Answer:
the only correct answer is: Photons of lower-frequency light don't have enough energy to eject an electron
Explanation:
This question is in the model of the photoelectric effect, where some electrons are expelled from the metal by the action of a ray of light.
This effect was explained by Einstein supposes that the light rays are formed by photons and the energy of these photons is given by the Planco relation
K = h f - Ф
where K is the kinetic energy of the ejected electrons and Ф is the work function, it keeps the electrons inside the material.
When analyzing this expression there is a minimum frequency (threshold) for which K = 0
hf = Ф
Below this frequency the photons in the light beam do not have the energy to expel the electrons from the material.
Let's examine the answers
a) True. You agree with the above
b) False. The analysis is in terms of individual shock
c) False. The expulsion does not have to do with the number of photons but with the energy of each one
therefore the only correct answer is: Photons of lower-frequency light don't have enough energy to eject an electron
Proton traveling across a capacitor A proton enters with a velocity v between the plates of a capacitor as shown in the figure. What is the direction of the magnetic field needed so that the proton continues its trajectory, undeflected? Explain each step of your reasoning.
Answer:
Please see the direction of force in the attachment
Explanation:
As the particle enters the capacitor, it experiences electric. In order to move in the same direction as the electron was moving before entering the capacitor, the force due to the electric field of capacitor must be balanced by the magnetic field.
The direction of particle is shown in the attachment.
As we know,
Force = q (v *B)
You need to design a spring that will launch a 1060 kg satellite with a speed of 3.35 m/s relative to an orbiting space station. The maximum safe acceleration of the satellite is 5.00g, (g being the usual gravitational field constant on the surface of the Earth). The spring's mass, the recoil kinetic energy of the space station, and changes in gravitational potential energy will all be negligible.What must the force constant of the spring be
Answer:
226.8 kN/m
Explanation:
The work done by the spring, W equals the kinetic energy of the satellite, K
W = K
work done by the spring, W = 1/2kx² where k = force constant and x = extension of spring
kinetic energy of the satellite, K = 1/2mv² where m = mass of satellite = 1060 kg and v = speed of satellite = 3.35 m/s
1/2kx² = 1/2mv²
k = mv²/x²
Also, the spring force F = kx where k = force constant and x = extension of spring.
k = F/x
equation both expressions for k, we have
mv²/x² = F/x
x = mv²/F since F = ma where m = mass of satellite and a = maximum acceleration of satellite = 5.00g and g = 9.8 m/s²
x = mv²/ma = mv²/5.00mg = v²/5.00g
Substituting the values of the variables into the equation, we have
x = v²/5.00g
= (3.35 m/s)²/(5.00 × 9.8 m/s²)
= 11.2225 m²/s²/49 m/s²
=0.229 m
Now k = F/x = 5.00mg/x
Substituting the values of the variables into the equation, we have
k = 5.00mg/x
k = 5.00 × 1060 kg × 9.8 m/s²/0.229 m
k = 51940 kgm/s²/0.229 m
k = 51940 N/0.229 m
k = 226812.23 N/m
k = 226.81223 kN/m
k ≅ 226.8 kN/m
Approximate the human form as an unclothed vertical cylinder of 0.3 m diameter and 1.75 m length with a surface temperature of 30 oC.(a)Calculate the heat loss in a 10 m/s wind at 20 oC.(b)What is the heat loss if the skin is covered with a thin layer of water (i.e., sweat) at 30 oC and the relative humidity of the air is 60 %
Answer:
[tex]q=1118.865W[/tex]
Explanation:
From the question we are told that
Diameter of the cylinder [tex]D=0.3m[/tex]
Length of the cylinder [tex]L=1.75m[/tex]
Surface temperature of cylinder [tex]T_s=30 \textdegree C=303k[/tex]
Speed of air [tex]V=10m/s[/tex]
Temperature of air [tex]T=20 \textdegree C[/tex]
Generally the equation for Reynolds number is mathematically given by
[tex]Re_D=\frac{VD}{v}[/tex]
where
[tex]v=15.27*10^-^6[/tex]
[tex]Re_D=\frac{10*0.3}{15.27*10^-^6}[/tex]
[tex]Re_D=1.96*10^5[/tex]
Generally the equation for Nusselt number is mathematically given by
[tex]N_u=0.6(Re_D)^{0.6}(Pr)^{0.37}[/tex]
where
Prandtl number
[tex]Pr=0.71[/tex]
[tex]N_u=0.6(Re_D)^{0.6}(Pr)^{0.37}[/tex]
[tex]N_u=0.6(1.96*10^5)^{0.6}(0.71)^{0.37}[/tex]
[tex]N_u=791.53[/tex]
Generally the equation for convective heat transfer is mathematically given by
[tex]h=Nu \frac{k}{D}[/tex]
where
[tex]k=25.7*10^{-3}[/tex]
[tex]h=791.53*\frac{25.7*10^{-3}}{0.3}[/tex]
[tex]h=67.81W/m^2K[/tex]
Generally the equation for surface area of a cylinder is mathematically given by
[tex]A=\pi DL[/tex]
[tex]A=\pi *0.3*1.75[/tex]
[tex]A=1.65m^2[/tex]
Generally the equation for convective heat transfer is mathematically given by
[tex]q=h4(T_s-T_{inty)}[/tex]
[tex]q=(67.81)*1.65*(30-20)\\[/tex]
[tex]q=1118.865W[/tex]
HELP PLZZZZZ
Vitiligo is an example of a condition that comes from
A. your habits
B. your predisposed genetics
C. your social network
D. your physical environment
Answer:
the answer is b vitiligo is a genetic skin condition
How do pigs mate with eachother?
Answer:
Pigs enjoy touching each other and make nuzzling a part of their courtship. During courtship, the boar may nudge and nuzzle the sow's flank, head, genital area and shoulders, showering her with his attention. The sow and boar sing to each other as they nuzzle and chase each other.
Explanation:
wanna rp?
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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:
The electric field at the center of a ring of charge is zero. At very large distances from the center of the ring along the ring's axis the electric field goes to zero. Find the distance from the center of the ring along the axis (perpendicular to the plane containing the ring) at which the magnitude of the electric field is a maximum. The radius of the ring is 7.55 cm and the total charge on the ring is 7.06E-6 C.
Answer:b[tex]4.29\times 10^6\ N/C[/tex]
Explanation:
Given
The radius of the ring is [tex]a=7.55\ cm[/tex]
The charge on the ring is [tex]Q=7.06\times 10^{-6}\ C[/tex]
Electric field along the axis at a distance [tex]x[/tex] is given by
[tex]E=\dfrac{kxQ}{(x^2+a^2)^{\frac{3}{2}}}[/tex]
To get the maximum value, differentiate [tex]E[/tex] w.r.t [tex]x[/tex] we get
[tex]E_{max}=\dfrac{2kQ}{3\sqrt{3}a^2}\quad [\text{at}\ x=\dfrac{a}{\sqrt{2}}]\\\\E_{max}=\dfrac{2\times 9\times 10^9\times 7.06\times 10^{-6}}{3\sqrt{3}(7.55\times 10^{-2})^2}\\\\E_{max}=\dfrac{24.456\times 10^3}{57\times 10^{-4}}=4.29\times 10^6\ N/C[/tex]
PLEASE HELP ASAP
Jane told jill that the name sunflower comes from the fact that sunflowers follow the sun in the sky through out the day. jane said that sunflowers actually turn around on their stems to find the sun. to test this idea, jane and jill designed an experiment. they grew a pot of sunflowers outside in natural sunlight, one pot in the house near, but not directly in front of a window, and the final pot inside the house, away from all windows. the girls charted the direction of the sunflower heads throughout the day. all other growing conditions were the same: soil, water, pot size. the girls could not regulate the outdoor temperature, but since it was spring, the day and night temperatures were pretty close to the indoor temperature. which is an appropriate hypothesis for this experiment?
a) sunflowers will only grow in natural light.
b) sunflowers grown indoors will bend toward a source of natural light.
c) sunflower heads turn to follow the location of the sun, both indoors and out.
d) sunflowers grown away from natural light will not be as tall as sunflowers grown outdoors.
#1 - Saturn has a mass of 5.683 x 10^26 kg. One of its moons, Titan, has a
mass of 1.345x10^23 kg. The center of Saturn to the center of Titan is 1.222
x 10^6 m. What is the magnitude of the gravitational force that attracts
Saturn and Titan? Please show work and formula
Answer:
F = G M1 M2 / R^2 attractive force
F = 6.67 * 10E-11 * 5.683 * 10E26 * 1.345 * 10E23 / (1.222 * 106)^2 N
F = 6.67 * 5.683 * 1.345 / 1.493 * 10E26 N = 3.414 * 10E27 N
Chemotherapy is used to treat
cervical cancer.
endometriosis.
undescended testicles.
benign prostatic hypertrophy.
Answer:
cervical cancer
Explanation:
EDGE 2020
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
: A small block with mass 0.130 kg is attached to a string passing through a hole in a frictionless, horizontal surface. The block is originally revolving in a circle with a radius of 0.800 m about the hole with a tangential speed of 4.00 m/s. The string is then pulled slowly from below, shortening the radius of the circle in which the block revolves. The breaking strength of the string is 30.0 N. What is the radius of the circle when the string breaks
Answer:
r = 0.0173 m = 1.73 cm
Explanation:
Here, the centripetal force of the block will be providing the required breaking tension in the string:
[tex]Tension = Centripetal Force\\T = F_c\\\\T = \frac{mv^2}{r} \\\\r = \frac{mv^2}{T}\\[/tex]
where,
r = radius = ?
m = mass of block = 0.13 kg
v = tangential spee of block = 4 m/s
T = Breaking Strength = 30 N
Therefore,
[tex]r = \frac{(0.13\ kg)(4\ m/s)^2}{30\ N}[/tex]
r = 0.0173 m = 1.73 cm
When finding the radius of the string at the point it breaks, the tangential
velocity is assumed to be constant.
The radius when the string breaks is [tex]\underline{6.9 . \overline 3 \times 10^{-3}} \ m[/tex]Reasons:
The mass of the small block, m = 0.130 kg
Initial radius of the circle of rotation = 0.800 m
Tangential velocity, v = 4.00 m/s
The radius of the path of rotation is reduced as the string is pulled
Breaking strength of the string = 30.0 N
Required:
The radius of the circle when the string brakes
Solution:
[tex]Centripetal \ force = \dfrac{m \cdot v^2}{r}[/tex]
Where;
r = The radius of the circle of rotation
When the string brakes, w have;
Centripetal force = Breaking strength of the string = 30.0 N
Which gives;
[tex]\displaystyle r = \mathbf{\dfrac{m \cdot v^2}{Centrifugal \ force}} = \frac{0.130 \times 4^2}{30} =6.9\overline 3 \times 10^{-2}[/tex]
The radius of the circle when, the string breaks r = [tex]\underline{6.9\overline 3 \times 10^{-2}} \ m[/tex]
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What keeps the Earth's atmosphere from floating away? Earth's gravity keeps the air molecules of the atmosphere from escaping the area surround Earth The attraction between the different molecules of atmospheric gases The temperature of the gas is not high enough to allow it to spread out and escape the area surrounding Earth The differentiation between temperatures of the Earth and outer space traps the gases in the atmosphere
Answer: it is the earth gravity :’)
Explanation:
Earth's gravity keeps the air molecules of the atmosphere from escaping the area surround Earth
In which direction does the magnetic field in the center of the coil point?
A. Left
B. Down
C. Right
D. Up
The direction of the magnetic field in the center of the coil point towards the up. So, the correct option is D.
What is right-hand grip rule ?Right-hand grip rule states that, if you are holding a current carrying conductor with your right hand, such that the curled fingers point towards the direction of current flowing through the conductor, then the thumb will point towards the direction of the magnetic field.
Here,
From the current carrying conductor given,
The current is flowing through the conductor in a direction from left to right or it can be said as, the current is flowing in a clockwise direction.
So, we can apply the right-hand grip rule in this conductor.
According to the right-hand grip rule, stretch the thumb of the right hand and point it towards the direction of flow of current in the conductor. Then the remaining curled fingers will be pointed upwards in the conductor.
Hence,
The direction of the magnetic field in the center of the coil point towards the up.
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Which statements about magnetic fields are true? Choose more than one answer.
They attract certain metals
They require electric currents
They exert force
Electricity can create them
They grow stronger with distance from the magnet
They all have the same strength
Answer: THEY ATTRACT CERTIN METALS
THEY REQUIRE ELECTRIC CURRENTS
THEY EXERT FORCE
Explanation:
The true statements about magnetic fields are
They attract certain metals.They require electric currents.They exert force.What is magnetic fields?The magnetic field is the area around a magnet in which the effect of magnetism is felt. The magnetic field is used to describe how the magnetic force is distributed in the space around and within something magnetic in nature.
A moving charge in a magnetic field experiences a force perpendicular to its own velocity and to the magnetic field.
The properties of magnetic field are
The direction of the magnetic field lines is from the south pole to the north pole.Magnetic field lines never intersect with each other.Magnetic field lines form a closed-loop.Field lines have both direction and magnitude at any point on the field.To learn more about magnetic field here
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How are newtons third law and his law of universal gravitation are connected
Answer:
please give me brainlist and follow
Explanation:
Gravitational force keeps it attracted to the Earth, and centripetal force keeps it moving in a circle. ... Explain how Newton's third law and his law of universal gravitation are connected. His third law states that every force has an equal opposite force attracted to it, and that force is caused by gravity.
A block is pulled
7.00 meters along a
horizontal
surfacewith a
constant 30.0
newton force.
Calculate the
workdone on the
block.
The work done by the force for pulling a block till 7 meter along horizontal direction by using force of 30 N is, 210 joules.
What is work ?In physics, the work is defined as product of Force in the direction motion into distance travelled.
The work done on the block is given by the formula:
Work = Force x Distance x Cos(θ)
where Force is the force applied on the block, Distance is the distance the block is moved, and θ is the angle between the force and the direction of motion.
Given that,
F = 30 N
Distance = 7 m
W = ?
The force is constant and the surface is horizontal,
so the angle θ is equal to 0°, and cos(0°) is equal to 1.
Therefore, the work done on the block can be calculated as:
Work = Force x Distance x Cos(θ)
= 30.0 N x 7.00 m x 1
= 210 J
So, the work done on the block is 210 Joules.
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State Newton’s Universal Law of Gravitation.
Answer:
This law states that every particle attract every other particle in the universe with a force that is directly proportional to the product of their mass and inversely proportional to the square of the distance between the center
Does gravity increase or decrease with greater distance?
Which phrase best describes the structure of an atom?
A. A nucleus made up of protons, surrounded by an electron cloud
B. A nucleus made up of protons and neutrons, surrounded by
electrons in set orbits
C. A sphere made up of an equal number of protons, neutrons, and
electrons
D. A nucleus made up of protons and neutrons, surrounded by an
electron cloud
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.
A point source of light is located at the bottom of a steel tank, and an opaque circular card of radius is placed horizontally over it. A transparent fluid is gently added to the tank so that the card floats on the fluid surface with its center directly above the light source. No light is seen by an observer above the surface until the fluid is deep. What is the index of refraction of the fluid
PLEASE HELP
name 4 fundamentally different options for cooking a chicken
Answer:
roasting,
broiling,
pan-broiling,
pan-frying,
grilling.
Explanation:
good luck
Answer:
Explanation:
1. Stir frying
2. Pan frying
3. Grilling /BBQ
4. Baking/roasting
What is a positive effect of increased carbon dioxide within the carbon cycle?
Answer:
The positive impact in the cycle is that CO2 will make plants to use water more efficiently and also thereby make them to become drought resistant and thereby grow faster.
Explanation:
Carbon cycle is the process by which carbon dioxide travels from the atmosphere to the earth and returns back to the atmosphere.
The negative impact of carbon dioxide in the carbon cycle is that it will cause green house effect. However, when it comes to the positive impact in the cycle, CO2 will make plants to use water more efficiently and also thereby make them to become drought resistant and thereby grow faster.
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
1. An atom that loses electrons has a ________________________ charge and an atom that gains
electrons has a ___________________________ charge.
Charged atoms are called ___________________.
2. What is an insulator? Give 4 examples.
3. What is a conductor? Give an example.
4. How can we move electrons from one place to another? What actually causes the electrons to
move?
5. Static electricity is ______________________________________________________________________
_______________________________________________________________________________________
6. Explain the attraction and repulsion of charges.
7. Why does a balloon stick to the wall?
8. Why does your hair stand up when you take off your hat?
9. Why do you get a shock when you walk across a carpet?
10. When is static electricity most noticeable and why?
11. State the Principle of Conservation of Charge.
12. The invisible electric force field around charged objects depends on __________________________,
__________________________, and _____________________________.
13. What is the relationship between the charges and the field strength?
What is the relationship between the field strength and the distance between the charges?
1. What is DC?
What is AC?
2. Name 3 ways to get DC.
3. What is an electrical circuit?
4. What is voltage?
What is current?
What is resistance?
What causes heat and light in a wire?
COPY THE TABLE comparing water in a hose-DC-units
5. Which electricity do we use in our homes?
CLICK ON ALTERNATING CURRENT
1. Explain AC.
2. Who invented the light bulb?
3. Who really invented AC?
4. Who discovered the advantages of AC over DC?
5. How is AC made?
6. What is the main advantage of AC over DC?
The red shifting of the nebula that Slipher observed was also referred to as what?
Answer:
Slipher developed spectrographic methods that allowed researchers to see a Doppler effect in the distances of what were then called “spiral nebula,” what we today call galaxies. Simply put, by measuring the longer wavelength red shift (objects moving away) and shorter wavelength blue shift (objects moving closer), Slipher demonstrated that the universe was not static.
Explanation:
An explosive eruption by a single volcano can affect
OA. only the lifeforms living on the volcano.
OB. only the lifeforms living on the same continetu
OC. lifeforms throughout the world.
OD. Earth's climate but not its lifeforms.
Why does an energy transfer not always result in phase change?
Answer:
Explanation:
The energy transfer are not changing in kinetic energy. They are changes in bonding energy between the molecules.
Kieran is graduating from high school. He wants to be a urologist. What career path would be best for Kieran to follow?
four-year degree Right arrow. graduate school Right arrow. residency
four-year degree Right arrow. graduate school Right arrow. license from the NCLEX
two-year degree Right arrow. license from the NCLEX Right arrow. certification in a specialty
two-year degree Right arrow. vocational school Right arrow. further certification
Answer:
four-year degree Right arrow. graduate school Right arrow. residency
Explanation:
edge
Four-year degree Right arrow. graduate school Right arrow. residency. This career path would be best for Kieran to follow.
What is career ?According to the Oxford English Dictionary, a person's "career" is their "course or progress through life." According to this definition, a person's "career" includes a variety of facets of their life, education, and employment. The term "career" is also widely used to refer to the professional parts of a person's life, as in "career woman," for instance. A profession or occupation that often requires specific training or formal education is referred to as a person's lifework in the third manner that the word "career" is employed.When used in this context, "a career" refers to a set of linked occupations that are often followed within a single industry or sector. For instance, one may speak of "a career in education," "a career in criminal justice," or "a career in the building trade."
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