Answer:
h = 5.38 10¹⁶ m
Explanation:
Let's start this exercise by assuming that all the potential energy of the electron is converted into kinetic energy, let's use the conservation of energy
starting point. Just before ionization
Em₀ = U = qE
final point. Right after ionization
Em_f = K = ½ m v²
Energy is conserved
Em₀ = Em_f
q E = ½ m v²
v² = 2qE / m
Now we can use the relationship between net work and kinetic energy
W_net = ΔK
net work is the work done by the electron minus the binding energy with the atom, called the work function, Ф = 3 10-19 J
W - Ф = K_f - K₀
we assume that the electron converts all its initial initial kinetic energy to be zero
W -Ф = ½ m v² - 0
W = ½ m v² +Ф
we substitute
W = 1/2 m 2qE/m + E
W = qE +Ф
W = 1.6 10⁻¹⁹ 3 10⁶ + 3 10⁻¹⁹
W = 4.8 10⁻¹³ + 3 10⁻¹⁹
W = 4.8 10⁻¹³ J
When the electron is in air, its kinetic energy can be transformed into gravitational potential energy
As the electron is in the air, all work is transformed into scientific energy
W = K
starting point Em₀ = K = W
end point Em_F = U = m g h
energy conservation Em₀ = Em_f
W = m g h
h = [tex]\frac{W}{mg}[/tex]
let's calculate
h = [tex]\frac{4.8 \ 10^{-13} x}{9.1 \ 10^{-31} \ 9.8 }[/tex]
h = 5.38 10¹⁶ m
Electron involved in making in spark travel through the air before it collides with an atom will be at the distance of 5.38 10¹⁶ m.
What is an electric field?An electric field is an electric property that is connected with any location in space where a charge exists in any form. The electric force per unit charge is another term for an electric field.
Let's begin this exercise by assuming that all of the electron's potential energy is turned into kinetic energy, and then we'll apply the law of conservation of energy.
Energy before ionization;
[tex]\rm Em_0 = U = qE[/tex]
Energy after ionization;
[tex]Em_f = K = \frac{1}{2} mv^2[/tex]
From the law of conservation of energy principle;
[tex]Em_0 = Em_f \\\\ q E =\frac{1}{2} m v^2\\\\ v^2 = \frac{2qE }{m}[/tex]
The relationship between net work and kinetic energy;
[tex]W_{net} = \triangle K[/tex]
The work function is defined as net work, which is the work done by the electron minus the binding energy with the atom.
[tex]W - \phi = K_f - K_0[/tex]
[tex]W = K_f+ \phi[/tex]
[tex]W = \frac{1}{2} m \times \frac{2qE}{m} + E\\ \\W = qE + \phi \\\\ \rm W = 1.6 \times 10^{-19}\times 3 \tims 10^6 3 10⁶ +3 \times 10^{-19} \\\\ W = 4.8 \times 10^{-13}+ 3 \times 10^{-19}\\\\ W = 4.8 \times 10^{-13} J[/tex]
EMF at starting point;
[tex]\rm Em_0 = K = W[/tex]
EMF at the endpoint;
[tex]\rm Em_F = U = m g h[/tex]
From the law of conservation of energy principle;
[tex]Em_0 = Em_f \\\\ W = m g \\\\ h = \frac{W}{mg}\\\\\ h = \frac{4.8 \timjes 10^{-13}}{9.1 \times 10^{-31} \times 9.81 }\\\\ \rm h= 5.38 \times 10^{16}[/tex]
Hence electron involved in making in spark travel through the air before it collides with an atom will be at a distance of 5.38 10¹⁶ m.
To learn more about the electric field refer to the link;
https://brainly.com/question/26690770
. Monochromatic light illuminates two slits that are 0.33 mm apart. The adjacent bright lines of the interference pattern on a screen 2.30 m away from the slits are 0.44 cm apart. What is the wavelength of the light
Answer:
the wavelength of the light is 6.313 × 10⁻⁷ m
Explanation:
Given the data in the question;
for a double slit interference;
θ = nλ/d
for adjacent lines
θ = λ/d
and d = 0.33 mm = 0.00033 m
and θ = 0.44 × 10⁻² m / 2.30 m
so
λ = θ × d
λ = ( 0.44 × 10⁻² m / 2.30 m ) × 0.00033 m
λ = 0.001913043478 × 0.00033 m
λ = 6.313 × 10⁻⁷ m
Therefore, the wavelength of the light is 6.313 × 10⁻⁷ m
A researcher would like to perform an experiment in a zero magnetic field, which means that the field of the earth must be canceled. Suppose the experiment is done inside a solenoid of diameter 1.0 m, length 4.6 m , with a total of 5000 turns of wire. The solenoid is oriented to produce a field that opposes and exactly cancels the 52 μT local value of the earth's field.
What current is needed in the solenoid's wires?
Express your answer to two significant figures and include the appropriate units.
Answer:
I = 3.81 x 10⁴ A
Explanation:
The magnetic field of a solenoid must be equal to the field of earth:
[tex]Field\ of\ Earth = Field\ of\ Solenoid\\52\ T = \mu n I\\I = \frac{52}{\mu n}[/tex]
where,
I = current passing through solenoid = ?
μ = permeability of free space = 4π x 10⁻⁷ N/A²
n = no. of turns per unit length = [tex]\frac{5000\ turns}{4.6\ m}[/tex] = 1086.96 /m
Therefore,
[tex]I = \frac{52\ T}{(4\pi\ x\ 10^{-7}\ N/A^2)(1086.96\ /m)}[/tex]
I = 3.81 x 10⁴ A
A 51.0 kg crate, starting from rest, is pulled across a floor with a constant horizontal force of 225 N. For the first 10.0 m the floor is frictionless, and for the next 10.5 m the coefficient of friction is 0.17.
What is the final speed of the crate after being pulled these 20.5 meters?
Answer:
The final speed of the crate is 12.07 m/s.
Explanation:
For the first 10.0 meters, the only force acting on the crate is 225 N, so we can calculate the acceleration as follows:
[tex] F = ma [/tex]
[tex] a = \frac{F}{m} = \frac{225 N}{51.0 kg} = 4.41 m/s^{2} [/tex]
Now, we can calculate the final speed of the crate at the end of 10.0 m:
[tex] v_{f}^{2} = v_{0}^{2} + 2ad_{1} [/tex]
[tex] v_{f} = \sqrt{0 + 2*4.41 m/s^{2}*10.0 m} = 9.39 m/s [/tex]
For the next 10.5 meters we have frictional force:
[tex] F - F_{\mu} = ma [/tex]
[tex] F - \mu mg = ma [/tex]
So, the acceleration is:
[tex] a = \frac{F - \mu mg}{m} = \frac{225 N - 0.17*51.0 kg*9.81 m/s^{2}}{51.0 kg} = 2.74 m/s^{2} [/tex]
The final speed of the crate at the end of 10.0 m will be the initial speed of the following 10.5 meters, so:
[tex] v_{f}^{2} = v_{0}^{2} + 2ad_{2} [/tex]
[tex] v_{f} = \sqrt{(9.39 m/s)^{2} + 2*2.74 m/s^{2}*10.5 m} = 12.07 m/s [/tex]
Therefore, the final speed of the crate after being pulled these 20.5 meters is 12.07 m/s.
I hope it helps you!
1+1=69 how is it possible
Answer:
you add 67 to 1+1 is this clear also chicken nuggets
Answer:
i dont know
Explanation:
3. Provide two examples of static electric charge.
Answer: 1. walking across a carpet and touching a metal door handle 2. pulling your hat off and having your hair stand on end.
Explanation
:)
Let's explore the assumptions we made. Look closely at Jessie's motion as she runs. In calculating her power output, we assumed that the work she did was equal to the work done by the force of gravity on her body. Do you think that is a good assumption
Answer:
No, it is not a good assumption
Explanation:
From the given information:
The work Jessie did was quite more than the work done by the force of gravity. This is because the gravity of the force on her body is perpendicular to its motion and the work done by Jessie is due to the muscular force of her body. Hence, the total power she produced is more than the calculated amount.
3.
Two Cars, A and B, (starting, at the same time, from the same point) are moving
with average speeds of 40 km/h and 50 km/h, respectively, in the same direction.
Find how far will Car B be from Car A after 3 hours.
Answer:
car B will be 30 Km ahead of car A.
Explanation:
We'll begin by calculating the distance travelled by each car. This is illustrated below:
For car A:
Speed = 40 km/h
Time = 3 hours
Distance =?
Speed = distance / time
40 = distance / 3
Cross multiply
Distance = 40 × 3
Distance = 120 Km
For car B:
Speed = 50 km/h
Time = 3 hours
Distance =?
Speed = distance / time
50 = distance / 3
Cross multiply
Distance = 50 × 3
Distance = 150 Km
Finally, we shall determine the distance between car B an car A. This can be obtained as follow:
Distance travelled by car B (D₆) = 150 Km
Distance travelled by car A (Dₐ) = 120 Km
Distance apart =?
Distance apart = D₆ – Dₐ
Distance apart = 150 – 120
Distance apart = 30 Km
Therefore, car B will be 30 Km ahead of car A.
How far could you walk backwards in one hour? Use your speed from the 10m test to calculate the answer. Show your work or you will not receive credit.
Answer: Sweetheart i'm not walking backward for an hour for your little assignment
Explanation: Do it yourself lazy! Have a great day!
In the playground game of tetherball, a ball tied to a rope circles a pole, wrapping the rope around the pole is it goes. Opponents compete to wrap the ball around the pole in one direction or the other; the game ends when the rope is entirely wrapped around the pole and the ball touches the pole. If you get the ball going around in one direction, as the rope shortens and the ball goes in smaller and smaller circles, the ball goes around with a shorter and shorter period.
Required:
Explain why this happens.
As the rope becomes shorter, the length of the rope is decreased and the centripetal force decreases according causing the ball to move in smaller circles.
What is centripetal force?The centripetal force is defined as the force that keeps an object moving in a circular path. Also, the centripetal force is equal to the tension in the rope and the tension in the rope depends on the length of the rope.
As the rope shortens, the tension in the rope decreases and the centripetal force on the ball decreases hence the ball moves in smaller and smaller circles, the ball goes around with a shorter and shorter period.
Learn more about centripetal force: https://brainly.com/question/11324711
a solid sphere and a hollow sphere with equal mass are rotated about an axis through their centers. both spheres experience equal torque. which sphere will reach a speed of 10 rad/s first? Explain your answer.
Answer:
Solid sphere
Explanation:
According to the given situation, the solid sphere would contain the less moment of inertia because it would carry large mass that closed to the axis of rotation
Also if there is a less moment of inertia so there would be high angular acceleration under a torque
α = τ/I
So the solid sphere would reach a speed of 10 rad/s first
A police siren of frequency fsiren is attached to a vibrating platform. The platform and siren oscillate up and down in simple harmonic motion with amplitude Ap and frequency fp. Use v for the speed of sound. Part A Find the maximum sound frequency that you would hear at a position directly above the siren. At what point in the motion of the platform is the minimum frequency heard
Answer:
he maximum frequency occurs when the denominator is minimum
f’= f₀ [tex]\frac{343}{343 + v_s}[/tex]
Explanation:
This is a doppler effect exercise, where the sound source is moving
f = fo [tex]\frac{v}{v-v)s}[/tex] when the source moves towards the observer
f ’=f_o [tex]\frac{v}{v+v_{sy}}[/tex] Alexandrian source of the observer
the maximum frequency occurs when the denominator is minimum, for both it is the point of maximum approach of the two objects
f’= f₀ [tex]\frac{343}{343 + v_s}[/tex]
A pulley in the shape of a solid cylinder of mass 1.50 kg and radius 0.240 m is free to rotate around a horizontal shaft along the axis of the pulley. There is friction between the pulley and this shaft. A light, nonstretching cable is wrapped around the pulley, and the free end is tied to a 2.00 kg textbook. You release the textbook from rest a distance 0.900 m above the floor. Just before the textbook hits the floor, the angular speed of the pulley is 10.0 rad/s. What is the speed of the textbook just before it hits the floor
Answer:
the speed of the textbook just before it hits the floor is 2.4 m/s
Explanation:
Given the data in the question;
mass of pulley = 1.50 kg
radius of pulley = 0.240 m
mass of text book = 2.0 kg
height from which text book was released = 0.9 m
angular speed of the pulley = 10.0 rad/s
the speed of the textbook just before it hits the floor = ?
the speed of the textbook v = angular speed of the pulley × radius of pulley
we substitute
v = 10.0 rad/s × 0.240 m
v = 2.4 m/s
Therefore, the speed of the textbook just before it hits the floor is 2.4 m/s
help me besties PLEASE ;-;
Answer:
Current in resistors = 1.5 amp
Current in resistors = 0.18 amp
P = 93.75 watts
Explanation:
Given:
1. Three 5 ohm resistor(series)
Voltage = 10 volt
2. Three 5 ohm resistor(parallel)
Voltage = 9 volt
3. Three 5 ohm resistor(series)
Voltage = 6 volt
Find:
Current in resistors
Current in resistors
Total power of circuit
Computation:
1. Total resistor (Series) R = R1 + R2 + R3
Total resistor (Series) R = 5 + 5 + 5
Total resistor (Series) R = 15 ohm
I = V/R
Current in resistors = (15)/(10)
Current in resistors = 1.5 amp
2. Total resistor (Series) R = 1/[1/R1 + 1/R2 + 1/R3
Total resistor (Series) R = 1[1/5 + 1/5 + 1/5]
Total resistor (Series) R = 1.67 ohm
I = V/R
Current in resistors = (1.67)/(9)
Current in resistors = 0.18 amp
3. Total resistor (Series) R = R1 + R2 + R3
Total resistor (Series) R = 5 + 5 + 5
Total resistor (Series) R = 15 ohm
I = V/R
I = (15)/(6)
I = 2.5 amp
P = I²(R)
P = (2.5)²(15)
P = 93.75 watts
A drone accelerates from rest to a speed of 300 m/s in 3 s. What is the acceleration of the drone? How far will the drone go?
Answer:
(i) 100 m/s²
(ii) 450 m
Explanation:
From the question,
Using,
(i) a = (v-u)/t................. Equation 1
Where a = acceleration of the drone, v = final velocity of the drone, u = Initial velocity of the drone, t = time.
Given: v = 300 m/s, u = 0 m/s (from rest), t = 3 s
Substitute these values into equation 1
a = (300-0)/3
a = 300/3
a = 100 m/s²
Hence the acceleration of the drone is 100 m/s²
(ii) using,
s = ut+at²/2.................... Equation 2
Where s = distance traveled by the drone.
also substitute the values above into equation 2
s = 0(3)+100(3²)/2
s = 50×9
s = 450 m
A 69.5-kg person throws a 0.0475-kg snowball forward with a ground speed of 31.5 m/s. A second person, with a mass of 57.5 kg, catches the snowball. Both people are on skates. The first person is initially moving forward with a speed of 2.35 m/s, and the second person is initially at rest. What are the velocities of the two people after the snowball is exchanged
Answer:
- After throwing the snow, velocity of the thrower is 2.33 m/s
- the velocity of the receiver is 0.026 m/s
Explanation:
Given the data in the question;
Using conservation of momentum,
Initial thrower has a momentum of mv; [tex]m_{total[/tex]v
(69.5 kg + 0.0475 kg) × 2.35 m/s = 163.4366 kg.m/s
Now, When he throws it at 31.5 m/s, these constitutes a momentum of;
(0.0475 kg )(31.5 m/s) = 1.49625 kg.m/s
hence his momentum now is: 163.4366 - 1.49625 = 161.94035 kg.m/s
To get his velocity, we say;
161.94035 = mv
{ he lost weight of the snow ball so, m = 69.5 kg )
161.94035 = 69.5 × v
v = 161.94035 / 69.5
v = 2.33 m/s
Therefore, After throwing the snow, velocity of the thrower is 2.33 m/s
Next is the Receiver;
the receiver will gain momentum of 1.49625 kg.m/s
he has no momentum initially and after he catches the snow ball;
1.49625 kg.m/s = mv
1.49625 kg.m/s = ( 57.5 kg + 0.0475 kg ) × v
1.49625 kg.m/s = 57.5475 kg × v
v = ( 1.49625 kg.m/s ) / 57.5475 kg
v = 0.026 m/s
Therefore, the velocity of the receiver is 0.026 m/s
One of the advantages of alternating current (ac) over direct current (dc) is the ease with which voltage levels can be increased or decreased.
a. True
b. False
Answer:
True
Explanation:
In an alternating current, voltage levels can be easily increased or decreased as per the requirements of the energy distribution in practical world.
Hence, the given statement is true
Cindy follows her dog around a circle having a radius of 7.40 m.
a) What distance did she travel?
b) The trip took 54 seconds. What was her speed?
c) What was the magnitude of her velocity?
Answer:
a)=46.49 m
b)=0.861 m/s
c)=0.274 m/s
Explanation:
I am quite confuse with ans C . If it is correct but I can explain .lol
Which one of the statements below is true about mechanical waves?
They must travel in empty space.
They can travel in a vacuum.
Both sound and light are examples of mechanical waves.
They require a medium to travel through.
Answer:
The answer is B
Explanation:
Two satellites are monitored as they orbit the Earth; satellite X is eight (8) times as far from the Earth's center as is satellite Y. Using Kepler's 3rd Law, by what factor is the the period (or revolution) of satellite X that of satellite Y
Answer:
[tex]\frac{T_x}{T_y} = 22.63[/tex]
Explanation:
Kepler's third law is an application of Newton's second law for circular motion
T² = K a³
let's apply this expression for each satellite
satellite X
Tₓ² = K aₓ³
satellite Y
[tex]T_y^2 = K a_y^3[/tex]
the relation of the periods is
[tex]\frac{T_x}{T_y} = \sqrt{ (\frac{a_x}{a_y} )^3 }[/tex]
they indicate us
aₓ = 8 a_y
substitutes
[tex]\frac{T_x}{T_y} = 8^{3/2}[/tex]
[tex]\frac{T_x}{T_y} = 22.63[/tex]
Thomson observed that cathode beams can pass undeflected through crossed electric and magnetic fields. Which of the following quantities must then be common to the particles making up these beams? A. Mass B. Size C. Magnitude of charge D. Sign of charge E. Sign and magnitude of charge F. Velocity
Answer:
e must have the charge of the particle
Explanation:
In this experiment, the particles that the cathode rays are found where from an electric field and another magnetic field, for the particle to pass without deviating the magnetic force must have the same modulus of the entricar force, and be in the opposite direction.
the expression for the magnetic force is
F_m = q v xB
the expression for the electric force is
F_e = q E
when warning the check two formulas we must have the charge of the particle
A rocket weighs 1.000. N on the surface of Earth. What is its weight at a distance of two Earth radii above the
surface of Earth?
P.5B
0 111.0 N
250.0 N
333.0 N
5000 N
Answer:
0 111.0N be cause the rest do not add up
Someone please help me...
the distance from the Earth to the sun equals 1 AU. Neptune is 30 AU from the sun. How far is Neptune from the Earth?
Answer:
1 astronomical unit, or AU, is the average distance from the Earth to the Sun; that's about 150 million km. So, Neptune's average distance from the Sun is 30.1 AU. Its perihelion is 29.8 AU, and it's aphelion is 30.4 AU.
Short Answer: it is 29
Explanation:
sorry if its wrong
Answer:
29
Explanation:
I just took a test! not only that but the other person who answered this question had the corrected answer.
a wave travels one complete cycle in20sec and has wavelength of 1000mm.what is the speed
Answer:
20000
Explanation:
Speed = Wavelength x Wave Frequency. In this equation, wavelength is measured in meters and frequency is measured in hertz (Hz), or number of waves per second. Therefore, wave speed is given in meters per second, which is the SI unit for speed.
. Estimate the buoyant force that air exerts on you. (To do this, you can estimate your volume by knowing your weight and by assuming that your weight density is a bit less than that of water.)
Answer:
[tex]0.886[/tex] N buoyant force is exerted by air
Explanation:
My weight is [tex]75[/tex] Kg
Weight = mass * gravity
As we know
Buoyant Force is equal to the product of density * acceleration due to gravity and volume of the body
Assuming weight density is a bit less than that of water or equal to water i.e [tex]997.77[/tex] kg/m3
Volume is equal to mass / density
[tex]= 75[/tex] Kg * g/[tex]997.777[/tex]
[tex]= 0.0751[/tex] * g
Buoyant Force
= Volume * g * density
[tex]= 0.0751 * 9.8 * 1.2041[/tex]kg/m3
[tex]= 0.886[/tex] N
PLEASE HELP ME WITH THIS ONE QUESTION
A piston has a volume change of 7 x 10^-6 m^3. Assuming atmospheric pressure is 101,325 J, what is the work needed to change the piston volume?
Correct question:
A piston has a volume change of 7 x 10^-6 m^3. Assuming atmospheric pressure is 101,325 Pa, what is the work needed to change the piston volume?
Answer:
The work needed to change the piston volume is 0.709 J
Explanation:
Given;
volume of the piston, V = 7 x 10⁻⁶ m³
atmospheric pressure, P = 101,325 Pa
The work needed to change the piston volume is calculated as follows;
W = PV
W = (7 x 10⁻⁶ m³) x (101,325 Pa)
W = 0.709 J
Therefore, the work needed to change the piston volume is 0.709 J
35 POINTSS!!! PLSSSS HELLPPP!!!
Work is the transfer of power from one object to another.
Please select the best answer from the choices provided
T
F
Answer:
T
beacuse:
Energy can be transferred from one object to another by doing work. ... When work is done, energy is transferred from the agent to the object, which results in a change in the object's motion (more specifically, a change in the object's kinetic energy).
Sound wave with of frequency of 300 HZ is traveling with a wavelength of 1 m what is the speed?
Answer:
300m/s
Explanation:
f = c/λ
f = frequency
c = speed
λ = wave length
f = c/λ
300 = c/1
c = 300m/s
Which is true?
a) A changing magnetic field produces a constant perpendicular magnetic field.
b) A changing magnetic field produces a changing perpendicular magnetic field.
c) A changing magnetic field produces a constant parallel magnetic field.
d) A changing magnetic field produces a changing parallel magnetic field.
e) A changing magnetic field produces an electric field.
Answer:
e) A changing magnetic field produces an electric field.
Explanation:
Ok, we start with a magnetic field and let's study how it affects the motion of a single electron. As the magnetic field changes, it will cause an electromotive force, that moves the electron, and because now we have a moving electron, now we will have an electric field. (Such that the direction of the electromotive force opposes the direction in which the magnetic field changes). This also can be deduced if we look at the third Maxwell's equation:
dE/dx = -dB/dt
This says that the spatial change in an electric field depends on how the magnetic field changes as time pass.
Then the correct option is e) A changing magnetic field produces an electric field.
All EM waves (light waves) travel at the same speed through the vacuum of space. If the different types of waves are distinguished by their frequency, what basic characteristic of the waves determines their difference
Answer:
Their different wavelengths.
Explanation:
trust me
All EM waves (light waves) travel at the same speed through the vacuum of space. If the different types of waves are distinguished by their frequency, the basic characteristic of the waves that determine their difference is the wavelength of the electromagnetic waves.
What is Wavelength?It can be understood in terms of the distance between any two similar successive points across any wave for example wavelength can be calculated by measuring the distance between any two successive crests.
It is the total length of the wave for which it completes one cycle.
The wavelength is inversely proportional to the frequency of the wave as from the following relation.
C = νλ
where c is the speed of light
ν is the frequency of the wave
λ is the wavelength of the wave
As we know electromagnetic waves (light waves) travel at the same speed through the vacuum of space which is the speed of light which is 3×10⁸ meter/second
All EM waves (light waves) travel at the same speed through the vacuum of space. If the different types of waves are distinguished by their frequency, the basic characteristic of the waves that determine their difference is the wavelength of the electromagnetic waves.
Learn more about wavelength from here
brainly.com/question/7143261
#SPJ2
(20 points) You are at the center of a boat and have been rowing the boat for a long time. You weigh only 80 kg and your 120 kg buddy Bubba has been riding at the front of your 60 kg, 4 m long boat. You come to a stop in the water and then switch places. A) What is the center of mass before you switch places
Answer:
Explanation:
From the given information:
Let the first weight be [tex]m_ 1[/tex] = 80 kg
The weight of the buddy be [tex]m_2[/tex] = 120 kg
The weight of Bubba be [tex]m_3[/tex] = 60 kg
Also, since you and Budda are a distance of 4m to each other, then the length to which both meet buddy will be:
[tex]x_1 = x_3 = \dfrac{4}{2} \\ \\ = 2[/tex]
The length of the boat be [tex]x_2[/tex] = 4 m
∴
We can find the center of mass of the system by using the formula:
[tex]X_{CM} = \dfrac{m_1x_1+m_2x_2+m_3x_3}{m_1+m_2+m_3} \\ \\ X_{CM} = \dfrac{(80 \times 2)+(120\times4)+(60\times2)}{80+120+60} \\ \\ X_{CM} = \dfrac{160+480+120}{260} \\ \\ \mathbf{X_{CM} = 2.923}[/tex]