Answer:
A) I_laser = 70.74 W/m²
B) I_bulb = 1.989 W/m²
C) it is not advisable to look at the laser beam directly.
Explanation:
We are given;
Power; P = 0.50 mW = 0.5 × 10^(-3) W
Diameter; d = 3 mm = 0.003 m
Radius; r = d/2 = 0.003/2 = 0.0015 m
A) Area of beam; A = πr²
A = 0.0015²π
Now, formula for average intensity is;
I = P/A
I = (0.5 × 10^(-3))/0.0015²π
I = 70.74 W/m²
B) We are told to find the intensity of a lightbulb producing 100-W.
Thus, P = 100 W
A light bulb is spherical in shape. Thus;
Area; A = 4πr²
We are told it's 2 m away.
Thus; r = 2 m
A = 4π(2)²
A = 16π
Thus, I = P/A = 100/16π
I = 1.989 W/m²
C) The intensity of the laser beam is far greater than that of the light bulb. Thus, it is not advisable to look at the laser beam directly.
Một mạch kín hình vuông cạnh 20cm đặt vuông góc với 1 từ trường đều có độ lớn thay đổi theo thời gian. Trong khoảng thời gian 0,01s , cho độ lớn cảm ứng từ tăng đều từ 0 lên đến 0,05T. Biết điện trở của mạch là 0,5. Tính cường độ dòng điện cảm ứng trong mạch
Answer:
please do write it in english
What would be the acceleration in a body moving with uniform velocity and why?
Explanation:
The derivative of a constant term is always 0. So the acceleration of the body would be zero. Hence, the acceleration of a body moving with uniform velocity will always be zero.
hope it helps you
. A radio station transmitting at a frequency of 200KH, emits waves of wavelength 1.5 km.the velocity of the radio waves is
Answer:
Explanation: as,
v=f∧
v=200×10³×1.5×10³
v=2.7×10^7ms⁻¹
The velocity of the radio waves is 3 × 10⁸ ms⁻¹.
A radio station frequency = 200 KH
wavelength = 1.5 km
How the velocity of the radio waves are calculated?Radio waves in the electromagnetic spectrum has the longest wavelength and it will always be below 300GHz. The radio waves can be generated with acceleration through some charged particles. Only through the transmitter via antenna the radio waves can gets transmitted. Radio waves can be used in all the electronic devices as mobile phones, radio communication, radars and navigations.
V = f λ
Velocity, v = ( 200 × 10³ ) × ( 1.5 × 10³ )
= ( 300 × 10⁶ )
v = 3 × 10⁸ ms⁻¹.
Hence, the velocity of the radio waves is 3 × 10⁸ ms⁻¹.
Learn more about the radio waves,
https://brainly.com/question/21995826
#SPJ2
Which of the following can be correct units for acceleration?
A. miles/hr/m
B. Km/s/hr
C. m/s/m
D. km/m/s
Answer:
B. Km/s/hr
Explanation:
Một con lắc lò xo gồm 1 quả nặng có m= 0,2kg treo vào lò xo có độ cứng k= 100N/m, cho vật dao động điều hoà theo phương thẳng đứng với biên độ A= 1,5 cm. Lực đàn hồi cực đại có giá trị
Write the dimension of a / b in the x = at + bt2. Where x is the distance and t is the time?
The dimension of a/b where x is the distance and t is the time is T
Given the expression
x = at + bt²
where
x is the distance
t is the time
Based on the homogeneity principle, the expression on the left-hand side must be equal to that on the right. Hence;
x = at
[tex]a = \frac{x}{t}[/tex]
Since x is the distance and distance is measured in metres, the dimension equivalent will be the length 'L'
Since t is the time and time is measured in seconds, the dimension equivalent will be the seconds 'T'
[tex]a=\frac{L}{T}[/tex]
Similarly;
x = bt²
[tex]b=\frac{x}{t^2}\\b=\frac{L}{T^2}[/tex]
Next is to get a/b;
[tex]\frac{a}{b} = \frac{L}{T} \div \frac{L}{T^2}\\\frac{a}{b} = \frac{L}{T}*\frac{T^2}{L} \\\frac{a}{b} =\frac{T^2}{T}\\\frac{a}{b} =T[/tex]
Hence the dimension of a/b is T
Un auto se desplaza por una carretera recta a una velocidad de 85 km/h. Al cabo de 2 horas, ¿qué distancia habrá recorrido, en metros?
Answer:
Distancia, D = 170,000 metros
Explanation:
Dados los siguientes datos;
Velocidad = 85 km/h Tiempo = 2 horasPara encontrar la distancia recorrida, en metros;
Matemáticamente, la distancia recorrida por un objeto se calcula mediante la fórmula;
Distancia = velocidad * tiempo
Sustituyendo los valores en la fórmula, tenemos;
Distancia = 85 * 2
Distancia = 170 kilómetros
A continuación, convertiríamos el valor en kilómetros a metros;
Conversión:
1 kilómetros = 1000 metros
170 kilómetros = D metros
Multiplicación cruzada, tenemos;
D = 170 * 1000
D = 170,000 metros
Por lo tanto, habría viajado 170,000 metros después de 2 horas.
sort out electric current as fundamental or derived unit.
Answer:
electric current is derived unit.
Explanation:
According to the definition of electric current, it appears to be a derived quantity. Charge on the other hand seems more fundamental than electric current.
how can we maintain peace in the nature and surrounding
Answer:
6 Ways To Promote Peace
Treat all people with kindness, regardless of race, gender orientation, sexual orientation, religion, etc.
Attend a peace rally.
Write to your government (local and federal)
Create a peaceful affirmation/mantra.
Don't engage in violence of any kind.
Don't purchase weapons.
A 250g object hangs from a spring that has a spring constant of 48.0 N/m and oscillates with an amplitude of 5.42cm
1)The magnitude of the objects acceleration when the displacement is 4.27 cm (down) is __ m/s^2
2)Given that the object has an amplitude of 5.42 cm the maximum speed that the object is __m/s
Explanation:
Given that,
Mass of an object, m = 250 g = 0.25 kg
Spring constant, k = 48 N/m
The amplitude of the oscillation, A = 5.42 cm = 0.0542 m
1. At equilibrium,
ma = kx
Where
a is the acceleration of the object
So,
[tex]a=\dfrac{kx}{m}\\\\a=\dfrac{48\times 0.0542}{0.25}\\\\a=10.4\ m/s^2[/tex]
2. The maximum speed of the object is :
[tex]v=A\omega\\\\v=A\sqrt{\dfrac{k}{m}}\\\\v=0.0542\times \sqrt{\dfrac{48}{0.25}}\\\\v=0.75\ m/s[/tex]
Hence, this is the required solution.
the force between the earth and the body which is at a distance r from the center of the earth is F. What must be this distance for the force to be doubled.
Answer:
Explanation:
The gravitational force between the earth and another body is F = -GM_em/r^2 r where G = 6.67 times 10^-11 Nm^2/kg^2 is the gravitational constant, M_e = 5.97 times 10^24 kg is the mass of the earth, m is the mass of the other body, and r is the position vector of the second body with respect to the centre of the earth.
Calculate the efficiency of the following appliances:
1. A radiator that converts 1000) of electrical energy into 900J
of heat energy and 100J of light energy
2. A torch that converts 100J of chemical energy into 35) of
light energy and 65J of heat energy
3. A car that converts 10,000J of chemical energy into 6000) of
kinetic energy and 4000J of heat energy.
4. An energy saver light converts 1,000J of electrical energy
into 7003 of light energy and 300J of heat energy.
5. A speaker converts 100J of electrical energy into 50J of
sound energy and 50J of heat and kinetic energy.
we
Answer:
1. The efficiency of the radiator is 90 %
2. The efficiency of the torch is 65 %
3. The efficiency of the car is 40 %
4. The efficiency of the energy saver is 70 %
5. The efficiency of the speaker is 50 %
Explanation:
Efficiency = (Useful energy out ÷ Total energy in) × 100 J
1. Useful energy = 900 J
The total energy in = 1000 J
The efficiency of the radiator = ((900 J)/(1,000 J)) × 100 % = 90 %
2. Useful energy = 65 J
The total energy in = 100 J
The efficiency of the torch = ((65 J)/(100 J)) × 100 % = 65 %
3. Useful energy = 4,000 J
The total energy in = 10,000 J
The efficiency of the car = ((4,000 J)/(10,000 J)) × 100 % = 40 %
4. Useful energy = 700 J
The total energy in = 1,000 J
The efficiency of the energy saver = ((700 J)/(1,000 J)) × 100 % = 70 %
5. Useful energy = 50 J
The total energy in = 100 J
The efficiency of the speaker = ((50 J)/(100 J)) × 100 % = 50 %
Can acceleration and velocity be equal vectors?
Answer:
Velocity is the rate of change of position with respect to time, whereas acceleration is the rate of change of velocity. Both are vector quantities (and so also have a specified direction), but the units of velocity are meters per second while the units of acceleration are meters per second squared.
solve two questions under inclined plane using Newton 2nd law
Explanation:
If the mass of the inclined plane is large enough, could N ever be equal to mgcosθ. Reasons?
So far I've come up with: mgcosθ−N=ma meaning if N were to equal mgcosθ, ma=0. Since the surfaces are frictionless and since N is acting on the inclined plane too(it'll have a horizontal component), this isn't possible. Am I right? Where am I going wrong?
importance of measurement in our dairy life
Answer:
in order to know the length of something
Write down the conservation of momentum?
In a Rutherford scattering experiment, alpha parti- cles having kinetic energy of 7.70 MeV are fired toward a gold nucleus that remains at rest during the collision. The alpha particles come as close as 29.5 fm to the gold nucleus before turning around. (a) Calculate the de Broglie wave- length for the 7.70-MeV alpha particle and compare it with the distance of closest approach, 29.5 fm. (b) Based on this comparison, why is it proper to treat the alpha particle as a particle and not as a wave in the Rutherford scattering experiment
(a) The de Broglie wavelength is approximately 5.175 × 10⁻¹⁵ meters. The wavelength is lesser than the distance of closest approach
(b) It is proper to treat the alpha particle as a particle and not as wave because the distance of closest approach is much larger than and not comparable to its wavelength for the alpha particle for the alpha particle to be treated as a wave
The given parameters are;
The kinetic energy of the alpha particles = 7.70 MeV = 1.23368 × 10⁻¹² J
The distance from the gold nucleus the alpha particles reach = 29.5 fm
(a) The de Broglie wavelength of a particle is given as follows;
[tex]\mathbf{\lambda = \dfrac{h}{p}}[/tex]
Where;
λ = The wavelength
h = Planck's constant = 6.62607004 × 10⁻³⁴ m²·kg/s
p = The momentum of the particle = Mass of an electron, m × Velocity, v
The mass of an alpha particle, m ≈ 6.645 × 10⁻²⁷ kg
Therefore;
[tex]\lambda = \dfrac{h}{m \times v}[/tex]
The kinetic energy of the alpha particle, K.E. = (1/2)·m·v²
∴ v = √(2 × K.E./m)
Therefore;
[tex]\lambda = \dfrac{h}{m \times \sqrt{2 \times \dfrac{K.E.}{m} } } = \dfrac{h}{ \sqrt{2 \times m \times K.E.} }[/tex]
Plugging in the values of the variables gives;
[tex]\lambda = \dfrac{6.62607004 \times 10 ^{-34} }{ \sqrt{2 \times 6.645 \times 10 ^{-27} \times 1.23368 \times 10^{-12} } } \approx 5.175 \times 10^{-15}[/tex]
The de Broglie wavelength of the alpha particle, λ ≈ 5.175 × 10⁻¹⁵ m
The distance of closest approach = 29.5 fm = 29.5 × 10⁻¹⁵ m
Compared to the distance of closest approach, the wavelength of the alpha particle is lesser than the distance of closest approach
(b) Given that the distance of closest approach is six times larger than the wavelength of the alpha particle, and alpha particle behaving as waves are expected to approach closer to the gold nucleus in the region of their wavelength before deflection, therefore, the larger distance of closest approach is indicative of a charged particle to charged particle interaction, and therefore, particle behavior of alpha particles.
Learn more about de Broglie wavelength, particles and wave behavior of radiation here;
https://brainly.com/question/22471405
https://brainly.com/question/17403491
https://brainly.com/question/15128575
84. Three resitors each of value 30 respectively are connected in a parallel
combination across a 10 V battery the current through each resitor is
Answer:
each resistor draws 1/3 of an amp or 0.33333 amps
Explanation:
V = I * R
V = 10 volts
R = 30 ohms
10 = I * 30 Divide by 30
10/30 = I
I = 0.33333
Si dejamos caer un objeto desde una gran altura, ¿será que tiene siempre la misma velocidad
Answer:
asdiieiwihebebwiwo3o2iwjw3
Make a tree diagram based on the topic motion which includes all the concept like uniform & non uniform motion accelerated motion equation of motion motion etc
I think it is a education tips
Why are road accidents at high speeds very much worse than road accidents at low speeds?
Answer:
The momentum makes it worse.
Explanation:
The momentum of vehicles running at faster speeds is very high and causes a lot of damage to the vehicles.
What is Plancks Constant? Need it ASAP
Answer:
The Planck constant, or Planck's constant, is a fundamental physical constant denoted h, and is of fundamental importance in quantum mechanics. A photon's energy is equal to its frequency multiplied by the Planck constant. Due to mass–energy equivalence, the Planck constant also relates mass to frequency.
Theory:Planck postulated that the energy of light is proportional to the frequency, and the constant that relates them is known as Planck's constant (h). His work led to Albert Einstein determining that light exists in discrete quanta of energy, or photons.
E = hf
[tex] \sf \: h = 6.626 \times {10}^{ - 34} \: kg \: {m}^{2} {s}^{ - 1} [/tex]
define mass defect and binding energy
Answer:
About Transcript. Nuclear binding energy is the energy required to split an atom's nucleus into protons and neutrons. Mass defect is the difference between the predicted mass and the actual mass of an atom's nucleus. The binding energy of a system can appear as extra mass, which accounts for this difference.
Explanation:
PLZ MARK AS THE BRAINLIEST
I NEED IT URGENTLY
HAVE A GOOD DAY
MAY GOD BLESS U
: )
An aluminium block of mass 1 kg is heated by an electric heater for 3 minutes and a temperature rise of 15 °C is recorded. If the electric heater is connected to a voltmeter which gives a reading of 30 V and an ammeter which gives a reading of 2.5 A, calculate the specific heat capacity of the aluminium.
Answer:
the specific heat capa city of the aluminium is 900 joules per kilogram per °C.
Am I right please?
For problems 2-3, a Ferrari accelerates from 0-60.0 miles per hour in 2.50 seconds.
2. What is its final speed, in m/s?
a 5.6 m/s
b. 13 m/s
c. 26.8 m/s
d. 1608 m/s
0-60.0 per near
2.50 seconds
3. What is its average acceleration?
a. 24.0 m/s
b. 10.7 m/s2
c. 38.6 m/s2
d. 13 m/s
Answer:
Explanation:
The first part of this question is simply asking us to convert the speed from miles per hour to meters per second:
[tex]60.0\frac{mi}{hr}*\frac{1hr}{3600sec}*\frac{1609.34m}{1mi}=26.8\frac{m}{s}[/tex] choice C.
The next part wants us to use the equation for acceleration and find the acceleration:
[tex]a=\frac{v-v_0}{t}[/tex] where v is final velocity, v0 is initial velocity, and t is time in seconds (which was one of the reasons we had to convert the initial velocity from 60.0 mph to m/s):
[tex]a=\frac{26.8-0}{2.5}[/tex] and
a = 10.7 m/s/s, choice B.
Group elements number 11 to 20 as either metallic, non metallic or metalloid.
Answer:
The elements are grouped into the different substances by color. As you can see, Lithium, Beryllium, Sodium, Magnesium, Aluminum, Potassium, and Calcium are metals out of the first 20 elements.
Hydrogen, Helium, Carbon, Nitrogen, Oxygen, Fluorine, Neon, Phosphorus, Sulfur, Chlorine, and Argon, are non-metals within the first 20 elements.
Boron and Silicon count as Metalloids in the Periodic Table (properties of both metals and non-metals)
reference- socatric q and a
Explanation:
Answer:
(11-13) - Metals
(14) - Metalloid
(15-18) - Non- metals
(19-20) - Metals
Explanation:
The elements from 11 to 13 are metals. They are Sodium(Na), Magnesium(Mg) and Aluminum(Al) respectively.
The element 14 is a metalloid. It’s Silicon(Si).
The elements from 15 to 18 are non metals. The 18th element is a noble gas known as Argon(Ar).
The elements from 15 to 17 are Phosphorus(P), Sulphur(S) and Chlorine(Cl).
The elements from 19 to 20 are metals. They are Potassium(K) and Calcium(Ca).
Assuming Faraday constant to be 96500c/mol and relative atomic mass of copper 63,calculate the mass of copper liberated by 2A current in 5min.ans 0.196gm
Answer: The mass of copper liberated is 0.196 g.
Explanation:
The oxidation half-reaction of copper follows:
[tex]Cu\rightarrow Cu^{2+}+2e^-[/tex]
Calculating the theoretical mass deposited by using Faraday's law, which is:
[tex]m=\frac{M\times I\times t(s)}{n\times F}[/tex] ......(1)
where,
m = actual mass deposited = ? g
M = molar mass of metal = 63 g/mol
I = average current = 2 A
t = time period in seconds = 5 min = 300 s (Conversion factor: 1 min = 60 sec)
n = number of electrons exchanged = 2
F = Faraday's constant = 96500 C/mol
Putting values in equation 1, we get:
[tex]m=\frac{63 g/mol\times 2A\times 300s}{2\times 96500 C/mol}\\\\m=0.196g[/tex]
Hence, the mass of copper liberated is 0.196 g.
what is the relation between centre of gravity and stability
Explanation:
tilting it will raise the height of its center of gravity.
can anyone help me with this one
Answer:
c) sin c /sin d
because light is moving from denser to shallower medium
b) refraction of light
Explanation:
Using your Periodic Table, which element below has the smallest atomic radius? A.) Sodium, B.) Chlorine, C.) Phosphorus, D.) Iron
Chlorine has the smallest atomic radius since the atomic radius decreases as you travel to the right and up
