1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
jeka94
3 years ago
11

An electron (restricted to one dimension) is trapped between two rigid walls 1.40 nm apart. The electron's energy is approximate

ly 19 eV. (a) What is the quantum number n for the energy state that the electron occupies? (b) Based on the quantum number you found in part (a), calculate a more precise value for the electron's energy in eV), expressed to at least three significant figures. (Use any physical constants or unit conversions to at least four significant figures in your calculations.) _________ eV
Physics
1 answer:
Bumek [7]3 years ago
3 0

Answer:

a)    n = 9.9       b)      E₁₀ = 19.25 eV

Explanation:

Solving the Scrodinger equation for the electronegative box we get

         Eₙ = (h² / 8m L²2) n²

where l is the distance L = 1.40 nm = 1.40 10⁻⁹ m and n the quantum number

 In this case En = 19 eV let us reduce to the SI system

          En = 19 eV (1.6 10⁻¹⁹ J / 1 eV) = 30.4 10⁻¹⁹ J

          n = √ (In 8 m L² / h²)

let's calculate

          n = √ (8  9.1 10⁻³¹ (1.4 10⁻⁹)²  30.4 10⁻¹⁹ / (6.63 10⁻³⁴)²

          n = √ (98)            n = 9.9

since n must be an integer, we approximate them to 10

b) We substitute for the calculation of energy

        In = (h² / 8mL2² n²

        In = (6.63 10⁻³⁴) 2 / (8 9.1 10⁻³¹  (1.4 10⁻⁹)² 10²

        E₁₀ = 3.08 10⁻¹⁸ J

we reduce eV

      E₁₀ = 3.08 10⁻¹⁸ j (1ev / 1.6 10⁻¹⁹J)

      E₁₀ = 1.925 101 eV

      E₁₀ = 19.25 eV

the result with significant figures is

        E₁₀ = 19.25 eV

You might be interested in
g A change in the initial _____ of a projectile changes the range and maximum height of the projectile.​
docker41 [41]

Answer:

Velocity.

Explanation:

Projectile motion is characterized as the motion that an object undergoes when it is thrown into the air and it is only exposed to acceleration due to gravity.

As per the question, 'any change in the initial velocity of the projectile(object having gravity as the only force) would lead to a change in the range as well as the maximum height of the projectile.' To illustrate numerically:

Horizontal range: As per expression:

R= (u^{2}*sin2θ)/g

the range depending on the square of the initial velocity.

Maximum height: As per expression:

H= (u^{2} * sin^{2}θ )/2g

the maximum distance also depends upon square of the initial velocity.

​

​

​

7 0
3 years ago
Describe the climate, landforms,and existing plant and animal life during the cretaceous period
Fiesta28 [93]
The climate<span> was generally warmer and more humid than today, probably because of very active volcanism associated with unusually high rates of seafloor spreading. 
</span><span>The first placental mammals appeared at the beginning of the Cretaceous. The Cretaceous saw the rise and extinction of the toothed birds, Hesperornis and Ichthyornis. The earliest fossils of birds resembling loons, grebes, cormorants, pelicans, flamingos, ibises, rails, and sandpipers were from the Cretaceous.</span>
8 0
3 years ago
Read 2 more answers
Match these items.
Nitella [24]

Explanation :

(1) Involuntary muscles are the muscles that are not controlled by our will.

(2) Tendons are the connective tissues that join the muscle to bones. Tendons are tissues that have fibers.

(3) Cardiac muscle is also involuntary muscles. For example heart muscle. It shows contraction and relaxation throughout life.

(4) Voluntary muscle is the muscles that are not controlled by our will.  

(5) Biceps are the arm muscles.

Hence, this the required explanation as per options.

4 0
3 years ago
If the force applied to an object is not greater than the starting friction, what will happen to the object?
bonufazy [111]

Answer:

Explanation:

the object will not move as the force exerted is not sufficient enough to overcome its force of friction

3 0
3 years ago
Read 2 more answers
arzan, who weighs 700 N, swings from a cliff at the end of a convenient vine thatis 20 m long. From the top of the cliff to the
vekshin1

Answer:

= 7.07 m

Explanation:

The Tarzan reaches bottom of swing after descending 2.5 m,

change in his potential energy equals his kinetic energy at bottom of swing

m g h = (1/2) m v²   ,  

hence speed v of Tarzan at bottom of swing is given as  

v = ( 2 g h )1/2

= ( 2 × 9.8 × 2.5 )1/2

= 7 m/s

At the bottom of swing, if the vine breaks, then he is moving with horizontal velocity 7 m/s in gravitational field.  

If vertical distance from ground to bottom of swing is 5 m, then time t for Tarzan to reach ground is given by

S = (1/2)g t2 or   t = (2S/g)1/2

= ( 2 × 5 / 9.8 )1/2

= 1.01 s

Horizontal distance traveled by Tarzan = 1.01 × 7

= 7.07 m

7 0
3 years ago
Other questions:
  • You jump off a platform 134 m above the Neuse River. After you have free-fallen for the first 40 m, the bungee cord attached to
    10·2 answers
  • Jumps at 8 m/s at a 30 degree angle above the horizontal. how long was she in the air?
    12·1 answer
  • A node is a point on a standing wave that has no displacement from the rest position. at the nodes, _____.
    15·2 answers
  • How many planets are there?
    12·2 answers
  • What is a living organism? Give a few examples.
    15·1 answer
  • 6. A car travels a distance of 10 miles in 2 minutes towards 695 north east. 3 points
    15·1 answer
  • If a big person and a small person run up the stairs at the same time who has more force
    15·2 answers
  • Find the relationship between 'g' and 'G'​
    10·2 answers
  • Which of these statements best describes the relationship between elements, compounds, and pure substances? (2 points)
    13·1 answer
  • Two wires A and B with circular cross sections are made of the same metal and have equal lengths, but the resistance of wire A i
    15·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!