Answer:
The luminosity remains the same, but the apparent brightness is decreased by a factor of four.
Explanation:
The apparent brightness, F = L/4πr² where L = luminosity and r = distance between us and the star.
Since L is independent of the distance between us and the star, it is constant, then
F ∝ 1/r²
So, F₁/F₂ = r₂²/r₁² where F₁ = apparent brightness at r₁ and F₂ = apparent brightness at r₂
If the distance is doubled, that is r₂ = 2r₁, then
F₁/F₂ = r₂²/r₁²
F₁/F₂ = (2r₁)²/r₁²
F₁/F₂ = 4r₁²/r₁²
F₁/F₂ = 4
F₂ = F₁/4
So, since the luminosity is constant, the luminosity remains the same, but the apparent brightness is decreased by a factor of four.
A 3kg object moving at 4 m/s encounters a 20 N resistive force over a duration of 0.20 seconds. The impulse experienced by this object is _____
Answer:
the impulse experienced by this object is 4 Ns
Explanation:
Given;
mass of the object, m = 3 kg
velocity of the object, v = 4 m/s
resistive force, F = 20 N
duration of impact, t = 0.2 s
The impulse experienced by this object is calculated as follows;
J = F x t
J = 20 x 0.2
J = 4 Ns
Therefore, the impulse experienced by this object is 4 Ns
A solenoid coil 10cm long has 40 turns cm-1. The current rises from zero to its maximum value of 5.0000 A and 0000.01s when the switch is closed. Find the energy stored in magnetic field if the area of cross section of solenoid be 28 centimeter square.
Answer:
Explanation:
Energy stored in a solenoid per unit volume = B₀² / (2μ₀)
B₀= μ₀ n I₀
n is no of turns per unit length .
Energy stored in a solenoid per unit volume = ( μ₀ n I₀)² / (2μ₀)
=μ₀n²I₀²/2
n = 40 turns / cm = 40 x 100 turns per meter.
I₀ = 5000A .
Putting the values
Energy stored in a solenoid per unit volume
= 4π x 10⁻⁷ x 40 x 10² x 5000² /2
= 1256 J/ m³
Volume of solenoid = cross sectional area x length
= 28 x 10⁻⁴ x .10 = 2.8 x 10⁻⁴ m³
Total energy stored = 1256 J / m³ x 2.8 x 10⁻⁴ m³
= .35 J .
The Sun emits a solar flare directly aimed at Earth. Which instrument on an orbiting satellite would detect the flare first?
Answer:
X-ray Telescope
Explanation:
X-ray Telescope which can be either hard or soft is an instrument on an orbiting satellite that would detect the flare first.
This is because X-ray Telescope is technically designed to detect and determine X-rays or radio and optical emissions from flares, from places or points beyond Earth's atmosphere.
Which energy transformation occurs in plants, allowing them to make food?
Which indicates that light travels in straight lines?
A. Color
B. Pigments
C. Shadows
D. Waves
Answer:
A
Explanation:
Answer:
C
Explanation:
Light travels in straight lines
Shadows are evidence of light travelling in straight lines. An object blocks light so that it can't reach the surface where we see the shadow.
What is the net force acting upon this object? *
3N : to the left
5 N : to the right
Answers to choose from:
2 N Right
BN
2 N Left
5 N Right
2 N Right
.. .. .. .. .. .. .. ..
Answer:
2 N Right
Explanation:
Net force = 5 - 3
= 2 N to the Right
Explain the effects of expansion of water on aquatic life
Answer:
The anomalous expansion of water helps preserve aquatic life during very cold weather. When temperature falls, the top layer of water in a pond contracts, becomes denser and sinks to the bottom. If the temperature falls further, the top layer expands and remains on the top till it freezes.
What 3 things do you need to make an electromagnet ?
Answer:
1. Battery
2. Copper wire
3. Nail or piece of metal (zinc, iron, or steel).
Answer:
magnet coppers wire and piece of metals
The average mass of an adult American female is 75 kilograms. What is the weight of
the average female in pounds?
Answer:
with 75kg --> 165.35 pound(lb)
Explanation:
[tex] \frac{75}{0.45359237} [/tex]
how does increasing and decreasing the temperature affect the kinetic energy of molecules?
Answer:
Amontons's law. If the temperature is increased, the average speed and kinetic energy of the gas molecules increase. ... If the gas volume is decreased, the container wall area decreases and the molecule-wall collision frequency increases, both of which increase the pressure exerted by the gas
Calcula la cantidad de calor que hay que darle a 0,01 l de mercurio para que su temperatura pase de 10 ºC a 25 ºC. Datos: rho=13,6 g/cm3 ; Ar(Hg)=200,6; C=28,1 J/(mol∙K).
Respuesta:
286 J
Explicación:
Paso 1: Convertir 0,01 L de Hg a cm³
Usaremos los siguientes factores de conversion.
1 L = 1000 mL
1 mL = 1 cm³
0,01 L × 1000 mL/1 L × 1 cm³/1 mL = 10 cm³
Paso 2: Calcular la masa (m) correspondiente a 10 cm³ de Hg
La densidad de Hg es 13,6 g/cm³.
10 cm³ × 13,6 g/cm³ = 136 g
Paso 3: Calcular los moles(n) correspondientes a 136 g de Hg
La masa molar de Hg es 200,6 g/mol.
136 g × 1 mol/200,6 g = 0,678 mol
Paso 4: Calcular la cantidad de calor requerido (Q)
Usaremos la siguiente fórmula.
Q = c × n × (T₂ - T₁)
donde,
c: calor específico del Hg (28,1 J/mol.K = 28,1 J/mol.K)
T₂ y T₁: temperaturas final e inicial, respectivamente
Q = (28,1 J/mol.°C) × 0,678 mol × (25°C - 10 °C) = 286 J
1. A massive object can distort the light of more distant objects behind it through the phenomenon that we call ________. 2. ________ are defined as subatomic particles that have more mass than neutrinos but do not interact with light. 3. The _____________ of spiral galaxies provide strong evidence for the existence of dark matter. 4. Models show that the _________ of the universe is better-explained when we include the effects of dark matter along with the effects of luminous matter.
Answer:
1. Gravitational lensing.
2. Weakly interacting massive particles (WIMPs).
3. Rotation curves.
4. Large-scale structure.
Explanation:
In science, matter can be defined as anything that has mass and occupies space. Any physical object that is found on earth is typically composed of matter. Matter are known to be made up of atoms and as a result has the property of existing in states.
Generally, matter exists in three (3) distinct or classical phases and these are; solid, liquid and gas.
Light wave can be defined as an electromagnetic wave that do not require a medium of propagation for it to travel through a vacuum of space where no particles exist.
The following statements are matched to give the characteristics of matter with respect to light;
1. A massive object can distort the light of more distant objects behind it through the phenomenon that we call: gravitational lensing. The gravitational field distorts and magnifies light from a distant galaxy such as quasars.
2. Weakly interacting massive particles (WIMPs): are defined as subatomic particles that have more mass than neutrinos but do not interact with light.
3. The rotation curves of spiral galaxies provide strong evidence for the existence of dark matter.
4. Models show that the large-scale structure of the universe is better-explained when we include the effects of dark matter along with the effects of luminous matter.
what is the another name ffo
Answer:
sorry buh I don't get the question
A van accelerates from 4m/s to 20m/s in 8s. How far does it travel in this time?
Answer:
96 m
Explanation:
Given,
Initial velocity ( u ) = 4 m/s
Final velocity ( v ) = 20 m/s
Time ( t ) = 8 s
Let Acceleration be " a ".
Formula : -
a = ( v - u ) / t
a = ( 20 - 4 ) / 8
= 16 / 8
a = 2 m/s²
Let displacement be " s ".
Formula : -
s = ut + at² / 2
s = ( 4 ) ( 8 ) + ( 2 ) ( 8² ) / 2
= 32 + ( 2 ) ( 64 ) / 2
= 32 + ( 2 ) ( 32 )
= 32 + 64
s = 96 m
Therefore, it travels 96 m in time 8 s.
Round the following off to required number of significant figures.
137 (2 significant figures)
Answer:
140
hope this helps
have a good day :)
Explanation:
HURRY PLEASE HELP ME
Which of the following is an incorrect statement?
A pencil on a table contains potential energy.
Potential energy does work.
All objects contain potential energy.
Potential energy is stored energy.
Answer:
I think it is Potential energy is stored energy
Explanation:
Answer:
potential energy is stored energy, to my knowledge
Brainliest for correct answer :)
An object travelling for 20 seconds initially travels at 10ms-1 and increases its speed to 40ms-1 what is its acceleration?
Answer:
Acceleration a =-1.75 m/s²
Explanation:
Given:
Initial speed u = 24 m/s
Final speed v = 10 m/s
Time taken t = 8 sec
Find:
Acceleration a
Computation:
a = (v-u)/t
a = (10-24)/8
a = -14 / 8
Acceleration a =-1.75 m/s²
What is the highest Mountain, and where is it?
Answer:
Mount Everest is Earth's highest mountain above sea level, located in the Mahalangur Himal sub-range of the Himalayas. The China–Nepal border runs across its summit point. Its elevation of 8,848.86 m was most recently established in 2020 by the Nepali and Chinese authorities.
Explanation:
What protects and supports body organs and provides a framework the muscles use to support movements,made up of bones and joints
Answer: Skeletal system
Explanation:
The skeletal system is a framework of the body. It comprises of connective tissues like bones, tendons, ligaments, and cartilage. All these connective tissues of the skeletal system connect with the muscular system of the body this helps in the locomotion of the body. The conjugation of the musculoskeletal system will also protect the internal organs of the body and will prevent the internal organs from injuries.
Answer:
the skeletal system
Explanation:
Because our skeleton is the framework of the body. :)
Please help!
A string of length Lis clamped at each end. It CAN'T vibrate with a 1
equal to
Answer:
4L is the answer
Explanation:
The inventor of the electric cell was:
O Coulomb
Franklin
o Gilbert
O Volta
Answer:
The inventor of the electric cell was:
Alessandro Volta (in other words, Volta)
Explanation:
Answer:
Volta
Hope this helped you!!
Brainliest plsss
Explanation:
Alessandro Volta, in full Conte Alessandro Giuseppe Antonio Anastasio Volta, (born February 18, 1745, Como, Lombardy [Italy]—died March 5, 1827, Como), Italian physicist whose invention of the electric battery provided the first source of continuous current
31. If Earth's mass was cut in half, your weight
would
Answer:
it would decrease to one half your original weight
Explanation:
The heat current across a certain cinductive material is H. If the cross-sectional area of the material is tripled and everything else remains the same, how is the heat current affected?
Answer:
Resistance is inversely proportional to the cross section area of the material, hence when cross sectional area is tripled, also resistance triples.
Since heat is caused due to resistance, also heat current triples.
My next photo
How's it
Answer:
Good............................
Every chemical compound is unique and different from the ____________________ it contains.
a.
molecules
c.
elements
b.
hydrogen
d.
gas
Answer:
C is your answer fam.
Explanation:
A 1220-w hair dryer is used by several members of the family for a total of 30 min per day during a 30 day month. How much elecrical energy is consumed by the hair dryer during the month give your answer in kilowatt hours
Answer:
Energy = 18.3 Kilowatt-hour
Explanation:
Given the following data;
Power = 1220 Watts
Time = 30 * 30 = 900 minutes to hours = 900/60 = 15 hours
To find the energy consumption;
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]
Making energy the subject of formula, we have;
Energy = power * time
Energy = 1220 * 15
Energy = 18300 Joules
To convert energy to Kilowatt-hour;
Energy = 18300/1000
Energy = 18.3 Kilowatt-hour
A balloon is rubbed against a student's hair and then touched to a
wall. The balloon sticks to the wall due to:
(a) magnetic forces between the particles of the balloon and the
particles of the wall
(b) electrostatic forces between the particles of the balloon and
the particles of the wall
(c) magnetic forces between the particles of the wall
(d) electrostatic forces between the particles of the balloon
Answer:
B. electrostatic forces between the particles of the balloon and the particles of the wall
B
how much force is required to accelerate a 12 kg mass at m 5 m/s
Answer:
60N
Explanation:
force = mass * acceleration
force = 12 * 5
force =60N
In 1993, the gold reserves in the United States were about 8.490 × 106
kg. If all
that gold were made into a thick wire with a cross-sectional area of 1cm2
, its
total resistance would be about 6.60 × 102 Ω. If the same operation were
applied to the gold reserves of Germany, France, and Switzerland, the
resistances would be 2.40 × 102 Ω, 2.00 × 102 Ω, and 2.00 × 102 Ω,
respectively. Now consider all four resistors connected as shown in the circuit
diagram below. Find the equivalent resistance.
The equivalent resistance of the circuit is 65.98 Ω.
What is Resistor?
A resistor is an electrical component that limits or regulates the flow of electrical current in a circuit. It is designed to provide a specific amount of resistance to the flow of electrons, measured in ohms, and is typically made of a material that can resist the flow of electricity, such as carbon or metal. Resistors are used in a wide range of electronic devices and circuits, from simple LED flashers to complex computer systems.
To find the equivalent resistance of the circuit, we need to use the formula for resistors in parallel:
1/Req = 1/R1 + 1/R2 + 1/R3 + 1/R4
where Req is the equivalent resistance, and R1, R2, R3, and R4 are the resistances of the four resistors.
Substituting the given values, we get:
1/Req = 1/6.60 × 102 + 1/2.40 × 102 + 1/2.00 × 102 + 1/2.00 × 102
1/Req = 0.01515
Req = 65.98 Ω
Therefore, the equivalent resistance of the circuit is 65.98 Ω.
Learn more about Resistor from given link
https://brainly.com/question/17563681
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Una carga de 4 nC es transportada desde el suelo hasta la superficie de una esfera cargada con un trabajo de 7 X 10-5 j. Determinar el potencial eléctrico de la esfera
Respuesta:
2 × 10⁴ V
Explicación:
Paso 1: Información provista
Carga transportada (q): 4 nCTrabajo realizado (W): 7 × 10⁻⁵ JPaso 2: Convertir q a Coulomb
Usaremos el factor de conversión 1 C = 10⁹ nC.
4 nC × 1 C/10⁹ nC = 4 × 10⁻⁹ C
Paso 3: Calcular el potencial eléctrico (V) de la esfera
Usaremos la siguiente fórmula.
V = W/q
V = 7 × 10⁻⁵ J/4 × 10⁻⁹ C = 2 × 10⁴ V