Answer:
C
Explanation:
Pigments reflect some wavelength of visible light and absorb
An imaginary star is four light years from earth. The star has a planet, upon which a large mirror has been installed. The mirror faces earth. A ten year old boy aims his telescope at the mirror. How old will the boy be when he sees his own reflection?
Answer:
14 years
Explanation:
because the light will take four years to reach the earth. And the star is four light years away from the earth.
Hope that helps you please followAn imaginary star is four light years from earth. The star has a planet, upon which a large mirror has been installed. The mirror faces earth. A ten year old boy aims his telescope at the mirror,then the boy would be 14 years old when he will see his own reflection.
What is a light year?
It can be defined as the distance travelled by the light in one year .it is represented in units of distance such as miles or km.
1 light year is calculated by multiplying the speed of light with the time of one year
1 light year = speed of light × one year time period
1 light year = 3×10⁸ ×(365×24×60×60)
=9.461× 10¹⁵ meter
As given in the problem 10 year old boy aims his telescope at the mirror which is 4 light years away then the light has to travel four years to reach the boy ,then the boy would be 14 year old when he would see his own reflection.
Learn more about light year from here
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A flat, circular, copper loop of radius r is at rest in a uniform magnetic field of magnitude B that extends far beyond the edge of the loop. The plane of the loop is parallel to the page and the magnetic field is directed perpendicular to and out of the page, as indicated by the blue dots. If the magnitude of the magnetic field is decreased at a rate of 1 T/s, what is true about the induced current in the copper loop
Answer:
i =[tex]- \frac{r \ A'}{2 \ rho}[/tex] , i = 0.92 A
Explanation:
This exercise asks for the electromotive force, which can be calculated with Faraday's law
fem = [tex]- \frac{d \Phi_B }{dt}[/tex]
where the magnetic flux
Ф = B. A
bold letters indicate vectors. We can write this equation
Ф = B A cos θ
In this case the magnetic field is perpendicular to the page and the normal to the loop of the loop is also parallel to the page, therefore the angle is zero and the cosine is 1
the loop is
A = π r²
we substitute in the first equation
fem = - π r² [tex]\frac{dB}{dt}[/tex]
we substitute the values
fem = -π r² 1
fem = - π r²
to calculate the current let's use ohm's law
V = i R
R = ρ L / A'
where A 'is the area of the wire and L is the length of the loop
L = 2π r
V = i (ρ 2π r / A ')
I = [tex]\frac{V \ A'}{2\pi \ r \ rho}[/tex]
In this case
V = fem
I = fem / R
i =[tex]- \frac{r \ A'}{2 \ rho}[/tex]
In order to complete the calculation, you need the radius of the loop and / or the wire cutter.
if we assume that the loop has a radius of r = 1 cm = 0.01 m and an area of the wire A'= π 10⁻⁶ m² a radius of the wire 1 mm
i = - 10⁻² π 10⁻⁶ / ( 2 1.7 10-8)
i = 0.92 A
A car horn creates a 595 Hz tone at rest. Two cars pass on the street, each going 20.0 m/s; the first car honks. What frequency does the other car hear before they pass each other?
Doppler frequency, the other car hear before they pass each other is 668.68 Hz.
What is frequency?Frequency is the number of occurrences of a repeating event per unit of time.
What is Doppler EFFECT?The Doppler effect is the change in frequency of a wave in relation to an observer who is moving relative to the wave source.
According to the Doppler Effect, the frequency observed is
[tex]fo=fs\frac{v+v_{o} }{v-v_{s} }[/tex]
[tex]f_{o}=595\frac{343+20 }{343-20 }\\f_{o} = 668.68 Hz[/tex]
To know more about Doppler Effect here
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Please help (I didn’t know what subject to put this in but it’s earth science)
A pulley system is made of 3 pulley write its velocity ratio
Almost 3 times fast than normal pulley system
mark me
mercury is commonly used in thermometer give reasons
Answer:
hi
BECAUSE MERCURY IS USED BECAUSE IT is the only liquid available in room temperatureExplanation:
pls mark as a BRAINLIST
Which solution has the greatest number of hydrogen ions?
blood, pH = 7.2
lemon juice, pH = 2
soda, pH = 3.5
bleach, pH = 13.5
Answer:
lemon
Explanation:
the lower the number the hier hydrogen ions
Answer: B
Explanation:
Give reason Pascal is a derived unit
Answer:
Pascal is a derived unit because it cannot be expressed in any physics terms, but it is an expression of fundamental quantities.
Explanation:
[tex]{ \sf{Pasacal \: ( Pa) = \frac{newtons}{metres {}^{2} } }} \\ \\ { \sf{Pasacal \: (Pa) = \frac{kg \times {ms}^{ - 2} }{ {m}^{2} } }}[/tex]
find the expression for the displacement covered in nth or in last one second
Answer:
Snth = u + a/2 ( 2n - 1)
Explanation:
Do you need explanation based on graph, integration or other method?
List two factors that compression force depends on
The magnitude (size or numerical value) and the direction.
Hope this helps!!! :)
A jet airplane is in level flight. The mass of the airplane is m=8950 kg. The airplane travels at a constant speed around a circular path of radius R=9.33 mi and makes one revolution every T=0.123 h. Given that the lift force acts perpendicularly upward from the plane defined by the wings, what is the magnitude of the lift force acting on the airplane?
Answer:
The net force is 91780.8 N.
Explanation:
mass, m = 8950 kg
Radius, R = 9.33 miles = 15015.2 m
Time, T = 0.123 h = 442.8 s
There are two forces acting on the plane.
Horizontal force is the centripetal force and the vertical force is the weight.
[tex]Fx =m R w^2\\\\Fx = m R \frac{4\pi^2}{T^2}\\\\Fx = 8950\times 15015.2\times \frac{4\times 3.14\times 3.14}{442.8\times 442.8}\\\\Fx = 27030.8 N \\\\Fy = m g \\\\ Fy = 8950\times 9.8 \\\\Fy = 87710 N[/tex]
The net force is
[tex]F = \sqrt{Fx^2 + Fy^2}\\\\F = \sqrt {27030.8^2 + 87710^2}\\\\F = 91780.8 N[/tex]
5. Tại sao khi lặn ta luôn cảm thấy tức ngực và càng lặn sâu thì cảm giác tức ngực càng tăng? A. Ap suất của nước giảm B. Ap suất không khí tăng C. Ap suất không khí giảm D. Ap suất của nước tăng
Answer:
c and d
Explanation:
obviously kksxsxksxkskxkskxksxksxsxsxsxsxsxsxs
Q2.
1.0 kg of ice at -10°C is added to 10 g of water at 0°C.
(a)
Find the final temperature of the mixture. (The specific latent heat of fusion of
ice is 336 J/g and the specific heat capacity of ice is 2000 J kg K-1)
Please help
Answer:
gsbddgshdhsghhdhdhvvs
a busis moving with the initial velocity 10m/s . after 4 seconds, the velocity becomes 30m/s . find the acceleration produce by bus,......please I need help
Answer:
5 m/s²
Explanation:
Use the acceleration formula: [tex]a=\frac{v_f-v_i}{t}[/tex]
a = acceleration (m/s²)vf = final velocity (m/s)vi = initial velocity (m/s)t = time (s)Based on the information given to us by the prompt, we know:
vi = 10 m/svf = 30 m/st = 4 sSubstitute these values for the variables to calculate the acceleration:
[tex]a=\frac{30-10}{4}\\\\a=\frac{20}{4}\\\\a=5[/tex]
Therefore, the acceleration of the bus is 5 m/s².
how is pressure and density related?
Answer:
Density is directly proportional to pressure
Explanation:
As pressure increases (with constant temperature), density also increases.
Density is inversely proportional to temperature.
how do atoms lose electrons ?
Answer:
Explanation:
By being close to an atom that will gladly take the electrons being offered.
Suppose you are talking about Be. It is in the second column. It has two outer electrons that can be given away. It will not give away one of the two remaining electrons because they are too close to the + nucleus.
Along comes a Fluorine atom. It has 7 electrons in its outer ring. The chemistry of the situation allows it to take on one of the two electrons Be is offering. It is all a matter of charges and attractions.
Another Fluorine atom will take on the remaining electron from the Be. The outer ring cannot take on more than 1 electron, but that is enough
In order to find the resultant of two vectors we must use the pythagoran therom, a +b2-2. Where the crepresents the resultant vector
Answer:
Furthermore, the Pythagorean theorem works when the two added vectors are at right angles to one another - such as for adding a north vector and an east vector.
9. Which of the following is NOT a recommendation to help you succeed in this course?
Consistently and actively work in the course on a daily basis.
Wait until the end of the semester to complete all work.
Complete all assignments in a timely manner.
Contact your instructor if you have questions.
Answer:
Wait until the end of the semester to complete all work.
Explanation:
this is the obvious answer.
please mark me brainliest
Answer:
Wait until the end of the semester to complete all work
Which of the following is an exa example of a wave
Longitudinal waves
Transverse waves
Electromagnetic Waves
Water waves
Rope waves
LIght Waves
Solve for M₂
Base Equation: M₂ = Fr²/GM₁
F = 132N, G = 6.67 x 10⁻¹¹ Nm²/kg², r = .243m, and M₁ = 1.175 x 10⁴ kg, then what is M₂ = ?
Explanation:
M₂ = Fr²/GM₁
M₂ = [(132N)(.243m)²]/[(6.67*10^-11N*m²/kg)(1.175*10^4kg)]
M₂ = (7.79N*m²)/(7.84*10^-7N*m²)
M₂ = 9.94*10^6 kg
If we increase the surface area of a given surface without changing the force acting on it, then the pressure acting on it will ______ (increase/decrease/remain the same)
Answer:
Decrease
Explanation:
The pressure is the force per unit area. So, P=F/A
Thus the pressure P is inversely proportional to contact area A.
So when area increases , the pressure will be decreasing.
Give reason.
b} String roller is an example of wheel and axel .Why?
Explanation:
string roller is called an example of wheel and axel because The thin rod which needs to be turned is called the axle and the wider object fixed to the axle, on which we apply force is called the wheel.
hence the we apply force on the roller and the string gets tight.
Joseph jogs from one end A to the other end B of a straight 300 m road in 2 minutes 30 seconds and then turns around and jogs 100 m back to point C in another 1 minute. What are Joseph's average speeds and velocities in jogging (a) from A to B and (b) from A to C?
Answer:
Explanation:
(a) It is given that Joseph jogs on a straight road of 300m in a time interval of 2 minutes and 30 seconds, which is equal to 150seconds. Therefore, when Joseph jogs from point A to point B, he covers a distance of 300m in time of 150seconds. Hence, his average speed is 300m/150s=2ms^−1. Since it is a straight road and he jogs in a single direction in this case, his displacement is equal to 300m. Since it is a straight road and he jogs in a single direction in this case, his displacement is equal to 300m.
Hence, his average velocity is 300m/150s=2ms^−1
(b) Then it is given that he turns back and points B and jogs on the same road but in the opposite direction for a time interval for 1 minute and covers a distance of 100m.If we consider the whole motion of Joseph, i.e. from point A to point C, then he covers a total distance of 300m+100m=400m. And he covers this total distance in a time interval of 2.5min+1min=3.5min=210s.
Therefore, his average speed for this journey is 400m210s=1.9ms−1.
For the same journey is displacement is equal to the distance between the points A and C,i.e. 300m−100m=200m.
Hence, his average velocity for this case is 200m/210s=0.95ms^−1
A rod is made up of copper and wood joined together.
After the rod is heated at the join in the centre for about a minute, where would the lowest temperature be?
my views
Explanation:
Figure (8) shows a rod made up of copper and wood joined together. The rod is heated at the joint in the centre for about a minute. At which point – A, B, C or D, would it show the lowest temperature? PLEASE GIVE REASONS ALSO(MINIMUM 2)
Ley de Charles-.
1) En un recipiente hermético se tiene 150 ml de una sustancia gaseosa, a una temperatura de 115°C, esto como resultado de una reacción. ¿Cuál sería su volumen inicial, cuando su temperatura era de 100°C?
2) Al inicio cuando la temperatura es de 200°C, se tienen 350 ml de un gas “Y”. ¿Qué volumen se obtendrá si la temperatura se incrementa a 250°C?
Tomando en cuenta la Ley de Charles y la condiciones dentro del recipiente, tenemos las siguientes conclusiones con respecto al volumen del recipiente:
1) El volumen inicial del gas es 144.203 mililitros.
2) El volumen final del gas es 386.986 mililitros.
La Ley de Charles establece que el Volumen de un gas es directamente proporcional a su Temperatura, basados en este hecho, podemos resolver los problemas en cuestión mediante la siguiente relación matematica:
[tex]\frac{V_{1}}{T_{1}} = \frac{V_{2}}{T_{2}}[/tex] (1)
Donde:
[tex]V_{1}[/tex] - Volumen inicial, en mililitros.
[tex]V_{2}[/tex] - Volumen final, en mililitros.
[tex]T_{1}[/tex] - Temperatura inicial, en Kelvin.
[tex]T_{2}[/tex] - Temperatura final, en Kelvin.
1) Si sabemos que [tex]V_{2} = 150\,mL[/tex], [tex]T_{2} = 388.15\,K[/tex] and [tex]T_{1} = 373.15\,K[/tex], entonces el volumen inicial del gas es:
[tex]V_{1} = \frac{T_{1}}{T_{2}}\times V_{2}[/tex]
[tex]V_{1} = \frac{373.15\,K}{388.15\,K}\times 150\,mL[/tex]
[tex]V_{1} = 144.203\,mL[/tex]
El volumen inicial del gas es 144.203 mililitros.
2) Si sabemos que [tex]T_{1} = 473.15\,K[/tex], [tex]V_{1} = 350\,mL[/tex] and [tex]T_{2} = 523.15\,K[/tex], entonces el volumen final del gas es:
[tex]V_{2} = \frac{T_{2}}{T_{1}}\times V_{1}[/tex]
[tex]V_{2} = \frac{523.15\,K}{473.15\,K}\cdot 350\,mL[/tex]
[tex]V_{2} = 386.986\,mL[/tex]
El volumen final del gas es 386.986 mililitros.
He aquí una pregunta relacionada con la Ley de Charles: https://brainly.com/question/21184611
please help me with my question I will like and mark as brainliest for the first correct answer due tomorrow morning
Answer:
1845.26 ?
Explanation:
18.46 × 99.96= 1845.2616 = 1845.26
im not entirely sure though
An observer is standing next to the tracks, watching a train approach. The train travels at 30 m/s and blows its whistle at 8,000 Hz as it approaches and then passes by the observer without slowing down. Assuming the speed of sound is 340 m/s, how much of a frequency change did the observer hear?
7351.35Hz
f0= v-Vo/v-Vs × FSA
= 340-0 /340+30 ×8000
= 340/370× 8000
= 7351.35hz
any person who opens the door he applies
Answer:
any person who opens the door he applies pulling force
Two stones are dropped from the edge of a 60m cliff , the second stone 1.6secon after the first . How far below the top of the cliff is the second stone when the separation between the two stone is 36m?
Answer:
The separation between the two stones is 36 m, when the second stone is approximately 10.9 m below the top of the cliff
Explanation:
The given parameters are;
The height of the cliff from which the stones are dropped, h = 60 m
The time at which the second stone is dropped = 1.6 seconds after the first
The distance below the top of the cliff when the distance between the two stones is 36 m = Required
We have;
The kinematic equation of motion that can be used is s = u·t - (1/2)·g·t²
For the first stone, we have, s₁ = u·t₁ - (1/2)·g·t₁²
For the second stone, we get; s₂ = u·t₂ - (1/2)·g·t₂²
t₁ = t₂ + 1.6
g = The acceleration due to gravity ≈ 9.81 m/s²
s = The distance below the cliff top
The initial velocity of the stones, u = 0
Let t represent the time from which the second stone is dropped at which the distance between the two stones is 36 m, we have;
s₁ = u·(t + 1.6) + (1/2)·g·(t + 1.6)²
s₂ = u·t + (1/2)·g·t²
u = 0
∴ s₁ - s₂ = 36 = (1/2)·g·(t + 1.6)² - (1/2)·g·t²
2 × 36/(g) = (t + 1.6)² - t² = t² + 3.2·t + 2.56 - t² = 3.2·t + 2.56
2 × 36/(9.81) = 3.2·t + 2.56
t = (2 × 36/(9.81) - 2.56)/3.2 = ≈ 1.49 s
t ≈ 1.49 s
s₂ = (1/2)·g·t²
∴ s₂ = (1/2) × 9.81 × 1.49² ≈ 10.9
The distance below the top of the cliff of the second stone when the the separation between the two stones is 36 m, s₂ ≈ 10.9 m.
A person has power of 550 watt. What does it mean?
Answer:
It means that person can do work or can posses energy at a rate of 550 watts.
Or : can posses energy of 550 joules in one second.
Explanation:
[tex]{ \bf{power = \frac{work}{time} }}[/tex]
