The Hydrogen Spectrum
When a low-pressure gas of hydrogen atoms is placed in a tube and a large voltage is applied to the end of the tube, the atoms will emit electromagnetic radiation and visible light can be observed. If this light passes through a diffraction grating, the resulting spectrum appears as a pattern of four isolated, sharp parallel lines, called spectral lines. Each spectral line corresponds to one specific wavelength that is present in the light emitted by the source. Such a discrete spectrum is referred to as a line spectrum
By the early 19th century, it was found that discrete spectra were produced by every chemical element in its gaseous state. Even though these spectra were found to share the common feature of appearing as a set of isolated lines, it was observed that each element produces its own unique pattern of lines. This indicated that the light emitted by each element contains a specific set of wavelengths that is characteristic of that element.
The first quantitative description of the hydrogen spectrum was given by Johann Balmer, a Swiss school teacher, in 1885, By trial and error, he found that the correct wavelength λ of each line observed in the hydrogen spectrum was given by
1/λ = R ( 1/2^2-1/n^2)
where R is a constant, later called the Rydberg constant, and n may have the integer values 3, 4, 5, If λ is in meters, the numerical value of the Rydberg constant (determined from measurements of wavelengths) s R= 1.097x10^7 m-1
Balmer knew only the four lines in the visible spectrum of hydrogen. Thus, the original formula was written for a limited set of values of T. However, as more techniques to detect other regions of the spectrum were developed, it became clear that Balmer's formula was valid for all values of n. The entire series of spectral lines predicted by Balmers formula is now referred to as the Balmer series
Part A) What is the wavelength of the line corresponding to n =4 in the Balmer series? Express your answer in nanometers to three significant figures .
Part B) What is the wavelength of the line corresponding to n =5 in the Balmer series?

Answers

Answer 1

Answer:

a)   λ = 4.862 10⁻⁷ m,  b)  λ = 4.341 10⁻⁷ m

Explanation:

The spectrum of hydrogen can be described by the expression

         [tex]\frac{1}{\lambda} = R_H ( \frac{1}{n_o^2} - \frac{1}{n^2} ) \ \ \ \ n>n_o[/tex]

in the case of the initial state n = 2 this series is the Balmer series

a) Find the wavelength for n = 4

       

let's calculate

          [tex]\frac{1}{ \lambda}[/tex] = 1,097 10⁷ ([tex]\frac{1}{2^2} - \frac{1}{4^2}[/tex])

          \frac{1}{ \lambda} = 1.097 10⁷ 0.1875 = 0.2056 10⁷

           λ = 4.862 10⁻⁷ m

b) n = 5

           

     \frac{1}{ \lambda} = 1,097 10⁷ ([tex]\frac{1}{2^2} - \frac{1}{5^2}[/tex])

     \frac{1}{ \lambda} = 1.097 10⁷ 0.21 = 0.23037 10⁷

      λ = 4.341 10⁻⁷ m


Related Questions

What is another example of convection

Answers

radiator. A radiator puts warm air out at the top and draws in cooler air at the bottom. steaming cup of hot tea - The steam you see when drinking a cup of hot tea indicates that heat is being transferred into the air. ice melting/Ice melts because heat moves to the ice from the air

Answer:

boiling water - When water heats, the heat from the burner is transferred to the container, heating the water at the bottom. This hot water rises, creating a circular motion, as colder water descends to replace it.

. A circular wire loop 40 cm in diameter has 100 Ohm resistance and lies in a horizontal plane. A uniform magnetic field points vertically downward, and in 25 ms it increases from 5 mT to 55 mT. Find the magnetic flux through the loop at (a) the beginning and (b) the end of 25 ms period. (c) What is the loop current during this time

Answers

Answer:

(a) 6.283 Wb (b) 69.11 Wb (c) I = 0.628 A

Explanation:

Given that,

The diameter of the loop, d = 40 cm

Radius, r = 20 cm

Initial magnetic field, B = 5 mT

Final magnetic field, B' = 55 mT

Initial magnetic flux,

[tex]\phi_i=BA\\\\=5\times 10^{-3}\times \pi \times 20^2\\\\=6.283\ Wb[/tex]

Final magnetic flux,

[tex]\phi_f=B'A\\\\=55\times 10^{-3}\times \pi \times 20^2\\\\=69.11\ Wb[/tex]

Due to change in magnetic field an emf will be generated in the loop. It is given by :

[tex]\epsilon=-\dfrac{d\phi}{dt}\\\\=\phi_f-\phi_i\\\\=69.11-6.283\\\\=62.827\ V[/tex]

Let I be the current in the loop. We can find it using Ohm's law such that,

[tex]\epsilon=IR\\\\I=\dfrac{\epsilon}{R}\\\\I=\dfrac{62.827}{100}\\\\=0.628\ A[/tex]

Hence, this is the required solution.

So the the greater the height, the
farther something can fall, the greater
the potential energy.
True
False

Answers

The heavier the object and the higher it is above the ground, the more gravitational potential energy it holds.

Imagine that the satellite described in the problem introduction is used to transmit television signals. You have a satellite TV reciever consisting of a circular dish of radius RRR which focuses the electromagnetic energy incident from the satellite onto a receiver which has a surface area of 5 cm2cm2. How large does the radius RRR of the dish have to be to achieve an electric field vector amplitude of 0.1 mV/mmV/m at the receiver

Answers

Answer:

R₁ = 0.126 m

Explanation:

Let's use the definition of intensity which is the power per unit area

          I = P / A

the generated power is constant

          P = I A

power is

         P = E / t

if we perform the calculations for a given time, the wave energy is

        E = q V

we substitute

        P = [tex]\frac{q V\ A}{t}[/tex]

we can write this equation for two points, point 1 the antenna and point 2 the receiver

         V₁A₁ = V₂A₂

          A₁ = [tex]\frac{V_2}{V_1} \ A_2[/tex]

          A₁ = 0.1 10⁻³  5 10⁻⁴ /V₁

          A₁ = 5 10⁻⁸ /V₁

In general, the electric field on the antenna is very small on the order of micro volts, suppose V₁ = 1 10⁻⁶ V

           

let's calculate

          A₁ = 5 10⁻⁸ / 1 10⁻⁶

         A₁ = 5 10⁻² m²

the area of ​​a circle is

          A = π r²

we substitute

         π R1₁²= 5 10⁻²

         R₁ = [tex]\sqrt{ \frac{5 \ 10^{-2} }{\pi } }}[/tex]

         R₁ = 0.126 m

If a gas turned into a solid without going through the liquid state and how do you reverse it?

Answers

Answer:

put it in a volcano

Explanation:

Deposition is the phase transition in which gas transforms into solid without passing through the liquid phase. Deposition is a thermodynamic process. The reverse of deposition is sublimation and hence sometimes deposition is called desublimation.

I WILL REPORT YOU IF YOU ANSWER WITH LINK!!! WILL GIVE BRAINLIEST

You have two identical bowling balls that are 1.00 m apart as measured from their centers. There is an attractive force of gravity between them due to their mass. When a net charge of +0.40 nC is placed on each bowling ball, the force exerted by the electrostatic forces exactly balances the force of gravity on the bowling balls resulting in a net charge of zero. The formula for the electrostatic force is similar to the formula for the gravitational force. There is a constant that is multiplied by the magnitude of each of the two charges and divided by the square of the distance between them. What two conclusions can you draw from this information?


CHOOSE 2 ANSWERS

Answers

Answer:

I think is is

Explanation:

B and C why because i have a gut feeling

1. The block shown below is being putled to the right on a horizontal table,
Which labeled vectors represent all the forces acting on the block?

Answers

Answer:

E

Explanation:

As you look out of your dorm window, a flower pot suddenly falls past. The pot is visible for a time t, and the vertical length of your window is Lw. Take down to be the positive direction, so that downward velocities are positive and the acceleration due to gravity is the positive quantity g. Assume that the flower pot was dropped by someone on the floor above you (rather than thrown downward). If the bottom of your window is a height hb above the ground, what is the velocity vground of the pot as it hits the ground? You may introduce the new variable vb, the speed at the bottom of the window, defined by
vb = Lwt + gt2.

Answers

Answer:

[tex]\mathbf{v_{ground} = \sqrt{{v^2+2ghb}}}[/tex]

Explanation:

From the information given:

The avg. velocity post the window is;

[tex]v_{avg} = \dfrac{L_w}{t}[/tex]

[tex]v_b[/tex] = velocity located at the top of the window

[tex]v_b[/tex] = velocity situated at the bottom of the window  

Using the equation of kinematics:

[tex]v_b = v_t + gt[/tex]

Hence,

[tex]v_t = v_b - gt[/tex]

To determine the average velocity as follows:

[tex]v_{avg} = \dfrac{1}{2} (v_t + v_b)\dfrac{L_w}{t}= \dfrac{1}{2}(v_b - gt +v_b) \\ \\\dfrac{L_w}{t} = v_b - \dfrac{1}{2}gt \\ \\ v_b = \dfrac{L_w}{t }+ \dfrac{1}{2} gt\\ \\ = \dfrac{1}{t} \Bigg(L_w + \dfrac{1}{2}gt^2 \Bigg) \\ \\[/tex]

where;

[tex]v_b[/tex] = velocity gained when fallen through the height h.

Similarly, using the equation of kinematics, we have;

[tex]v_b^2 = 2gh \\ \\h = \dfrac{v_b^2}{2g}[/tex]

[tex]\implies \dfrac{(L_w + \dfrac{1}{2} gt^2_^2}{2gt^2}[/tex]

Thus, the velocity at the ground is;

[tex]v^2_{grround} = v_b^2 + 2ghb[/tex]

[tex]\mathbf{v_{ground} = \sqrt{{v^2+2ghb}}}[/tex]

molecules , like hormones , are made up of which of the following

A. cells
B. Atoms
C. Tissues
D. Organs

Answers

Answer:

atoms

Explanation:

Hormones are derived from amino acids or lipids. Amine hormones originate from the amino acids tryptophan or tyrosine. Larger amino acid hormones include peptides and protein hormones. Steroid hormones are derived from cholesterol.

The answer is b atoms and can possibly b d

A small wooden block with mass 0.750 kg is suspended from the lower end of a light cord that is 1.40 m long. The block is initially at rest. A bullet with mass 0.0100 kg is fired at the block with a horizontal velocity v0. The bullet strikes the block and becomes embedded in it. After the collision the combined object swings on the end of the cord. When the block has risen a vertical height of 0.800 m, the tension in the cord is 5.00 N.

Required:
What was the initial speed v0 of the bullet?

Answers

Answer:

The initial speed of the bullet will be:

[tex]v_{ib}=331.36\: m/s[/tex]

Explanation:

Using the momentum conservation:

[tex]p_{i}=p_{f}[/tex]

[tex]m_{b}v_{ib}=Mv[/tex] (1)

Where:

M is the mass of the black plus the mass of the bulletv(ib) is the initial velocity of the bulletv is the velocity of the block with the bullet inside.

Using the conservation of energy:

[tex]\frac{1}{2}Mv^{2}=\frac{1}{2}Mv_{2}^{2}+Mgh [/tex] (2)

Where v(2) is the speed of the system at 0.8 m of vertical height.

Using the forces acting on the system we can find v(2).

The forces can be equal to the centripetal force:

[tex]T-Mg*sin(\alpha)=M\frac{v_{2}^{2}}{L}[/tex]            

α is the angle of T with respect to the horizontal, here α = 25.4°  

So, v(2) will be:

[tex]T-Mg*sin(\alpha)=M\frac{v_{2}^{2}}{L}[/tex]  

[tex]\frac{L}{M}(T-Mg*sin(\alpha))=v_{2}^{2}[/tex]  

[tex]\frac{1.4}{0.76}(5-0.76*9.81*sin(25.4))=v_{2}^{2}[/tex]  

[tex]v_{2}=1.82 \: m/s[/tex]

Using this value on equation (2) we will find v.

[tex]v^{2}=v_{2}^{2}+2gh [/tex]

[tex]v^{2}=1.82^{2}+2(9.81)(0.8) [/tex]

[tex]v=4.36\: m/s [/tex]

And finally using equation (1) we can find the initial speed of the bullet.

[tex]m_{b}v_{ib}=Mv[/tex]

[tex]0.01*v_{ib}=0.76*4.36[/tex]

[tex]v_{ib}=331.36\: m/s[/tex]

I hope it helps you!

Electron spin: Radio astronomers can detect clouds of hydrogen too cool to radiate optical wavelengths of light by means of the 21 cm spectral line corresponding with the flipping of the electron in a hydrogen atom from having its spin parallel to the proton spin to having it antiparallel. From this wavelength, and thus E between states, find the magnetic field experienced by the electron in a hydrogen atom

Answers

Answer:

the magnetic field experienced by the electron is 0.0511 T

Explanation:

Given the data in the question;

Wavelength λ = 21 cm = 0.21 m

we know that Bohr magneton μ[tex]_B[/tex] is 9.27 × 10⁻²⁴ J/T

Plank's constant h is 6.626 × 10⁻³⁴ J.s

speed of light c = 3 × 10⁸ m/s

protein spin causes magnetic field in hydrogen atom.

so

Initial potential energy = -μ[tex]_B[/tex]B × cos0°

= -μ[tex]_B[/tex]B × 1

= -μ[tex]_B[/tex]B

Final potential energy = -μ[tex]_B[/tex]B × cos180°

= -μ[tex]_B[/tex]B × -1

= μ[tex]_B[/tex]B

so change in energy will be;

ΔE = μ[tex]_B[/tex]B - ( -μ[tex]_B[/tex]B )

ΔE = 2μ[tex]_B[/tex]B

now, difference in energy levels will be;

ΔE = hc/λ

2μ[tex]_B[/tex]B = hc/λ

2μ[tex]_B[/tex]Bλ = hc

B = hc /  2μ[tex]_B[/tex]λ

so we substitute

B = [(6.626 × 10⁻³⁴) × (3 × 10⁸)]  /  [2(9.27 × 10⁻²⁴) × 0.21 ]

B = [ 1.9878 × 10⁻²⁵ ]  /  [ 3.8934 × 10⁻²⁴ ]

B = 510556326.09

B = 0.0511 T

Therefore, the magnetic field experienced by the electron is 0.0511 T

form
bonds with each other.
There are many kinds of mixtures. Some mixtures are
chunky like a mixture of peanuts and raisins. These
mixtures are called
I
mixtures.

Answers

Answer:

Homogeneous mixtures

Explanation:

I think so because homogeneous means mixed mixtures

Radio waves travel at the speed of light. What is the wavelength of a radio signal with a frequency of 9.45 x 10^7 Hz?

Answers

The wavelength of this radio signal is equal to 3.18 meters.

Given the following data:

Frequency = [tex]9.45 \times10^7[/tex] Hz.Speed of light = [tex]3 \times 10^8[/tex] m/s.

What is wavelength?

Wavelength can be defined as the distance between two (2) successive crests (troughs) of a wave.

How to calculate wavelength.

Mathematically, the wavelength of a wave is given by this formula:

[tex]\lambda = \frac{V}{F}[/tex]

Where:

F is the frequency of a wave.V is the speed of a sound wave.[tex]\lambda[/tex] is the wavelength of a sound wave.

Substituting the given parameters into the formula, we have;

[tex]\lambda = \frac{3 \times 10^8}{9.45 \times10^7}[/tex]

Wavelength = 3.18 meters.

Find more information on waves here: brainly.com/question/23460034

The wavelength of the radio signal travel at speed of light is 3.17m.

Given the data in the question;

Frequency of the radio wave; [tex]f = 9.45 * 10^{7}Hz = 9.45 * 10^{7} s^{-1}[/tex]Wavelength of a radio signal; [tex]\lambda = \ ?[/tex]

Wavelength

Wavelength the spatial period of a periodic wave. That is to say, when the shapes of waves are Wavelength , the distance over which they are repeated is called wavelength. Wavelength  is expressed as;

[tex]\lambda = \frac{v}{f}[/tex]

Where [tex]\lambda[/tex] is wavelength, f is the frequency of the wave and c is the velocity or speed of light ( [tex]c = 3*10^8m/s[/tex] )

We substitute our values into the expression above.

[tex]\lambda = \frac{c}{ f}\\ \\\lambda = \frac{3*10^8m/s}{9.45*10^7s^{-1}} \\\\\lambda = \frac{3*10^8ms/s}{9.45*10^7}\\\\\lambda = 3.17m[/tex]

Therefore, the wavelength of the radio signal travel at speed of light is 3.17m.

Learn more about wavelength: brainly.com/question/16776907

6. Applying Explain how scientists see what early galaxies looked like..

Answers

Answer:  The younger elliptical and lenticular galaxies had results similar to spiral galaxies like the Milky Way. The researchers found that the older galaxies have a larger fraction of low-mass stars than their younger counterparts.

Explanation:

which process of the method a neutral object obtains an. electrical charge

Answers

Induction is a method for a neutral object to gain a charge. It requires bringing a charged object close to the neutral object.

The Image shows a magnetic field around the poles of a magnet. Identify the areas where the magnetic force is the strongest.
N

Answers

Answer:

strongest are at the points of the north pole and the south pole, specifically between the red box and the letter of each pole.

Explanation:

The lines of magnetic force are drawn so that the density of lines is proportional to the intensity of the magnetic field.

Therefore, the sections where the magnetic field is strongest are at the points of the north pole and the south pole, specifically between the red box and the letter of each pole.

large roll of fabric
Costume Rendering

Scissors

Pattern

Bolt

Answers

Answer:

Do we have to choose out of those three?

Explanation:

A particle of ink in a ink-jet printer carries a charge of -8x 10^-13 C and is deflected onto paper force of 3.2x10^-4. Find the strength of the electric field

Answers

Beef and cheddar is your answer

Calculate the force of an object that has a mass of 10kg and an acceleration of 4m/s²
A-40N
B-8N
C-2.5N
D-0.4N

Answers

The answer is A-40N.

The volumes of two bodies are measured to be

V₁ = (10.2 ± 0.02) cm³ and V₂ = (6.4 ± 0.01) cm³. Calculate sum and difference in

volumes with error limits.​

Answers

Answer:

sum of volumes = (16.6 ± 0.03) cm³

and difference of volumes = (3.8 ± 0.03) cm³

Explanation:

Here,

V₁ = (10.2 ± 0.02) cm³ and V₂ = (6.4 ± 0.01) cm³.

Now,

∆V = ± (∆V₁ + ∆V₂)

= ± (0.02 + 0.01) cm³

= ± 0.03 cm³

V₁ + V₂ = (10.2 + 6.4) cm³ = 16.6 cm³ and

V₁ - V₂ = (10.2 - 6.4) cm³ = 3.8 cm³

Thus, sum of volumes = (16.6 ± 0.03) cm³

and difference of volumes = (3.8 ± 0.03) cm³

-TheUnknownScientist

Answer:

I hope it's helpful .............

Why did the “yielders” conform in Asch’s experiment?

Answers

Answer:

Asch's experiment showed that about 75% of people were "yielders" who conformed and 25% were "independent" who didn't conform. Asch concludes that people ignored reality and gave an incorrect answer in order to follow the rest of the group.

5. What is the period of a vertical mass-spring system that has an amplitude of
71.3 cm and maximum speed of 7.02 m/s? The spring constant is 12.07 N/m.

Answers

The period of the vertical mass-spring is 0.64 s.

The given parameters:Amplitude of the spring, A = 71.3 cm Maximum speed of the spring, V = 7.02 m/sSpring constant, k = 12.07 N/m

The angular speed of the vertical mass-spring is calculated as follows;

[tex]V_{max} = A \omega\\\\\omega = \frac{V_{max}}{A} \\\\\omega = \frac{7.02}{0.713} \\\\\omega = 9.85 \ rad/s[/tex]

The period of the vertical mass-spring is calculated as follows;

[tex]f = \frac{\omega }{2\pi} \\\\T = \frac{1}{f} \\\\T = \frac{2 \pi}{\omega } \\\\T = \frac{2\pi }{9.85} \\\\T = 0.64 \ s[/tex]

Thus, the period of the vertical mass-spring is 0.64 s.

Learn more about period of oscillation here: https://brainly.com/question/20070798

Aliens from the planet Mars can have long or short antennas. The allele for a long antenna is DOMINANT, and the allele for a short antenna is RECESSIVE. Which of the following is the pair of alleles an alien would have to inherit to have a short antenna?

Recessive, dominant


Dominant, dominant


Recessive, recessive


Dominant, recessive

Answers

Answer:

Recessive, dominant

Explanation:

umm thats the answer

o reduce the drag coefficient and thus to improve the fuel efficiency, the frontal area of a car is to be reduced. Determine the amount of fuel and money saved per year as a result of reducing the frontal area from 18 to 14 ft2. Assume the car is driven 12,000 mi a year at an average speed of 55 mi/h. Take the density and price of gasoline to be 50 lbm/ft3 and $3.10/gal, respectively; the density of air to be 0.075 lbm/ft3, the heating value of gasoline to be 20,000 Btu/lbm; and the overall efficiency of the engine to be 30 percent. Take the drag coefficient as CD

Answers

Complete question

To reduce the drag coefficient and thus to improve the fuel efficiency, the frontal area of a car is to be reduced. Determine the amount of fuel and money saved per year as a result of reducing the frontal area from 18 to 14 ft2. Assume the car is driven 12,000 mi a year at an average speed of 55 mi/h. Take the density and price of gasoline to be 50 lbm/ft3 and $3.10/gal, respectively; the density of air to be 0.075 lbm/ft3, the heating value of gasoline to be 20,000 Btu/lbm; and the overall efficiency of the engine to be 30 percent. Take the drag coefficient as CD=0.3 for a passenger car.

Answer:

22.22%

$57

Explanation:

From the question we are told that

Initial area of frontal area [tex]a_1=18ft^2[/tex]

Final area of frontal area [tex]a_2=14ft^2[/tex]

Distance covered a year [tex]D=12000mile[/tex]

Average speed a year [tex]V_{avg}=55mile/h[/tex]

Density [tex]\rho=50 lbm/ft3[/tex]

Price [tex]P= $3.10/gal[/tex]

Density of air [tex]\rho_{air} 0.075 lbm/ft3[/tex]

Heating value of gasoline [tex]Q=20,000 Btu/lbm[/tex]

Efficiency [tex]\eta=30\%[/tex]

Drag coefficient [tex]CD=0.3[/tex]

[tex]\triangle A=18-14ft^2=4ft^2[/tex]

Generally the equation for drag force [tex]C_D[/tex] is mathematically given as

[tex]F_D=\frac{C_DAPV^2}{2}[/tex]

[tex]F_D=\frac{0.3*18*0.075*(80.685^2)*A}{2}[/tex]

[tex]F_D=73.24Alb[/tex]

where [tex]v=55mil/h*1.467=80.685ft/s[/tex]

Generally the equation for work done W is mathematically given as[tex]W=F_D*L[/tex]

where [tex]L=12000mile*5280[/tex]

[tex]L=63360000[/tex]

[tex]W=73.24A*63360000[/tex]

[tex]W=4.6*10^9A[/tex]

Generally the equation for overall efficiency [tex]\eta[/tex] is mathematically given as

where

[tex]W_{req}=required\ gasoline\ power\ efficiency[/tex]

[tex]\eta=\frac{W}{W_{req}}[/tex]

[tex]W_{req}=\frac{W}{\eta}[/tex]

[tex]W_{req}=\frac{4.6*10^9}{0.3}[/tex]

[tex]W_{req}=1.55*10^{10}A[/tex]

Generally the equation for reduction fee with change in frontal area [tex]\triangle M[/tex] is mathematically given as

[tex]\triangle M =\triangle Vgasoline*cost[/tex]

Where

[tex]\triangle Vgasoline= volume\ reduction\ of\ gasoline[/tex]

[tex]\triangle Vgasoline=\frac{E_{req}}{H*P}[/tex]

[tex]\triangle Vgasoline=\frac{1.55*10^{10}A}{20000*778.169*32.2*50}[/tex]

if

[tex]20000btu/ibm=20000*778.169*32.2(1bm.ft^2/s)[/tex]

[tex]\triangle Vgasoline=\frac{1.55*10^{10}A}{20000*778.169*32.2*50}[/tex]

[tex]\triangle Vgasoline=0.61859A[/tex]

Therefore

[tex]\triangle M =0.61859A*3.10[/tex]

if [tex]1ft^2=7.48gal[/tex]

[tex]\triangle M =0.61859(4)*3.10*7.48[/tex]

[tex]\triangle M = \$ 57.671[/tex]

Generally the equation for reduction of fuel [tex]F_r[/tex]is mathematically given as

[tex]F_r=\frac{\triangle A}{\triangle i}*100[/tex]

where

[tex]\triangle i=18ft^2[/tex]

[tex]F_r=\frac{4}{18}*100[/tex]

Fuel reduction price by reducing front area is 22.22%

Money saved per year is $57

Question /
Which object is shown below?
A. Convex mirror
B. Convex lens
C. Concave lens
D. Concave mirror
SLIDNAT

Answers

The answer is A or D

A pendulum is constructed from a heavy metal rod and a metal disk, both of uniform mass density. The center of the disk is bolted to one end of the rod, and the pendulum hangs from the other end of the rod. The rod has a mass of =1.0 kg and a length of =49.8 cm. The disk has a mass of =4.0 kg and a radius of =24.9 cm. The acceleration due to gravity is =9.8 m/s2.
The pendulum is held with the rod horizontal and then released. What is the magnitude of its angular acceleration at the moment of release?

Answers

The magnitude of the angular acceleration of the pendulum at the moment of release is; α = 18.45 rad/s²

We are given;

Mass of rod; m = 1 kg

Length of rod; L = 49.8 cm = 0.498 m

Mass of Disk; M = 4 kg

Radius of disk; r = 24.9 cm = 0.249 m

Let us first calculate the torque acting from the formula;

τ = mg(L/2) + MgL

Thus;

τ = (1 × 9.8 × (0.498/2)) + (4 × 9.8 × 0.498)

τ = 21.96 N.m

Using parallel axis theorem, we can find the moment of inertia about the given axis as;

I = (mL²/3) + ½MR² + ML²

Plugging in the relevant values gives;

I = (1 * 0.498²/3) + ½(4 * 0.249²) + (4 * 0.498²)

I = 1.19 kg.m²

The angular acceleration is given by the formula;

α = I/τ

α = 21.96/1.19

α = 18.45 rad/s²

Read more at; https://brainly.com/question/23321366

During a soccer game, a player grabs and holds an opponent's shirt outside of the penalty box. After the foul is called, what kick is awarded to put the ball back into play?

a
Penalty Kick
b
Indirect Free Kick
c
Kickoff
d
Direct Free Kick

Answers

D. Direct Free Kick

Types of RM radiation that make up the electromagnetic spectrum are microwaves, infrared light, ultraviolet light, X-rays, and gamma rays.

True
False

Answers

Answer:

True

Explanation:

The electromagnetic spectrum can be regarded as term that give description of range of light that are in existence, and this range from radio waves up to gamma rays. It can be explained as

range of frequencies that electromagnetic radiation takes with thier respective wavelengths as well as photon energies

The Types of electromagnetic radiation that make up the electromagnetic spectrum are

✓ microwaves

✓ infrared light

✓ ultraviolet light

✓X-rays,

✓gamma rays.

PLEASE HELPPPPPP <333​

Answers

Answer:

Explanation:

The answer is c. I am very sure

Answer:

i think its b

Explanation:

im not very sure

An electron moves through a region of crossed electric and magnetic fields. The electric field E = 3059 V/m and is directed straight down. The magnetic field B = 1.14 T and is directed to the left. For what velocity v of the electron into the paper will the electric force exactly cancel the magnetic force?

Answers

Answer:

v = 2683.33 m/s

Explanation:

The magnetic force and the electric force on the electron must be the same, in order for them to cancel each other:

[tex]Electric\ Force = Magnetic\ Force\\Eq = qvBSin\theta \\\\v = \frac{E}{BSin\theta}[/tex]

where,

v = velcoity of electron = ?

E = Electric Field = 3059 V/m

B = Magnetic Field = 1.14 T

θ = Angle between velocity and magnetic field = 90°

Therefore,

[tex]v = \frac{3059\ V/m}{(1.14\ T)Sin90^o}[/tex]

v = 2683.33 m/s

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