Answer:
for a)
Explanation:
(1.8 x 10^15)(11 x 10^3 m/s) = (5.98 x 10^24 + 1.8 x 10^15)vf
vf= (1.8 x 10^15)(11 x 10^3 m/s) / (5.98 x 10^24 + 1.8 x 10^15)
= 3.3×10−6 m/s
An electron (restricted to one dimension) is trapped between two rigid walls 1.40 nm apart. The electron's energy is approximately 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
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
things that affects the demand for electricity
21.Which of the following contain the molecules with the highest average speed?
C
L 나
G G
ico
cube
at -10°C
water
at roon
temperature
wood
at room
temperature
steam
at 110°C
A water molecule is made up of one oxygen and two hydrogen atoms. Why is water considered a pure substance?
Answer:
A mixture is when two or more substances combine physically together.
However, in water, two hydrogen atoms combine with one oxygen atom chemically, forming a new substance that has properties different from hydrogen alone or oxygen alone.
Explanation:
if a mass on a spring bobs up nad down completing 2 full cycles every section. WHat are the periouds and frequency of the mass
Answer:
This question is incomplete
Explanation:
This question is incomplete because of the absence of the time taken to complete one full cycle.
Frequency (f) will be calculated first as
f = N ÷ t
where N is the number of cycles and t is the time taken to complete one full cycle. The unit for frequency is Hertz (Hz).
To calculate the period, T, the formula below will be used
T = 1 ÷ f
The unit for period is secs
A batter hits a foul ball. The 0.140-kg baseball that was approaching him at 40.0 m/s leaves the bat at 30.0 m/s in a direction perpendicular to the line between the batter and the pitcher. What is the magnitude of the impulse delivered to the baseball?
A) 9.80 Ns
B) 3.50 Ns
C) 7.00 Ns
D) 5.60 Ns
E) 1.40 Ns
Answer:
The magnitude of the impulse delivered to the baseball is 7.0 Ns
Explanation:
Given;
mass of the foul ball, m = 0.14 kg
initial velocity, u = 40 m/s
final velocity, v = 30 m/s in perpendicular direction
Impulse is given as change in momentum;
initial momentum in horizontal direction, Pi = mu
Pi = 0.14 x 40 = 5.6 Ns
final momentum in perpendicular direction, Pf = mv
Pf = 0.14 x 30
Pf = 4.2 Ns
The resultant impulse is given by;
J² = 5.6² + 4.2²
J² = 49
J = √49
J = 7.0 Ns
Therefore, the magnitude of the impulse delivered to the baseball is 7.0 Ns
Find an expression for the center of mass of a solid hemisphere, given as the distance R from the center of the flat part of the hemisphere. Express your answer in terms of R. Express the coefficients using three significant figures.
Answer:
z_c = ⅜R
Explanation:
If we assume that the hemisphere has uniform density, we can express the centre of mass as;
z_c = (ρ/M)∫∫∫ z•dV
We know that density(ρ) = mass(M)/volume(V)
Thus, Vρ = M
And volume of hemisphere = 2πr³/3
Thus;
2Vρπr³/3 = M
So;
z_c = (ρ/(2Vρπr³/3))∫∫∫ z•dV
Where r = R in this case.
ρ will cancel out to give;
z_c = (3/(2πr³))∫∫∫_V (z•dV)
In spherical coordinates,
r is radius
Φ = angle between the point and the z − axis
θ = azimuthal angle
Therefore, the integral becomes what it is in the attached image.
I've completed the explanation as well in the attachment.
which property of potential energy distinguishes it from kinetic energy
Answer:
Shape and position
Explanation:
Hope this helps! :)
What is the momentum of 100 kg running at 4m/s north?
An old-fashioned tire swing exerts a force on the branch and a torque about the point where the branch meets the trunk. If you hang the swing closer to the trunk, this will ____ the force and ____ the torque.
Answer:
not change, decrease
Explanation:
Torque refers to the measure of the force that enables an object to rotate about an axis.
An old-fashioned tire swing exerts a force on the branch and a torque about the point where the branch meets the trunk. If you hang the swing closer to the trunk, this will not change the force and decrease the torque.
A tire swing when old can have aa small force. An old-fashioned tire swing exerts a force on the branch and a torque about the point where the branch meets the trunk. If you hang the swing closer to the trunk, this will not change, the force and decrease the torque.
It is stated that when the net force and the net torque are zero, the block is in static equilibrium.IT also state that when the net force is zero, but the net torque is not zero, the object is will not be in static equilibrium
For one too be able to change angular momentum, a torque must act on it over some timeframe.
Learn more from
https://brainly.com/question/22498107
Which action would decrease the strength of attraction between a magnet and an iron object
A. Moving the magnet farther away from the iron object
B. Moving the iron object closer to the magnet
C. Decreasing the number of electrons on the magnet
D. Increasing the number of electrons on the magnet
Answer:
a. moving the magnet farther away and an iron object.
Explanation:
Answer:A
Explanation:
A p e x
Full moon is located______
a. farthest from the Sun
b. at a 90 degree angle with the Sun and Earth
c. closest to the Sun
Answer:
Im going to take an educated guess and say its B.
Explanation:
A Full moon is located farthest from the Sun. Thus, the correct option for this question is A.
What is a Full moon?A full moon may be defined as one of the types of lunar phases when the Moon significantly appears fully illuminated from Earth's perspective. This event typically occurred when Earth is located between the Sun and the Moon.
When the earth is located between the sum and the moon, it is the time when the moon is located farthest from the sun. And it directs to an event of a full moon. The average time duration of the full moon and the repetition of the same phase normally requires 29.53 days.
Therefore, the Full moon is located farthest from the Sun. Thus, the correct option for this question is A.
To learn more about the Full moon, refer to the link:
https://brainly.com/question/15032553
#SPJ2
If you push a heavy box at rest, you must exert some force before it begins to move. Once its moving, you don’t have to as much force. Which of Newton’s three laws explains this?
Answer:
momentum does
Explanation:
Rita wants to make some toast for breakfast, which she knows involves a chemical change to the bread.
She puts a slice of bread in the toaster, but, after 10 minutes, she notices that the sides of the bread are
black. What caused this chemical change to go too far?
A. an increase in temperature
B. a decrease in temperature
C. the size of the bread
D. the type of bread
Answer:
A
Explanation:
The toaster was too high so its the increase in eat
Which sequence shows electromagnetic waves arranged in a decreasing order of their wavelengths?
Answer: Gamma rays, x-rays, ultraviolet rays, visible light, and infrared rays.
Answer:
C) radio → infrared → ultraviolet → gamma
Explanation:
It Increases left to right therefore it decreases right to left
How long would it take a 500. W electric motor to do 15010 J of work?
b. Interpret Data Solution A has a pH of 1.6.
Solution B has a pH of 4. Which solution
has a greater concentration of hydrogen
ions? Explain.
Answer:
Solution A has a pH of 6 and solution B has a pH of 8. Which of the following is true regarding the concentration of hydrogen ions in each solution? A) A has 100 times greater H+ concentration than B. B) B has 100 times greater H+ concentration than A. C) A has 7/9 of the H+ concentration of B. D) A has 9/7 of the H+ concentration of B. E) none of these
Explanation:
Hey im super sorry if i get this wrong :)
As the rate of radioactive decay becomes smaller half life become...
A thin spherical shell has a radius of 0.70 m. An applied torque of 860 N m gives the shell an angular acceleration of 4.70 rad/s2 about an axis through the center of the shell. What is the rotational inertia of the shell about the axis of rotation
Answer:
[tex]I=182.97\ kg-m^2[/tex]
Explanation:
Given that,
Radius of a spherical shell, r = 0.7 m
Torque acting on the shell, [tex]\tau=860\ N[/tex]
Angular acceleration of the shell, [tex]\alpha =4.7\ m/s^2[/tex]
We need to find the rotational inertia of the shell about the axis of rotation. The relation between the torque and the angular acceleration is given by :
[tex]\tau=I\alpha[/tex]
I is the rotational inertia of the shell
[tex]I=\dfrac{\tau}{\alpha }\\\\I=\dfrac{860}{4.7}\\\\I=182.97\ kg-m^2[/tex]
So, the rotational inertia of the shell is [tex]182.97\ kg-m^2[/tex].
A horizontal force of 100 N is applied to move a 50-kg cart (initially at rest) across a 10 m level surface. What is the final kinetic energy of the cart?
The net force on the cart is 100 N in the direction of its motion, so by Newton's second law we can find the acceleration a applied to it:
100 N = (50 kg) a
a = (100 N) / (50 kg)
a = 2 m/s²
The cart starts at rest and travels a distance of 10 m, so that its final velocity v satisfies
v ² - 0² = 2 (2 m/s²) (10 m)
v ²= 40 m²/s²
and so the cart ends up with kinetic energy
KE = 1/2 m v ² = 1/2 (50 kg) (40 m²/s²) = 1000 J
Can someone please help me with this problem. I’ve tried but I can’t seem to figure it out.
find the angle of projection at which the horizontal range is twice the maximum height of a projectile.
Answer:
Explanation:
We’re are we dining it
How many bonds can antimony form?
Answer:
An antimony can form 3 bonds
Let me know if this helps
Thanks!
:)
Explanation:
asheed and Sofia are riding a merry-go-round that is spinning steadily (uniform circular motion). Sofia is twice as far from the axis as is Rasheed. Sophia's acceleration is _________ that of Rasheed. *
Answer:
The same as
Explanation:
First of all, they are in a merry go round, which is a circular one. And thus, we would be dealing with circular motions.
The angular velocity of a merry go round, in this instance, is given by
w = Δ/Δt
The formula has nothing whatsoever to do with distance, and as such, both Rasheed and Sofia would have the same angular velocity.
Transferring this further, the angular acceleration is given as
α = Δw/Δt
Remember I said the velocity has nothing to do with distance, well, so does the acceleration as we can see from the formula stated. And therefore, both Rasheed and Sofia would have the same angular acceleration
At 96° F the saturation density of air is 0.04 kg/m3. If the weather report says the relative humidity is 90 % when the temperature is 96°F, the humidity is
Answer:
The value is [tex]H = 0.036 \ kg/m^3[/tex]
Explanation:
From the question we are told that
The saturation density of air is [tex]\rho = 0.04 \ kg/m^3[/tex]
The temperature for this saturation density to occur [tex]T_s = 96^o F[/tex]
The relative humidity at this temperature is [tex]R_h = 90\% = 0.90[/tex]
Generally the relative humidity is mathematically represented as
[tex]R_H = \frac{H}{\rho}[/tex]
Here H represents humidity
=> [tex]0.90 = \frac{H}{0.04}[/tex]
=> [tex]H = 0.90 * 0.04[/tex]
=> [tex]H = 0.036 \ kg/m^3[/tex]
If a car traveled 50 meters in 2 seconds, what will the velocity be? (Write the answer with a number, on decimal if needed, then a space and the units, for example 5.7 m/s)
Answer:
The answer is 25 m/sExplanation:
The velocity of the car can be found by using the formula
[tex]v = \frac{d}{t} \\ [/tex]
d is the distance
t is the time taken
From the question we have
[tex]v = \frac{50}{2} \\ [/tex]
We have the final answer as
25 m/sHope this helps you
A certain star has a temperature twice that of the Sun and a luminosity 70 times greater than the solar value. What is its radius, in solar units
Answer:
[tex] R = 2.1R_{\bigodot} [/tex]
Explanation:
The radius (R) is related to temperature (T) and the luminosity (L) as follows:
[tex] L = T^{4} \times R^{2} [/tex]
By solving the above equation for R we have:
[tex] R = \frac{\sqrt{L}}{T^{2}} [/tex]
With [tex]L = 70L_{\bigodot}[/tex] and [tex]T = 2T_{\bigodot}[/tex] we have:
[tex] R = \frac{\sqrt{70L_{\bigodot}}}{(2T_{\bigodot})^{2}} [/tex]
[tex] R = \frac{\sqrt{70}}{(2)^{2}} [/tex]
[tex] R = 2.1R_{\bigodot} [/tex]
Therefore, the radius is 2.1 times that of the Sun.
I hope it helps you!
If you cannot exert enough force to loosen a bolt with a wrench, which of the following should you do?
Question 5 options:
1.) Tie a rope to the end of the wrench and pull on the rope.
2.) Use a wrench with a longer handle.
3.) You should exert a force on the wrench closer to the bolt.
4.) Use a wrench with a shorter handle.
Answer:
2.) Use a wrench with a longer handle.
Explanation:
It is suggested to use a wrench with longer handle if you cannot exert enough force to loosen a bolt with a wrench.
In doing this work, the torque which is the force that can turn the screw is not enough;
Torque = force x distance
If we increase the distance or the length of the handle, we can generate more torque to overcome the force needed.
Explain what forces act on human body in equilibrium.
An artery with cross sectional area of 1 cm2 branches into 20 smaller arteries each with 0.5 cm2 cross sectional area. If the velocity of blood in the thicker artery is v, what is the velocity of the blood in the thinner arteries
Answer:
The velocity of the blood in the thinner arteries is 0.1 times that of the thicker artery.
Explanation:
To find the velocity of the blood we need to use the continuity equation:
[tex] n_{1}A_{1}v_{1} = n_{2}A_{2}v_{2} [/tex] (1)
Where:
n: is the number of branches
A: is the cross-sectional area
v: is the velocity
For artery 1, we have:
n₁ = 1, A₁ = 1 cm², v₁ = v
For the 20 arteries (2), we have:
n₂ = 20, A₂ = 0.5 cm², v₂ =?
By using equation (1):
[tex] n_{1}A_{1}v_{1} = n_{2}A_{2}v_{2} [/tex]
[tex] 1 cm^{2}*v = 20*0.5 cm^{2}*v_{2} [/tex]
[tex] v_{2} = \frac{1 cm^{2}*v}{20*0.5 cm^{2}} = \frac{v}{10} = 0.1v [/tex]
Therefore, the velocity of the blood in the thinner arteries is 0.1 times that of the thicker artery.
I hope it helps you!
