Answer:
f = 7.9487 10¹³ Hz
Explanation:
The photoelectric effect was correctly explained by Einstein assuming that the radiation is composed of photons, which behave like particles.
hf = K + Ф
It indicates the frequency and the kinetic energy, let's look for the work function
Ф = hf - K
let's reduce the magnitudes to the SI system
K = 0.332 eV (1.6 10⁻¹⁹ J / 1 eV) = 0.5312 10⁻⁻¹⁹ J
let's calculate
Ф = 6.63 10⁻⁻³⁴ 6.64 10¹¹ - 0.5312 10⁻¹⁹
Ф = 4.40 10⁻²² - 0.5312 10⁻¹⁹
Ф = 5.27 10⁻²⁰ J
for the minimum frequency that produces photoelectrons, the kinetic energy is zero
hf = Ф
f = Ф / h
f = 5.27 10⁻²⁰ / 6.63 10⁻³⁴
f = 7.9487 10¹³ Hz
Prominences and sunspots are both:
A. Jets of burning gas
B. Patches on the Sun's surface
C. Influenced by the Sun's electromagnetic field
D. Visible during an eclipse
Answer:
C. Influenced by the Sun's electromagnetic field
Explanation:
"Sunspots occur in pairs because each is one side of a loop of the Sun's magnetic field that reaches the Sun's surface. Solar prominences are the plasma loops that connect two sunspots."
An 8.20 kg object is pulled along a horizontal surface by a force of 22.0 N. If its acceleration is 1.1 m/s2, what is the coefficient of friction between the two surfaces?
Answer:
0.5
Explanation:
In this picture,
The Mississippi River is continually forming and changing the land mass in the southern part of Louisiana. This kind of build up of land is called a
Answer:
dfdfsdf s
Explanation:
fsdfsd fsd fds f vsdvads
please help asap
Ms. Brando’s students are studying forces. She has assigned a fun task: designing a balloon car. The students must design a car and see which model will travel the greatest distance. The basic design of the cars can be seen here. First the balloon is inflated and attached to the car. It is important to keep the balloon closed. Once attached to the car, the stem of the balloon is opened and air rushes out through the straw. The air goes one way; the car moves in the other direction. There are no restrictions on the design other than the students must use the materials given to them by Ms. Brando. What is the source of the force that moves the car? A) The circumference of the balloons. B) The friction between the wheels and the track surface. C) The air rushing out of the balloon through the straw. D) The mass of the car: the lighter the car the farther it moves.
Answer: a
Explanation:
when a car dives on a road it a makes friction but it need something to push it or start it which is the balloon in this example
(sorry if im wrong)
In this image of an atom, what does the outer area consisting of tiny blue
dots represent?
O A. The electron cloud
B. Protons
C. The nucleus
D. Neutrons
Does gravity increase or decrease with greater mass???
Answer:
Increase
As the mass of either object increases, the force of gravitational attraction between them also increases.
Explanation:
The gravitational force is directly proportional to the mass of both interacting objects, more massive objects will attract each other with a greater gravitational force.
As the mass of either object increases, the force of gravitational attraction between them also increases.
Answered by none other than the ONE & ONLY #QUEEN herself aka #DRIPPQUEENMO
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Which of these is one of the five determinants of health?
A. The gender of your doctor
B. Your access to health services
C. The type of sport you play
D. The amount
your insurance deductible
Answer:
B
Explanation:
There is a bottleneck in producing masses higher than4He, because there are no mass-5or mass-8 stable nuclides. For older stars with high densities and high temperatures (T>100 million K), three alpha particles can form12C. This occurs by two alpha particles firstforming8Be, and then8Be reacting with another alpha particle to form12C before8Be candecay back to two alpha particles.a) Explain why this can only happen in very hot stars and high density.b) Calculate how much energy is given up when three alpha particles form12C.
Answer:
Explanation:
a)
To pass the Coulomb barriers and undergo nuclear fusion, alpha particles must be burned at high temperatures. As a result, the ignition temperature needed for this reaction is 5.4168 × 10¹⁰ K. Helium must be burned at a high temperature and density. As a result, this must occur for hot stars with high densities.
b)
The amount of energy given up can be calculated as follows:
[tex]_2He^4 + _2He^4 \to _4Be^8 ---- (1) \\ \\ _4Be^8 + 2_He^4 \to _6C^{12} ---(2)[/tex]
where;
[tex]M(_2He^4) = 4.002603 \ u \\ \\ M(_4Be^8) = 8.005305 10 \ u[/tex]
Therefore, from the reaction (1);
[tex]Q = \Big ( M(_2He^4) + M(_2He^4) - M(_4Be^8) \Big ) ( 931.5 \ MeV) \\ \\ = \Big ( 2(4.002603 \ u) - (8.00530510 \ u) \Big) \Big ( 931.5 \ MeV/u \Big) \ \\ \mathbf{= -0.092 \ MeV}[/tex]
From the second reaction:
[tex]Q = \Big ( M(_4Be^8) + M(_2He^4) - M(_6C^{12}) \Big ) ( 931.5 \ MeV) \\ \\ = \Big ( 8.00530510 \ u +4.002603 \ u -12 \ u \Big) \Big ( 931.5 \ MeV/u \Big) \ \\ \mathbf{= 7.37 \ MeV}[/tex]
A ladder 5.0 m long leans against a wall inside a spaceship. From the point of view of a person on the ship, the base of the ladder is 3.0 m from the wall, and the top of the ladder is 4.0 m above the floor. The spaceship moves past the Earth with a speed of 0.90c in a direction parallel to the floor of the ship. Find the angle the ladder makes with the floor as seen by an observer on Earth
Answer:
the angle the ladder makes with the floor as seen by an observer on Earth is 71.9°
Explanation:
Given the data in the question and as illustrated in the diagram below.
speed of the ship v = 0.90c
base of the ladder from the wall x₀ = 3.0 m
top of the later above the floor y = 4.0 m
we determine angle θ.
from the diagram,
tanθ = y/x₀
tanθ = y / x₀√( 1 - v²/c² )
we substitute
tanθ = 4.0 / 3.0√( 1 - ((0.9c)²/c²) )
tanθ = 4.0 / 3.0√( 1 - ((0.9²)c²/c²) )
tanθ = 4.0 / 3.0√( 1 - (0.9²) )
tanθ = 4.0 / 3.0√( 1 - 0.81 )
tanθ = 4.0 / 3.0√0.19
tanθ = 4.0 / 1.30766968
tanθ = 3.058876
θ = tan⁻¹( 3.058876 )
θ = 71.8965 ≈ 71.9°
Therefore, the angle the ladder makes with the floor as seen by an observer on Earth is 71.9°
What structure is represented by the letter
C?
PLEASE HELP!!!!!
Choose 1 answer:
А
Lysosome
B
Nucleus
C
Vacuole
D
Mitochondria
The drawing shows four sheets of polarizing material, each with its transmission axis oriented differently. Light that is polarized in the vertical direction is incident from the left and has an average intensity of 20 W/m2. Determine the average intensity of the light that emerges on the right in the drawing (a) when sheet A alone is removed, (b) when sheet B alone is removed, (c) when sheet C alone is removed, and (d) when sheet D alone is removed.
Answer:
Explanation:
At the point when light is vertically polarized is incident on the polarizer whose axes are situated at angle points [tex]\theta _1 , \theta _2 , \theta _3[/tex] the intensity power in the wake of going through all the polarisers is given by the Malus law, applied threefold for every one of the three axes.
[tex]I = I_o \ cos \theta _1 \ cos \theta _2 \ cos \theta _ 3[/tex]
The heading of the direction of the polarization is equivalent to the pivoted axes of the polarizer provided that light is an electromagnetic wave, its course of polarization is therefore controlled by the electric field part.
∴
a)
When sheet A is removed, the transmitted light goes through B, at 30°.
[tex]I = I_o \ cos ^2 \theta _1 \ cos ^2 \theta _2 \ cos^2 \theta _3[/tex]
[tex]I = 20 \ cos ^2 30 \ cos ^2 60 \ cos ^2 30[/tex]
[tex]I = 2.81 \ W/m^2[/tex]
b)
When B is removed, No light passes since the axis of A and the axis of C are perpendicular to each other.
c)
When C is removed, the intensity is indeed zero since the axes are aligned and adjusted at 90° to one another.
[tex]\mathbf{d) \ I - I_o cos^2 (0) cos^2 (30) \ cos^2 (60)}[/tex]
[tex]\mathbf{d = 3.75 \ W/m^2}[/tex]
what is a black whole why does it exist
Answer:
A black hole is a region of spacetime where gravity is so strong that nothing—no particles or even electromagnetic radiation such as light—can escape from it. The theory of general relativity predicts that a sufficiently compact mass can deform spacetime to form a black hole.
A baby was born on his due date, but doctors determined that a valve in his heart was too short to adequately pump blood to his body. The baby passed away after eight months. Which best describes the cause of his death?
He had a congenital condition.
He was premature.
He died in an accident.
He suffered SIDS.
Answer:
He had a cogenital condition
Explanation:
cogenital conditions are present before or at the time of birth and are considered birth defects
Answer:
The answer is C- He had a congential condition.
Explanation:
Edge
Two electrostatic point charges of +62.0 µC
and +43.0 µC exert a repulsive force on each
other of 189 N.
What is the distance between the two
charges? The value of the Coulomb constant
is 8.98755 × 109 N · m2
/C
2
.
Answer in units of m.
Select the correct answer.
Which type of energy is thermal energy a form of
two automobiles a and b are travelling in the same direction in adjacent lanes are stopped at a traffic signal. as the signal turns green, automobile a accelerates at a constant rate of 2 m/s2. two seconds later, automobile b starts and accelerates at a constant rate of 3.6 m/s2. determine (a) when b will overtake a, (b) the speed of each automobile at that time, and c) the location where b overtakes a relative to the traffic signal. -truck
Answer:
a.5.85 s b i. 15.7 m/s ii. 21.1m/s c. 61.62 m
Explanation:
(a) when b will overtake a,
Using s = ut + 1/2at² we express the distance moved by each automobile.
Since both automobiles start at rest, their initial speed, u = 0 m/s, a = acceleration of automobile and t = time of travel or overtaking
So s = 0 × t + 1/2at²
s = 0 + 1/2at²
s = 1/2at²
Let time, t be the time the automobile b start, and its acceleration a = 3.6 m/s²
So, s = 1/2 × 3.6 m/s² × t² = 1.8t²
Since automobile a starts 2 seconds earlier, its time of travel is (t + 2) s. Since its acceleration, a = 2 m/s²,
s = 1/2 × 2 m/s² × (t + 2)²
s = (t + 2)²
Since both distances are equal at overtaking
(t + 2)² = 1.8t²
t² + 4t + 4 = 1.8t²
1.8t²- t² - 4t - 4 = 0
0.8t² - 4t - 4 = 0
dividing through by 0.8, we have
0.8t²/0.8 - 4t/0.8 - 4/0.8 = 0
t² - 5t - 5 = 0
Using the quadratic formula to find t,
[tex]t = \frac{-(-5) +/-\sqrt{(-5)^{2} - 4 X 1 X (-5)} )}{2 X 1} \\t = \frac{5 +/-\sqrt{25 + 20} )}{2} \\t = \frac{5 +/-\sqrt{45} )}{2} \\t = \frac{5 +\sqrt{45} )}{2} or \frac{5 -\sqrt{45} )}{2}\\t = \frac{5 + 6.708 )}{2} or \frac{5 - 6.708)}{2}\\t = \frac{11.708 )}{2} or \frac{-1.708}{2}\\t = 5.854 sor -0.854 s[/tex]
t ≅ 5.85 or -0.85
We take the positive answer since t cannot be negative.
So, t = 5.85 s
So, b will overtake a 5.85 s later.
(b) the speed of each automobile at that time,
Using v = u + at for each automobile, where u =initial speed of automobile = 0 m/s (since they both start from rest), a = acceleration of automobile and t = time of travel of automobile
i. Speed of automobile a
For automobile a, its time of travel is (t + 2) s = 5.85 s + 2 s = 7.85 s and its acceleration is 2 m/s²
So, v = u + at
= 0 m/s + 2 m/s² × 7.85 s
= 0 m/s + 15.7 m/s
= 15.7 m/s
ii. Speed of automobile b
For automobile a, its time of travel is t s = 5.85 s and its acceleration is 3.6 m/s²
So, v = u + at
= 0 m/s + 3.6 m/s² × 5.85 s
= 0 m/s + 15.7 m/s
= 21.06 m/s
≅ 21.1 m/s
c) the location where b overtakes a relative to the traffic signal. -truck
The location where b overtakes a relative to the traffic signal is the distance each automobile moves before overtaking. In section (a), we foundthat distance s = 1/2at² = (t + 2)² = 1.8t²
Using s = (t + 2)²
= (5.85 + 2)²
= 7.85²
= 61.6225 m
≅ 61.62 m
1.Calculate the energy transferred by a 12V hairdryer, running on a current of 0.50A, that is left on for 8.0 minutes.
2. f 4 coulombs of charge flows in the circuit with a p.d. of 15V. Calculate the total energy transferred.
3. A 6.0 V battery passes a current of 1.0 A through a lamp for 2 minutes. How much charge passed through the lamp.
Answer:
1. Energy = 2880 Joules.
2. Energy = 60 Joules.
3. Quantity of charge = 120 Coulombs.
Explanation:
Given the following data;
1. Voltage = 12 Volts
Current = 0.5 Amps
Time, t = 8 mins to seconds = 8 * 60 = 480 seconds
To find the energy;
Power = current * voltage
Power = 12 * 0.5
Power = 6 Watts
Next, we find the energy transferred;
Energy = power * time
Energy = 6 * 480
Energy = 2880 Joules
2. Charge, Q = 4 coulombs
Potential difference, p.d = 15V
To find the total energy transferred;
Energy = Q * p.d
Energy = 4 * 15
Energy = 60 Joules
3. Voltage = 6 Volts
Current = 1 Amps
Time = 2 minutes to seconds = 2 * 60 = 120 seconds
To find the quantity of charge;
Quantity of charge = current * time
Quantity of charge = 1 * 120
Quantity of charge = 120 Coulombs
A piece of wood that floats on water has a mass of 0.0175 kg. A lead sinker is tied to the wood, and the apparent mass with the wood in air and the lead sinker submerged in water is 0.0765 kg. The apparent mass with both the wood and the sinker both submerged in water is 0.0452 kg. What is the SG of the wood
Answer:
The specific gravity of the wood is 1.56
Explanation:
Given;
mass of the wood in water, [tex]M_w_{H_2O}[/tex] = 0.0175 kg
apparent mass of the wood and lead sinker submerged in water, [tex]M_w_{(air)} + M_s_{H_2O}[/tex] = 0.0765 kg
apparent mass with both the wood and the sinker both submerged in water, [tex]M_w_{H_2O} + M_s_{H_2O} = 0.0452 \ kg[/tex]
Mass of the lead sinker alone submerged in water;
[tex]M_w_{H_2O} + M_s_{H_2O} = 0.0452 \ kg\\\\0.0175 \ kg + M_s_{H_2O} = 0.0452 \ kg\\\\M_s_{H_2O} = 0.0452 \ kg - 0.0175 \ kg\\\\M_s_{H_2O} = 0.0277 \ kg[/tex]
Mass of the wood in the air;
[tex]M_w_{(air)} + M_s_{H_2O} = 0.0765 \ kg\\\\M_w_{(air)} + 0.0277 \ kg = 0.0765 \ kg\\\\M_w_{(air)} = 0.0765 \ kg - 0.0277 \ kg\\\\M_w_{(air)} = 0.0488 \ kg[/tex]
Mass of water is calculated as follows;
[tex]M_w_{(air)} - M_w_{H_2O} = M_{H_2O}\\\\0.0488 \ kg - 0.0175 \ kg = M_{H_2O}\\\\0.0313 \ kg = M_{H_2O}[/tex]
The specific gravity of the wood is calculated as follows;
[tex]Specific \ gravity\ (S.G) \ of \ wood = \frac{mass \ of \ wood\ in \ air }{mass \ of \ water} \\\\Specific \ gravity\ (S.G) \ of \ wood = \frac{0.0488}{0.0313} \\\\Specific \ gravity\ (S.G) \ of \ wood = 1.559 = 1.56[/tex]
Therefore, the specific gravity of the wood is 1.56
Due to the earth's rotation, a person would be traveling faster at the equator than they would at a position halfway from the equator to the North Pole.
Answer:
False
Explanation:
It is actually the exact opposite.
Answer:
True.
Explanation:
Because the Earth's rotation causes it to bulge at the equator, the circumference of the Earth is greatest at the equator. This means that a person at the equator would have to travel a greater distance in a given amount of time than a person at a position closer to the poles. Therefore, a person at the equator would be traveling faster than a person at a position closer to the poles.
Why do you think geologists were able to use these P and S seismic waves to confirm that the outer core is liquid?
Using waves of frequency and pich
Explanation:
There's always been water around us
A car has a mass of 1200 kg and a velocity of 14 m/s. Calculate the
momentum of the car.
Answer:
p = 16,800
Explanation:
an object has a velocity of 0.12 rad/s. how many revolutions will the object make after traveling for 30 seconds?
Answer:
We can write S = v * t where S is the distance traveled in time t
S = .12 rad/sec * 30 sec = 3.6 rad distance traveled
Also 2 * pi * N = S since there are 2 * pi rad / revolution
So 2 * pi * N = 3.6
N = 3.6 / (2 * pi) = .573 revolutions
Will give brainliest!!
If 30 grams of potassium chloride dissolved in 100 g of water at 70 o C, would the solution be saturated, unsaturated or supersaturated.
explain why a diver at the bottom of the sea feels more pressure than one who is swimming on the surface of water
Answer:
the deeper into the ocean you go, the more pressure is exerted on you
Explanation:
1.00 x 10^8 kg of clear liquid (specific heat
capacity = 5.11 x 10^2 J/kg•°C) at a temperature
of 15.0°C gains 3.33 x 10^6 J of heat. What is the
final temperature of the liquid? (Assume the
melting point is less than 15.0°C and the boiling
point is greater than 62.0°C.)
Which two elements make up most of the Sun’s mass?
Question 4 options:
Hydrogen and oxygen
Carbon and nitrogen
Oxygen and carbon
Hydrogen and helium
Answer:
hydrogen and helium
Explanation:
i got it 100 percent. Hope this Helps!
A coaxial cable consists of an inner cylindrical conductor of radius 3 cm on the axis ofan outer hollow cylindrical conductor of inner radius 7 cm and outer radius of 10 cm.The inner conductor carries current 4.5 A in one direction, and the outer conductor carries current 8 A in the opposite direction. What is the value of the magnetic field atfollowing distances from the axis of the cable:
Answer:
Hello your question lacks some information and that is the distance
At r = 0.150 m (outside the cable) note : (μ 0 = 4π × 10-7 T · m/A)
answer: 4.7 * 10^-6 T
Explanation:
R1 = 0.03 m
R2 = 0.07 m
R3 = 0.1 m
Inner conductor carries current = 4.5A in one direction
outer conductor carries current = 8A in opposite direction
Determine the value of magnetic field at r = 0.150 m
net current = 8 - 4.5 = 3.5 A
∴ β ( value of magnetic field )
= ( 4π * 10^-7 * 3.5 ) / ( 2π * 0.150 )
= 4.4*10^-6 / 0.94
= 4.7 * 10^-6 T
Will give brainliest!!
How much KClO3 is needed to make a saturated solution in 100 mL of water at 70⁰ C?
Answer:
iam not sure but I think its NaNO3
Electromagnetic waves can carry more data at higher frequencies. Why would a scientist opt to transmit data at a lower frequency instead?
What are the limitations of sending information using electromagnetic waves?
What are the differences between analog and digital signals?
What are the advantages of using digital signals over analog signals?
Using reliable internet sources, identify three ways we use analog and digital signals in our everyday lives.
Describe how radio telescopes are used to explore space.
How are radio waves used on Earth?
Why do radio telescopes convert radio waves (analog signals) to electrical (digital) signals for analysis? (Hint: What did the article say about the advantages of digital signals?)
Very large forces are produced in joints when a person jumps from some height to the ground. (a) Calculate the magnitude of the force (in N) produced if a 62.0 kg person jumps from a 0.800 m-high ledge and lands stiffly, compressing joint material 1.50 cm as a result. (Be certain to include the weight of the person.) N (b) In practice the knees bend almost involuntarily to help extend the distance over which you stop. Calculate the magnitude of the force (in N) produced if the stopping distance is 0.300 m. N (c) Compare both forces with the weight of the person.
Answer:
a) F = 3.3 10⁴ N, b) F = 2.2 10³ N, c) force when rigid is 15 times greater than when bending the knees
Explanation:
For this exercise we can use the relationship between work and the variation of kinetic energy
K₀ = ½ m v²
the final kinetic energy is zero because the person is stationary
W = (∑ F) x
W = W x - F w
the weight is in the same direction of the displacement therefore the work is positive and the force applied, by the floor, is in the opposite direction to the displacement, consequently the work is negative
we substitute
( W- F ) x = 0-K₀
F = W + K₀ /x
F = mg + [tex]\frac{1}{2} \frac{mv^2 }{2x}[/tex]
F = m ( g+ [tex]\frac{v^2 }{2x }[/tex] )
Let's use kinematics to find the velocity of the person when reaching the floor
v² = v₀² - 2g (y + y₀)
the initial velocity is true and when reaching the ground y = 0
v² = -2 g (0-yo)
we calculate
v = [tex]\sqrt{2 ] 9.8 \ 0.800}[/tex]
v = - 3.96 m/s
the direction of this velocity is vertical down
let's calculate
a) x = 1.50 cm = 0.0150 m
F = 62.0 (3.96² / 2 0.0150 + 9.8)
F = 3.3 10⁴ N
b) x = 30 cm = 0.30 m
F = 62.0 (3.96² / 2 0.30 + 9.8)
F = 2.2 10³ N
c) to compare the force let's look for the relationship between the two
[tex]\frac{F_{rigid} }{ F_{flexible} }[/tex] = 3.3 10⁴ / 2.2 10³
\frac{F_{rigid} }{ F_{flexible} } = 15
therefore see that the force when rigid is 15 times greater than when bending the knees
