV
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25 PTS AND BRAINLIEST ANSWER PLEASE HELP ME BEFORE 9 PM
A truck accelerates at a rate of 1 m/s2 for 10 seconds. At that time the truck continues traveling at a constant velocity for the next 20 seconds. The truck then begins to slow down at a rate of -1 m/s2 until it comes to rest.
1.What was the truck’s speed at 10 seconds?
2. How far did the truck travel during the first ten seconds?
3. How far did the truck travel for the whole 30 seconds?
Answer:
I think?
Explanation:
1. 20 seconds
2. 1 mile
3. 3 miles
I think i got it right not sure
Answer:
Explanation:
1m/ 10s^2
5 miles?
15 miles
A branch swept into a Category 3 hurricane has a centripetal acceleration of 0.028 m/s2. Estimate the radius of the storm is wind speeds are
53 m/s
Answer:
Radius, r = 100321.43m or 10.03 * 10^4m
Explanation:
Given the following data;
Acceleration, a = 0.028m/s²
Speed = 53m/s
Centripetal acceleration is given by the formula;
[tex] Acceleration, a = \frac {v^{2}}{r}[/tex]
Substituting into the equation, we have;
[tex] Acceleration, a = \frac {53^{2}}{0.028}[/tex]
[tex] Acceleration, a = \frac {2809}{0.028}[/tex]
Radius, r = 100321.43m or 10.03 * 10^4m
An elephant of mass 100kg stands with all four foots on the ground.Each foot covers an area of 0.04m2.calculate the pressure exerted on the ground.
Answer:
140KG
Explanation:
Which of the following describes the mass of an object precisely ? *
2.34 kg
2.345 kg
2 kg
2.3 kg
Answer:
2.345 would be the most precious because you have more numbers to work with and exact numbers
Your mother has called you on your cell phone and asked you to pick up a few items at the grocery store on your way home. As you heard your mother state each item, which process transferred this information from your sensory memory to your short-term memory so you could jot each grocery item down?
Answer:
Encoding
Explanation:
Encoding is the initial learning of information. Encoding is the process of passing new information coming from sensory input into our brain so that it can be easily retrievable. In a nutshell, it is the sum total of the processes by which external information such as the list of items your mother asked you to pick up at the grocery store to be converted into a manner that can be stored within the brain and recalled later from long-term memory.
Encoding has to do with transferring external stimuli into short term and subsequently long-term memory.
1 point
An Arizona solar power plant is able to produce 24 megawatts, which
serves 6,000 homes. How many watts per home?
40 W
О
400 W
4,000 W
40,000 W
The picture is my question
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how permeable and porous would an aquifer be?
Answer: An aquifer is a body of saturated rock through which water can easily move. Aquifers must be both permeable and porous and include such rock types as a sandstone.
Explanation: However, if these rocks are highly fractured, they make good aquifers.
what is the name of the phobias of space?
Answer:
Astrophobia
Explanation:
heop it help
After she’s finished cooking Emily measures the mass of the dough balls. According to the law of conservation of mass, the mass of the dough bars should be equal to
Answer:
The weight of the dough bars after being cooked.
If a ball has a mass of 224 grams and a volume of 53ml, what is the density of the ball? Please round your answer to the nearest tenth.
Answer:
The answer is 4.2 g/mLExplanation:
The density of a substance can be found by using the formula
[tex]density = \frac{mass}{volume} \\ [/tex]
We have
[tex]density = \frac{224}{53} \\ = 4.2264150943396...[/tex]
We have the final answer as
4.2 g/mL to the nearest tenthHope this helps you
Answer:
The density is 4.2
Explanation:
D=M/V
Density is equal to mass/Volume thus D=M/V
A cheetah can run at a maximum speed 103 km/h and a gazelle can run at a maximum speed of 76.5 km/h. If both animals are running at full speed, with the gazelle 99.3 m ahead, how long before the cheetah catches its prey?
Answer in units of s.
Part 2: The cheetah can maintain its maximum speed for only 7.5 s. What is the minimum distance the gazelle must be ahead of the cheetah to have a chance of escape? (After 7.5 s the speed of cheetah is less than that of the gazelle.)
Answer in units of m.
Answer:
1
[tex] t_a = 13.49 \ s [/tex]
2
The distance is [tex] D = 55.2 \ m [/tex]
Explanation:
From the question we are told that
The maximum speed of the cheetah is [tex]v = 103 \ km/h = 28.61 \ m/s[/tex]
The maximum of gazelle is [tex]u = 76.5 \ km/h = 21.25 \ m/s[/tex]
The distance ahead is [tex]d = 99.3 \ m[/tex]
Let [tex]t_a[/tex] denote the time which the cheetah catches the gazelle
Gnerally the equation representing the distance the cheetah needs to move in order to catch the gazelle is
[tex] v* t_a = d + u* t_a [/tex]
=> [tex] 28.61 t_a = 99.3 + 21.25t_a [/tex]
=> [tex] 7.36 t_a = 99.3 [/tex]
=> [tex] t_a = 13.49 \ s [/tex]
Now at t = 7.5 s
[tex]7.5 v = D+ 7.5u [/tex]
=> [tex] 28.61 * 7.5 = D + 21.25* 7.5 [/tex]
=> [tex] 7.36 * 7.5 =D [/tex]
=> [tex] D = 55.2 \ m [/tex]
Hence the for the gazelle to escape the cheetah it must be 55.2 m
8.98 dm3 of hydrogen gas
is collected at 38.8 °C. Find
the volume the gas will occupy
at -39.9 °C if the pressure
remains constant.
Answer:
6.71dm³
Explanation:
Given parameters:
Initial Volume of hydrogen gas = 8.98dm³
Initial Temperature = 38.8°C; in Kelvin = 38.8 + 273 = 311.8K
Final temperature = -39.9°C; in Kelvin = -39.9 + 273 = 233.1K
Unknown:
Final volume = ?
Solution:
To solve this problem, we apply the Charles's law. It states at;
"The volume of a fixed mass (mole) of a gas varies directly as its absolute temperature if the pressure is constant".
Mathematically;
[tex]\frac{V_{1} }{T_{1} }[/tex] = [tex]\frac{V_{2} }{T_{2} }[/tex]
V and T are temperature values
1 and 2 are the initial and final states
Insert the parameters and solve for V₂
[tex]\frac{8.98}{311.8 }[/tex] = [tex]\frac{V_{2} }{233.1}[/tex]
V₂ x 311.8 = 8.98 x 233.1
V₂ = 6.71dm³
What road would exert the least amount of friction on a car?
A road laid out on an air-hockey table, with a thin coat of ice on the table, and a little bit of oil or lard on top of the ice.
NOTE: The car couldn't actually GO anywhere on this road, because a car needs friction in order to move where you want it to. A car on THIS road would just go wherever the wind blew it.
Ok soo idk what question to ask but one of my friends said tht she was dressing as Harley Quinn and she said i should dress as her too but then i said no i dont rlly dress up of those kind of people but then she started to flip out because i couldnt dress as her?? Should I tell her that not all people can dress the same even if they want to or not? What should I say so she can stop saying things that are rude just bc she is mad and thats not my fault??
Answer:
You should tell her in a nice way that that's just not your style and if she doesnt accept that then maybe you should just not talk to her for a while and let her cool down
Explanation:
Hope this helps
An object is moving with an initial velocity of 5.5 m/s. It is then subject to an acceleration of 2.5 m/s² for 11 s. How far will it have traveled during the time of its acceleration? OML HELP
Answer: 211.75m
Explanation:
Listing everything the question gives you:
Vi = 5.5
a = 2.5
t = 11
ΔX = ?
Then pick a kinematic equation to solve for the missing variable
I used this one: Δx = Vit + [tex]\frac{1}{2} at^2[/tex]
When you plug in all ur variables you get Δx = 211.75m
The object has travelled a distance of 211.75 meters.
We have an object moving with an initial velocity of 5.5 m/s.
We have to determine how far will it have traveled during the time of its acceleration.
What is Acceleration ?The rate of change of velocity with respect to time is called Acceleration.
a = dv/dt
According to the question -
initial velocity = u = 5.5 m/s
acceleration = a = 2.5 m/s²
time = t = 11 seconds
Therefore -
S = ut + [tex]\frac{1}{2} at^{2}[/tex]
S = 5.5 x 11 + 0.5 x 2.5 x 11 x 11
S = 211.75 meters
Therefore, the object has travelled a distance of 211.75 meters.
To solve more questions on Kinematics visit the link below-
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A generalization that uses logical reasoning to make sense of observations is..
Answer:
hiatory
Explanation:
how do you find circular motion?
Answer:
Explanation:
By multiplying the rotational frequency with the circumference we can determine the average speed of the object. The circular velocity formula is expressed as, vc = 2 πr / T. Where in, r denotes the radius of the circular orbit. T is time period.
Answer:
2πr
as we know that the circumference of a circle is 2 * π * r, the arc length of the whole circle is 2πr units. Then using the formula s = r * theta, the angle theta equals the arc length divided by the radius. Therefore theta = 2πr/r = 2π radians.
I hope it will helpful for you
mark as brainest answer
thank you
When a light ray enters water, its velocity is _________.
Answer:
UR ANSWER IS WAVELENGTH
otd-2)A softball is thrown straight up into the air at 25 m/s. if it returns to the thrower after 5.0 seconds, how high did it go?
One way:
The ball returned to the thrower's hand after 5 seconds. It spent 2.5 seconds going up, and 2.5 seconds coming back down.
Use the formula Distance = (1/2) (acceleration) (time squared)
Distance = (1/2) (gravity) (2.5 sec)
Distance = (1/2) (9.8 m/s ²) (6.25 sec² )
Distance = (4.9 m/s²) (6.25 sec²)
Distance = 30.63 meters
Another way:
The thrower threw the ball straight up at 25 m/s.
It sailed upward for 2.5 seconds.
At the top of its trip, before it started falling, its speed was zero.
Its average speed was (1/2) (25+0) = 12.5 m/s
At an average speed of 12.5 m/s for 2.5s, the ball rose (12.5x2.5) = 31.25m.
(Why are the two answers different ?
Because if the ball was thrown straight up at 25 m/s, it would actually return to the thrower in 5.1 seconds, not 5.0 seconds.
So if you use the acceleration of gravity to solve the problem, you get one answer, but if you use 5.0sec to solve it, you get a slightly different one.)
What special name is given to group II elements in the periodic table?
Answer:
Alkaline earth metals.
Explanation:
For e.g The metals of group ll are: Be, Mg, Ca, etc
Tech A says that when checking a voltage drop across an open switch, a measurement of 12 volts is normal. Tech B says that when checking voltage drop across an open switch, a measurement of 12 volts means there are 12 volts on each side of the switch. Who is correct
Answer:
Tech B is correct.
Explanation:
The voltage drop between the two terminals of a circuit is the measurement of the potential difference between the two terminals.
If [tex]v_1[/tex] and [tex]v_2[/tex] ( assuming [tex]v_1 > v_2[/tex]) are potentials at terminal 1 and terminal 2 of the given open circuit.
According to A, the measurement of the potential drop is 12 volts, i.e
The measurement of potential difference [tex]=v_1 -v_2[/tex]
= 12 volts which is correct.
But according to B, a measurement of 12 volts means there are 12 volts on each side of the switch ([tex]v_1= 12[/tex] volts and [tex]v_2=12[/tex] volts), i.e
According to the claim of B, the potential difference (or drop) across the terminals is
[tex]v_1-v_2= 12-12=0[/tex] but the measured potential drop is 12 volts, so B is wrong.
Hence, Tech B is correct.
to avoid an accident, a driver with a mass of 60kg applies his brakes and decelrates from 30m/s to 1m/s in 2 seconds. how much force was absorbed by his seat belt
Answer:
[tex]F=-870\ N[/tex]
Explanation:
Net Force
The net force applied to an object of mass m that moves at an acceleration a is given by:
F=m.a
The acceleration can be calculated by the equations of the constant acceleration motion:
[tex]\displaystyle a=\frac{v_f-v_o}{t}[/tex]
Where vf is the final speed, vo is the initial speed, and t is the time.
Substituting the given values:
[tex]\displaystyle a=\frac{1-30}{2}=\frac{-29}{2}=-14.5\ m/s^2[/tex]
The force absorbed by his seat belt:
[tex]F=60\ kg\cdot (-14.5\ m/s^2)[/tex]
[tex]\boxed{F=-870\ N}[/tex]
Force absorbed by the seatbelt is : 870 N
Given data :
mass of body = 60 kg
Initial velocity ( V₁ ) = 30 m/s
Final velocity ( V₂ ) = 1 m/s
Time = 2 secs
Determine the force absorbed by the seat belt
Force = Mass * acceleration --- ( 1 )
where ;
acceleration = Δ v / t ---- ( 2 )
Δ v = ( 30 - 1 ) = 29 m/s
t = 2 secs
Back to equation ( 2 )
acceleration = 29 / 2 = 14.5 m/s²
∴ Force exerted on seatbelt
F = m * a
= 60 kg * 14.5 m/s² = 870 N
Hence we can conclude that the force absorbed by his seatbelt is 870 N
Learn more : https://brainly.com/question/24953628
Write a statement that explains the relationship among velocity, speed, and direction.
Answer:
velocity is the speed and direction of a moving object
Explanation:
that is basicaly the defention
How much force is required to accelerate a 0.145 kg baseball to 150 m/s2?
Which type of intelligence (analytic, creative, practical, verbal, mathematical, spatial, bodily-kinesthetic, musical, interpersonal, interpersonal, naturalist, or existentialist) does this individual has.
Professor Wooddro teaches an Introduction to Philosophy at the college. He loves to talk with students about the meaning of life and death and enjoys struggling with life's most challenging questions.
Answer:
verbal, IntrapersonalExplanation:
Remember, we are told that "Professor Wooddro teaches an Introduction to Philosophy at the college, and loves to talk about the meaning of life and death" which would require having verbal intelligence (the ability to understand and relate information using words).
Intrapersonal intelligence is also reflected by Professor Wooddro as we are told he "enjoys struggling with life's most challenging questions", which shows his knowledge of his own strengths or weaknesses.
Hello:) how to do 3?:)
Answer:
A
Explanation:
Please help!! Thank you<3 This isn't Physics its Sciene please help me :(
Answer:
The strong - arm team would win because they can excert more thrust on the rope.Explanation:
In this case, gravity is pulling down on them ( both teams ), the strong - arm team is excerting thrust by trying to pull the rope, and you've got the drag of the other team pulling back.
True or False. Friction can be reduced by lubricating or changing the shape of objects.
O True
OFalse
Answer: true
Explanation:
Answer:
true
Explanation:
Using lubricants such as oil or grease can reduce the friction between the surfaces
Name
4 items found
the first aid kit and
in
the lab.
Answer:
ummmmmwm whattt
Explanation:
wuhsnnsnsnsnms
Answer:
medicines
band-aids
aqua liquid
paracetamol
Explanation:
Extra items:
alcohol
cottons
bitadine
cotton buds
mask
