Heritage of Leavitt Using Cepheid variables, the distance to Andromeda of 2.5 million light-years was determined in the 1920s, demonstrating the galaxy's significant distance from the Milky Way.
What does the Cepheid variable do to let us calculate their luminosity?Distance Measuring with Cepheid Variables After determining a distant Cepheid's period, its brightness can be calculated using the known characteristics of Cepheid variables.
How can one determine the distances of star clusters or galaxies using the Cepheid period-luminosity relation?A Cepheid's fluctuation period correlates closely with its luminosity, as Henrietta Swan Levitt observed. The Cepheid becomes increasingly bright as the variability period lengthens. Astronomers have measured the distances to distant galaxies by observing Cepheid variables.
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Only the healthy foods we eat provide
energy to our body
true
false
Answer:
True
Explanation:
Yes absolutely the food which provede us energy is termed as healthy..
will give you brainliest pls help
1. All the relevant resistors are in series, so the total (or equivalent) resistance is the sum of the resistances of the resistors: 20 Ω + 80 Ω + 50 Ω = 150 Ω [choice A].
2. The ammeter will read the current flowing through this circuit. We can find the ammeter reading using Ohm's law in terms of the electromotive force provided by the battery: I = ℰ/R = (30 V)(150 Ω) = 0.20 A [choice C].
3. The voltmeter will measure the potential drop across the 50 Ω resistor, i.e., the voltage at that resistor. We know from question 2 that the current flowing through the resistor is 0.20 A. So, from Ohm's law, V = IR = (0.20 A)(50 Ω) = 10. V, which will be the voltmeter reading [choice F].
4. Trick question? If the circuit becomes open, then no current will flow. Moreover, even if the voltmeter were kept as element of the circuit, voltmeters generally have a very high resistance (an ideal voltmeter has infinite resistance), so the current moving through the circuit will be negligible if not nil. In any case, the ammeter reading would be 0 A [choice B].
Laundry in a clothes dryer often becomes charged with static electricity while drying. Which of these best explains why a clothes dryer often generates static electricity?
A: Heat from the dryer charges the air and produces lightning.
B: Clothes with metal pieces conduct electricity in the dryer.
C: Electrons are transferred as clothes rub against each other in the dryer.
Four round objects of equal mass and radius roll without slipping along a horizontal surface that then bends upward and backward into an arc of half a circle. The objects all have the same linear speed initially. The objects are a hollow cylinder, a solid cylinder, a solid sphere, and a hollow sphere. The objects to go up the arc and exit the are going in the opposite direction they entered without falling off the arc. Now, several trials are run for each object. For each trial, the initial speed of the object is reduced until the object does not make it through the full arc. The speed needed for each object to just make it through the arc is recorded. Which of the following correctly lists the objects in order from fastest to slowest speed needed to make it through the arc?
A. Hollow cylinder, hollow sphere, solid cylinder, solid sphere
B. Hollow cylinder, solid sphere, solid cylinder, hollow sphere
C. Solid sphere, solid cylinder, hollow sphere, hollow cylinder
D. Solid sphere, hollow sphere, solid cylinder, hollow cylinder
E. Hollow sphere, solid cylinder, hollow cylinder, solid sphere
Answer:
A
Explanation:
inertia Equation for All Object is k m R²
inertia Equation of Hollow Cylinder I = m R²
inertia Equation of Solid Cylinder I = ½ m R²
inertia Equation of Hollow Sphere I = ⅔ m R²
inertia Equation of Solid Sphere I = 2/5 m R²
to find the speed needed we can use Mechanical Energy (ME). or Total Energy.
ME = Translation Kinetic Energy + Rotation Kinetic Energi
ME = ½ m v² + ½ I w²
ME = ½ m v² (1 + k)
v² = 2ME / m(1+k)
sinnce all objects have the same mass, we can figure that v² is proportionally with 1/(1+k)
v²(hc) = 1/(1+1) = ½ = 0.5
v = 0.707
v²(sc) = 1/(1+½) = 2/3 = 0.67
v = 0.818
v²(hs) = 1/(1+⅔) = 3/5 = 0.6
v = 0.744
v²(ss) = 1/(1+²/5) = 5/7 = 0.71
v = 0.842
these is the ratio of speed they produce in the end of the arc with initial speed = 0 m/s
so, if we must give speed to the object so that it can reach the end of the arc, the fastest speed is given to hollow cylinder and the slowest speed is given to Solid Sphere
Then the answer is
HC, HS, SC, SS
Solid sphere, solid cylinder, hollow sphere, hollow cylinder correctly lists the objects in order from fastest to slowest speed needed to make it through the arc.
What is inertia?A body's inertia is a characteristic that makes it resist attempts to move it or, if it is already moving, to change the speed or direction of it.
Mathematically:
inertia All Object is = k m R²
inertia of Hollow Cylinder I₁ = m R²
inertia of Solid Cylinder I₂ = ½ m R²
inertia of Hollow Sphere I₃ = ⅔ m R²
inertia of Solid Sphere I₄ = 2/5 m R²
Total kinetic energy of a body while it roll without slipping = Translation Kinetic Energy + Rotation Kinetic Energi
= ½ m v² + ½ I w²
= ½ m v² (1 + k)
= 2 KE / m(1+k)
Since all objects have the same mass and, v² can be expressed as proportionally with 1/(1+k).
For hollow cylinder: v₁² = 1/(1+1) = ½ = 0.5
v₁ = 0.707
For solid cylinder: v₂²= 1/(1+½) = 2/3 = 0.67
v₂ = 0.818
For hollow sphere: v₃² = 1/(1+⅔) = 3/5 = 0.6
v₃ = 0.744
For solid sphere: v₄² = 1/(1+²/5) = 5/7 = 0.71
v ₄= 0.842
The objects in order from fastest to slowest speed needed to make it through the arc are correctly listed as:
solid sphere > solid cylinder > hollow sphere > hollow cylinder.
Option (C) is correct.
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Why is the magnetic force considered to be an action datance force
A Magnets in de bo exert a force
B. Magnets do not have to touch each other to experience a force.
C. Magnets push each other apan to increase the distance between them.
D Magnets mast be large in sire in onder to eden a force that is strong enough to notice
A uniform plank of mass 10kg and length 10m rests on two supports, A and B as shown. A boy of weight 500N stands at a distance of 2m from A. Find the reaction forces U¹ and U² at the supports A and B respectively
Answer:
U² = 142.86 N
U¹ = 357.14 N
Explanation:
Taking summation of the moment about point A, we get the following equilibrium equation: (taking clockwise direction as positive)
[tex]W(2\ m) - U^2(7\ m) = 0[/tex]
where,
W = weight of boy = 500 N
U² = reaction ay B = ?
Therefore,
[tex](500\ N)(2\ m)-(U^2)(7\ m)=0\\U^2=\frac{1000\ Nm}{7\ m}\\[/tex]
U² = 142.86 N
Now, taking summation of forces on the plank. Taking upward direction as positive, for equilibrium position:
[tex]W-U^1-U^2=0\\500\ N - 142.86\ N = U^1\\[/tex]
U¹ = 357.14 N
A student constructs four electric circuits.
Each circuit includes two bulbs and an ammeter.
All the bulbs, all the cells and all the ammeters are identical.
The ammeter readings for the first two circuits are shown.
Use values from the box to complete the ammeter readings for the other two circuits.
Answer:
Part A
The ammeter reading for the current flowing through the second bulb, in the third circuit is 0.43 A
Part B
The ammeter reading for the total current coming from the cell is 0.86 A
Explanation:
The given electric circuit schematics includes;
The number of bulbs in each circuit = 2 bulbs
The number of ammeter in each circuit = 1 ammeter
The number of cells in each circuit = 1
Each circuit have identical bulbs, cells and ammeters
Part A
Ammeter reading for the third circuit
The given reading for the total current going to the cell, [tex]I_T[/tex] = 0.86 A
The reading for the current flowing through one of the bulbs, I₁ = 0.43 A
Therefore, given that the bulbs are arranged in parallel, and the bulbs have identical resistance, 'R', the current flowing in the second bulb, I₂, is given by the current divider rule as follows;
[tex]I_2 = \dfrac{R}{R + R} \times I_T = \dfrac{R}{2 \cdot R} \times I_T = \dfrac{1}{2} \times I_T[/tex]
∴ The ammeter reading for the current flowing through the second bulb, in the third circuit I₂ = (1/2) × (0.86 A) = 0.43 A
Part B
Ammeter reading for the third circuit
The total current coming from the cell = The current passing through the bulbs = I₁ + I₂
The ammeter reading for the total current coming from the cell = 0.43 A + 0.43 A = 0.86 A = [tex]I_T[/tex]
Which colour of light in a prism has the
shortest wavelength? Explain
your answer.( 38 points )
☁️ Answer ☁️
Violet
Explanation:
1. As the full spectrum of visible light travels through a prism, the wavelengths separate into the colors of the rainbow because each color is a different wavelength. Violet has the shortest wavelength, at around 380 nanometers, and red has the longest wavelength, at around 700 nanometers.
2. Isaac Newton's experiment in 1665 showed that a prism bends visible light andthat each color refracts at a slightly different angle depending on the wavelength of the color.
Here's the link if you want to know more:
https://science.nasa.gov/ems/09_visiblelight#:~:text=As%20the%20full%20spectrum%20of%20visible%20light%20travels,has%20the%20longest%20wavelength%2C%20at%20around%20700%20nanometers.
Hope it helps.
Have a nice day noona/hyung.
Answer:
Violet
Explanation:
As the full spectrum of visible light travels through a prism, the wavelengths separate into the colors of the rainbow because each color is a different wavelength. Violet has the shortest wavelength, at around 380 nanometers, and red has the longest wavelength, at around 700 nanometers.
A car increases from 15 km/s to 45 km/s in 5 seconds. Calculate the average acceleration of the car during these 5 seconds. (2 points) A. 6 km/s2 B. 12 km/s2 C. 30 km/s2 D. 60 km/s2
PLEASE ANSWER THIS ASAP I WILL MARK YOU THE BRAINLIEST The actual subject is Science but they dont have that as a option in pick a subject
Answer:
I believe it is D.
Explanation:
I say this because it is position vs. seconds and it makes the most sense based on the markings. Sorry if I am wrong, hope it is right!
Answer: D. 40/15 = 2.67m/s
Explanation:
I hope it is correct
How can I rewrite the equation a - b = d using addition?
Explanation:
A=b+d that is the way to rewrite the equation
Juan is studying a group of cells under a microscope. His teacher tells him that the cells either came from the leaf of a tomato plant or the scale of a lizard. Juan could conclude that the cells came from the tomato plant if they contained?
Answer:
chloroplasts
Explanation:
What are examples of convection currents?
The movement of warm air into cooler air and cooler air into warm air.
The movement of cool water into warmer water and warmer water into the cool water.
The displacement of air/water molecules by other air/water molecules due to varying temperatures.
All of the above.
Answer:
I would say all of the above.
Explanation:
Look below for more examples
How can seismographs be used to predict hurricane intensity?
Answer: The earth is a noisy place. Seismometers, which measure ground movements to detect earthquakes, volcanic eruptions, and manmade explosives, are constantly recording smaller vibrations caused by ocean waves, rushing rivers, and industrial activity.
Explanation:
What are examples of changes in people, animals, or objects that would help you make a claim about their age? NO LINKS OR YOURE GETTING REPORTED. Thanks
It’s Earth Science
Answer:
An example of changes in people based on their age, are mood changes,playfulness and as of objects you can say old or broken, animals can use the same reference as humans, the more mature you are can suggest your older, such as the more worn down your are based on a object
how is momentum of an object related to stopping distance
Answer:
To stop a car must lose its momentum and its kinetic energy. ... If the forces on two cars are equal then the greater the kinetic energy the greater the distance before stopping. But there will be a relationship to the momentum because momentum and mass are both related to the kinetic energy.
What is the velocity of a 65 kg runner with 90 kg m/s of momentum.
Answer:
[tex]\boxed {\boxed {\sf v \approx 1.46 \ m/s}}[/tex]
Explanation:
Momentum is the product of mass and velocity.
[tex]p=mv[/tex]
We know the mass is 65 kilograms and the momentum is 90 kilograms meters per second.
[tex]m= 65 \ kg \\p= 95 \ kg \ m/s[/tex]
Substitute the values into the formula.
[tex]95 \ kg \ m/s= 65 \ kg *v[/tex]
Since we are solving for velocity, we must isolate the variable (v). It is being multiplied by 65 kg. The inverse of multiplication is division, so we divide.
[tex]\frac {95 \ kg \ m/s}{65 \ kg }= \frac {65 \ kg *v}{65 \ kg}[/tex]
[tex]\frac {95 \ kg \ m/s}{65 \ kg }=v[/tex]
The kilograms cancel when divided.
[tex]1.46153846 \ m/s=v[/tex]
Let's round to the nearest hundredth. The 1 (in the thousandth place) tells us to leave the 6.
[tex]1.46 \ m/s \approx v[/tex]
The velocity is approximately 1.46 meters per second.
How tightly packed molecules (particles) are packed in a solid, liquid or gas is the
weight
volume
density
Answer:
I believe it's the weight
Explanation:
Which one of these Target games uses the underhand throw?
A: Golf
B: KanJam
C: Corn-Hole
D: None Of The Above
HELP!!
Answer:
Cornhole
Explanation:
pls answer this question
Explanation:
on the left side the forces add to 150N
on the right side the forces add to 300
you then take away 150 from 300
=150N to the right
answer Is C
When 525 J of heat is added to 7.6 g of metal at 26°C, the temperature increases to 80°C. What is the specific heat of the metal?
Ans the answer is 0.25J
Explanation
i guess
PLEASE HELP ASAP!!!!!!!1
Age of dino: Mesozoic era
End of earth a dessert: End of the Mesozoic
a layer: Paleozoic
Which of the following is NOT true about noon in the Northern Hemisphere, on January 1?
A. The sun has reached its highest altitude for that day.
B. Your shadow is the shortest it will be that day.
C. Your shadow points due north.
D. The Sun is directly overhead.
Answer:
The answer is D
Explanation:
When acceleration and velocity are the in the same direction, the speed will
Answer:
slowing down.
Explanation:
acceleration points in the same direction as the velocity, the object will be speeding up. And if the acceleration points in the opposite direction of the velocity, the object will be slowing down
A projectile only accelerates in which direction?
Answer:
the projectile travels with a constant horizontal velocity and a downward vertical acceleration.
PLEASE ANSWER THIS ASAP I WILL MARK YOU THE BRAINLIEST The actual subject is Science but they dont have that as a option in pick a subject
A 100-watt lightbulb uses 1 kilowatt-hour of electrical
energy when it is on for ten hours. How much energy does
a 25-watt lightbulb use when it is on for ten hours?
Answer:
Energy = 0.25 kilowatt-hour
Explanation:
Given the following data;
Power = 25 Watts
Time = 10 hours
Power can be defined as the energy required to do work per unit time.
Mathematically, it is given by the formula;
[tex] Power = \frac {Energy}{time} [/tex]
To find the energy consumed;
Energy = power * time
Substituting into the formula, we have;
Energy = 25 * 10
Energy = 250 Watt-hour
To convert to kilowatt-hour, we would divide by 1000;
Energy = 250/1000
Energy = 0.25 kilowatt-hour
A small person was running way faster than a bigger person that weighed more collided in a football game. Who would be pushed back or down?
Answer:
smaller one
Explanation:
even though he is moving quicker doesn't mean he will be packing more force in the collision
Figure 3.50 shows a wooden cube floating in water.
When a stone is placed on the wood, it sinks a further 0.2m.
Find the weight of the
(a) wood
(b) stone
(Density of water = 1000kgm^-3]
Answer:
(a) The weight of the wood is approximately 5,886 N
(b) The weight of the stone is approximately 1,962 N
Explanation:
The given parameters are;
The base area of the wood, A = 1 m × 1 m = 1 m²
The depth to which the wood is submerged below the water, d = 0.6 m
The depth further the wood sinks when a stone is placed on the wood, Δd = 0.2 m
The density of water, ρ = 1,000 kg/m³
(a) Archimedes' principle states that the up-thrust, or upward force acting on an object submerged in a fluid, is equal to the weight of the displaced fluid.
For a floating object such as the wood, the up-thrust is equal to the weight of the object
The weight of the water displaced, W = The volume of the displaced water, V × The density of the water, ρ × The acceleration due to gravity, g
W = V × ρ × g
'V' is the same as the volume of the submerged wood, therefore;
V = A × d = 1 m × 1 m × 0.6 m = 0.6 m³
g ≈ 9.81 m/s²
Therefore;
W = 0.6 m³ × 1,000 kg/m³ × 9.81 m/s² ≈ 5,886 Newtons
The weight of the water displaced, W ≈ 5,886 N = The up-thrust = The weight of the wood
∴ The weight of the wood, W ≈ 5,886 N
(b) Similarly, the weight of the stone, [tex]W_{stone}[/tex] is equal to the weight of the additional volume of water displaced
∴ [tex]W_{stone}[/tex] = A × Δd × ρ × g
By plugging in the values, we get
[tex]W_{stone}[/tex] ≈ 1 m² × 0.2 m × 1,000 kg/m³ × 9.81 m/s² = 1,962 N
The weight of the stone, [tex]W_{stone}[/tex] ≈ 1,962 Newtons
A horizontal platform in the shape of a circular disk rotates on a frictionless bearing about a vertical axle through the center of the disk. The platform has a mass of 150 kg, a radius of 2.0 m, and a rotational inertia of 300 kg·m2 about the axis of rotation. A 60 kg student walks slowly from the rim of the platform toward the center. If the angular speed of the system is 1.4 rad/s when the student starts at the rim, what is the angular speed when she is 0.70 m from the center?
Answer: [tex]2.29\ rad/s[/tex]
Explanation:
Given
Mass of Platform M=150 kg
the radius of Platform R=2 m
Moment of inertia of Platform [tex]I=300\ kg.m^2[/tex]
Mass of student [tex]m=60\ kg[/tex]
The initial angular speed of the student is [tex]\omega _1=1.4\ rad/s[/tex]
Initially, the moment of inertia of platform and student is
[tex]I_1=\dfrac{1}{2}MR^2+mR^2\\\\I_1=300+60\times 4=540\ kg.m^2[/tex]
The final moment of inertia
[tex]I_2=\dfrac{1}{2}MR^2+mr^2\\\\I_2=300+60\times 0.7^2=329.4\ kg.m^2[/tex]
Conserving angular momentum
[tex]I_1\omega_1=I_2\omega _2\\\\540\times 1.4=329.4\times \omega_2\\\\\omega_2=\dfrac{756}{329.4}=2.29\ rad/s[/tex]