The work function of the cathode is found to be 0.10 eV, calculated by using the relationship between the maximum kinetic energy of photoelectrons, the photon energy, and the work function within the context of the photoelectric effect.
The question involves finding the work function of a cathode in a photoelectric effect scenario. We know that the maximum kinetic energy (KE) of photoelectrons is related to the photon energy (hf) and the work function (
W) as KE = hf - W. We were given that the kinetic energy decreased to 1.50 eV when the wavelength increased by 50%, which implies the initial wavelength corresponds to a photon energy that gives photoelectrons a kinetic energy of 3.10 eV. Let's express these energies in the equation form:
KE1 = hf1 - W, where KE1 = 3.10 eV
KE2 = hf2 - W, where KE2 = 1.50 eV and hf2 = hf1/1.5 (since the wavelength increased by 50%, energy decreases by the same factor)
By subtracting the second equation from the first, we eliminate W and can solve for hf1. Once we have hf1, we can solve for the work function using either of the equations:
3.10 eV - 1.50 eV = hf1 - hf1/1.5
1.60 eV = 0.5 * hf1
hf1 = 3.20 eV
Work function W = hf1 - KE1 = 3.20 eV - 3.10 eV = 0.10 eV
The work function of the cathode is therefore 0.10 eV.
A mass of 15 kg of air in a piston-cylinder device is heated from 25 to 77°c by passing current through a resis tance heater inside the cylinder. the pressure inside the cylin der is held constant at 300 kpa during the process, and a heat loss of 60 kj occurs. determine the electric energy supplied, in kwh
A ray of light is traveling in a glass cube that is totally immersed in water. you find that if the ray is incident on the glass-water interface at an angle to the normal greater than 52.5 ∘, no light is refracted into the water. part a what is the refractive index of the glass?
f the ray is incident on the glass-water interface at an angle to the normal greater than 52.5 ∘ then Refractive index of the glass will be 1.26 by critical angle.
What is Refractive index?The optical medium's refractive index would be a dimensionless number that indicates how well the medium bends light. The refractive index controls however much light would be refracted or twisted when it enters a substance.
What is critical angle ?
Critical angle, in optics, the greatest angle at which a ray of light, travelling in one transparent medium, can strike the boundary between that medium and a second of lower refractive index without being totally reflected within the first medium.
critical angle = [tex]sin^{-1} (1/n)[/tex]
Put the value of critical angle in above equation.
52.5° = [tex]sin^{-1}(1/n)[/tex] = 1.26
Refractive index of the glass will be 1.26
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Using a crowbar, a person can remove a nail by exerting little force, whereas pulling directly on the nail requires a large force to remove it (you probably can't). why?
Final answer:
Using a crowbar to remove a nail requires less force because it uses leverage to amplify the input force and increase the mechanical advantage.
Explanation:
When using a crowbar to remove a nail, you are using a lever with a large mechanical advantage. The input force you apply to the crowbar is much smaller than the force exerted by the crowbar on the nail. This is because the length of the crowbar provides a greater lever arm, which increases the mechanical advantage.
On the other hand, when you try to pull directly on the nail, you don't have the same leverage as the crowbar, so you need to exert a larger force to overcome the resistance of the nail.
In summary, the crowbar allows you to remove a nail with less force because it uses leverage to amplify the input force and increase the mechanical advantage.
A stone is thrown outward from the top of a 59.4-m high cliff with an upward velocity component of 19.5 m/s. how long is stone in the air?
The stone is in the air for 6 seconds.
[tex]\texttt{ }[/tex]
Further explanationAcceleration is rate of change of velocity.
[tex]\large {\boxed {a = \frac{v - u}{t} } }[/tex]
[tex]\large {\boxed {d = \frac{v + u}{2}~t } }[/tex]
a = acceleration ( m/s² )
v = final velocity ( m/s )
u = initial velocity ( m/s )
t = time taken ( s )
d = distance ( m )
Let us now tackle the problem!
[tex]\texttt{ }[/tex]
Given:
height of the cliff = h = 59.4 m
speed of the stone = u = 19.5 m/s
Asked:
total time taken = t = ?
Solution:
[tex]h = ut + \frac{1}{2}at^2[/tex]
[tex]-59.4 = 19.5t - \frac{1}{2}(9.8)t^2[/tex]
[tex]-59.4 = 19.5t - 4.9t^2[/tex]
[tex]49t^2 -195t - 594 = 0[/tex]
[tex]( t - 6 ) ( 49t + 99 ) = 0[/tex]
[tex]t - 6 = 0[/tex]
[tex]t = 6 \texttt{ s}[/tex]
[tex]\texttt{ }[/tex]
Learn moreVelocity of Runner : https://brainly.com/question/3813437Kinetic Energy : https://brainly.com/question/692781Acceleration : https://brainly.com/question/2283922The Speed of Car : https://brainly.com/question/568302[tex]\texttt{ }[/tex]
Answer detailsGrade: High School
Subject: Physics
Chapter: Kinematics
[tex]\texttt{ }[/tex]
Keywords: Velocity , Driver , Car , Deceleration , Acceleration , Obstacle , Projectile , Motion , Horizontal , Vertical , Release , Point , Ball , Wall
A stone is thrown outward from the top of a 59.4-m high cliff with an upward velocity component of 19.5 m/s. The stone is in the air for 6 seconds.
What is acceleration?The rate at which an item changes its velocity is known as acceleration, a vector quantity. If an object's velocity is changing, it is acceleration.
Given in the question a stone is thrown outward from the top of a 59.4-m high cliff with an upward velocity component of 19.5 m/s.
Acceleration is rate of change of velocity.
a = acceleration ( m/s² )
v = final velocity ( m/s )
u = initial velocity ( m/s )
t = time taken ( s )
d = distance ( m )
height of the cliff = h = 59.4 m
speed of the stone = u = 19.5 m/s
to find total time taken = t = ?
s = ut + 1/2 at² putting the value we get,
t = 6 sec
The stone is in the air for 6 seconds.
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how high was a brick dropped from if if falls in 2.5 seconds?
When a guitar string plays the note "a," the string vibrates at 440 hz ?
Answer:
440hz
Explanation: Guitars do in fact play at 440 herts for the note a
What element below makes up 71% of the earth's crust?
A wave is a disturbance that carries from one place to another through matter and space.
Answer:
Energy
Explanation:
Eng 2021
If it takes 6.02 kj of heat energy to melt a mole of ice, how much heat is absorbed when 6.30 g of water melts? 21.0 j 2.10 kj 21 kj 0.210 kj
Why are objects that fall near Earth’s surface rarely in free fall?
Gravity does not act on objects near Earth’s surface.
Air exerts forces on falling objects near Earth’s surface.
The objects do not reach terminal velocity.
The objects can be pushed upward by gravity.
In terms of the torque needed to rotate your leg as you run, would it be better to have a long calf and short thigh or vice versa? a) Long calf, short thigh b) Short calf, long thigh c) Does not matter
Having a short calf and long thigh would result in better torque for leg rotation during running, as a longer lever arm (thigh) from the pivot point (knee) allows for greater torque. However, proportions should be balanced for optimal running biomechanics.
Explanation:In terms of the torque needed to rotate your leg as you run, it would be better to have a short calf and long thigh. This is because torque is the rotational equivalent of force and is calculated by multiplying the force by the distance from the pivot point. In this case, the pivot point is the knee.
Therefore, a longer thigh would result in a greater torque because the force (muscle contraction) is applied further from the pivot point (knee). Conversely, a short calf means less mass is being rotated around the pivot point, reducing the torque needed for movement.
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In terms of the torque needed to rotate your leg as you run, it be better to have b) Short calf, long thigh
In terms of the torque needed to rotate your leg as you run, it would be better to have a short calf and long thigh.
This is because torque is the rotational equivalent of force, and it depends on both the magnitude of the force and the distance from the pivot point where the force is applied. In running, the longer the distance from the pivot point (knee), the more torque is generated by the same muscle force. A long thigh and short calf combination helps in maximizing this distance, thereby reducing the effort required to achieve the same angular acceleration of the leg.
Let's break this down step-by-step:
Torque (τ) is defined as τ = r × F, where r is the distance from the pivot point (in this case, the knee) and F is the force applied by the muscles.For a given force, increasing the distance r will increase the torque, making it easier to rotate the leg.A long thigh means a greater r from the hip pivot point, increasing the torque generated for the same muscle effort.A short calf means less weight and less moment of inertia that needs to be rotated, making the rotation more efficient.What was the speed of the cannon ball if the spring compressed 58 cm when the cannon was fired?
To calculate the speed of a cannon ball using the distance the spring compressed, the spring constant is required to use energy conservation principles. Without this value, it is not possible to provide an exact answer.
To determine the speed of the cannon ball given that the spring compressed 58 cm when it was fired, we would use the conservation of energy principle where the potential energy stored in the spring is converted into the kinetic energy of the cannon ball. If we had the spring constant (k), we could use the formula for the potential energy stored in a spring, which is PE_spring = (1/2)kx² where x is the compression distance, and equate this to the kinetic energy formula KE = (1/2)mv², where m is the mass of the cannon ball, and v is the velocity we want to find. Without the specific spring constant, it is not possible to calculate the exact speed of the cannon ball.
How much work does an elevator motor do to lift a 1200-kg elevator car a height of 80 m at constant speed?
Answer:
Work = 940800 J
Explanation:
As we know that work done is defined as
Work = (Force)(displacement in the direction of force)
here elevator motor lift a mass of 1200 kg
so in order to lift it up motor must have to apply the force same as the weight so that it will move up with constant speed.
so here we have
[tex]F = mg[/tex]
[tex]F = (1200 kg)(9.8 m/s^2)[/tex]
[tex]F = 11760 N[/tex]
now it is displaced upwards by distance d = 80 m
so here we have
[tex]W = (11760)\times (80)[/tex]
[tex]W = 940800 J[/tex]
so above is the work done by the elevator to lift it upwards
"why might a good electrical conductor also be a good thermal conductor"
If r1 < r2 < r3, and if these resistors are connected in series in a circuit, which one dissipates the most power
A charge of 7.2 × 10-5 C is placed in an electric field with a strength of 4.8 × 105. If the electric potential energy of the charge is 75 J, what is the distance between the charge and the source of the electric field? Round your answer to the nearest tenth.
The distance between the charge and the source of the electric field is 2.2 m.
The potential energy U of a charge q placed in an electric field created by a source charge Q, at a distance r from the source charge is given by,
[tex] U=\frac{kQq}{r} [/tex] ...... (1)
Here, k is the Coulomb constant.
The electric field E at a distance r from the source charge is given by,
[tex] E =\frac{kQ}{r^2} [/tex] ......(2)
From equations (1) and (2)
[tex] U=E*q*r [/tex]
Rewrite the expression for ri.
[tex] r=\frac{U}{Eq} [/tex]
Substitute 75 J for U, [tex] 4.5*10^5 V/m [/tex] for E and [tex] 7.5*10^{-5} C [/tex] for q.
[tex] r=\frac{U}{Eq} \\ =\frac{75 J}{(4.8*10^{5} V/m)(7.2*10^{-5}C)} \\ =2.17 m [/tex]
Rounding off to the nearest tenth, the the distance between the charge and the source charge is 2.2 m
Two appliances are connected in parallel to a 120-v battery and draw currents i1 = 3.0 a and i2 = 3.1
a. if these appliances are instead connected in series to the same battery, what is the total current in the circuit?
A piano tuner stretches a steel piano wire with a tension of 765 n. the steel wire has a length of 0.700 m and a mass of 5.25 g . part a what is the frequency f1 of the string's fundamental mode of vibration?
The fundamental frequency of the steel piano wire, subjected to a tension of 765 N, with a length of 0.700 m, and a mass of 5.25 g, is approximately 424.6 Hz.
Explanation:The frequency f1 of the string's fundamental mode of vibration can be calculated using the formula f = sqrt(T / μ) / 2L. Here:
T is the tension in the string, which is 765 Nμ is the linear density of the string, which is the mass of the string divided by its length. Therefore, μ = (5.25 g) / (0.700 m) = 0.0075 kg/mL is the length of the string, which is 0.700 mPlugging these values into the formula, we get:
f1 = sqrt((765 N) / (0.0075 kg/m)) / (2 * 0.700 m) = 424.6 Hz
This means that the fundamental frequency of the string is roughly 424.6 Hz.
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A cylinder with a moveable piston contains 219 ml of nitrogen gas at a pressure of 1.23 atm and a temperature of 295 k . part a what must the final volume be for the pressure of the gas to be 1.53 atm atm at a temperature of 337 k ?
The final volume needed for the pressure of the nitrogen gas to be 1.53 atm at a temperature of 337 K is approximately 190.8 ml. This is calculated using the combined gas law.
Explanation:To find out what the final volume of nitrogen gas in the cylinder would be when the pressure is 1.53 atm and the temperature is 337 K, we can use the combined gas law, which is derived from the ideal gas law. The combined gas law states that the ratio of the product of pressure and volume to temperature remains constant for a fixed amount of gas when the temperature is measured in Kelvin. The formula for the combined gas law is (P1 * V1) / T1 = (P2 * V2) / T2, where P is pressure, V is volume, and T is temperature.
Given that:
Initial pressure (P1) = 1.23 atmInitial volume (V1) = 219 mlInitial temperature (T1) = 295 KFinal pressure (P2) = 1.53 atmFinal temperature (T2) = 337 KWe want to find the final volume (V2), so rearranging the equation to solve for V2 gives us:
V2 = (P1 * V1 * T2) / (P2 * T1)
Substituting the known values:
V2 = (1.23 atm * 219 ml * 337 K) / (1.53 atm * 295 K)
By performing the calculations:
V2 ≈ 190.8 ml
Therefore, the final volume needed for the pressure of the nitrogen gas to be 1.53 atm at 337 K is approximately 190.8 ml.
Dr. Lao has discovered a substance that emits energy in the form of waves. If Dr. Lao observes that these waves can travel through a perfect vacuum, then
Answer: The waves that travel through vacuum is electromagnetic waves.
Explanation:
There are two types of waves:
Mechanical waves: These are the waves that need a medium to travel so that they can transport their energy from one location to another. For Example: Sound waves
Electromagnetic waves: These are waves which can travel through vacuum. These have electrical and magnetic component associated with them. They travel with the speed of light. They does not require a medium to travel. For Example: Infrared waves, Microwaves
Hence, the waves that travel through vacuum is electromagnetic waves.
A cyclist is riding his bike up a mountain trail. When he starts up the trail, he is going 8 m/s. As the trail gets steeper,he slows to 3 m/s in 1 minuet. What is the cyclist acceleration
Which of the following occurs over a resistor in a circuit? Current is dissipated. Voltage is dropped. Charge is stored. Electrical energy is stored.
In a circuit, a voltage drop occurs over a resistor as the electric current flows through it, transforming electrical energy into heat due to resistance, not storing charge or electrical energy. the correct answer is voltage is dropped.
Among the choices provided for what occurs over a resistor in a circuit, the correct answer is voltage is dropped. When electric current flows through a resistor, it encounters resistance which impedes the flow of charge. This results in a voltage drop across the resistor. The energy that the charges lose as they pass through the resistor is dissipated mainly in the form of heat. This concept is reflected in the equation for electric power dissipation, P = IV, where P represents power, I is current, and V is voltage. This can also be expressed as P = I²R or P = V²/R using Ohm's law, where R is the resistance. Contrary to some of the other choices, resistors do not store charge or electrical energy; that function is typically carried out by capacitors in a circuit.
When you push a 1.87-kg book resting on a tabletop, it takes 2.02 n to start the book sliding. once it is sliding, however, it takes only 1.47 n to keep the book moving with constant speed. what is the coefficient of static friction between the book and the tabletop?
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Which accurately compares concave and convex lenses?
A. With both concave and convex lenses, the characteristics of the image do not depend on the placement of the object.
B. With both concave and convex lenses, the characteristics of the image depend on the placement of the object.
C. With concave lenses, the characteristics of the image do not depend on the placement of the object, but with convex lenses, they do.
D. With convex lenses, the characteristics of the image do not depend on the placement of the object, but with concave lenses, they do.
With concave lenses, the characteristics of the image do not depend on the placement of the object, but with convex lenses, they do.
A rocket in orbit just above the atmosphere is moving in uniform circular motion. The radius of the circle in which it moves is 6.381 × 106 m, and its centripetal acceleration is 9.8 m/s2 . What is the speed of the rocket?
Chanel has some cotton candy that came in a cloudy shape. She wants to make it more dense. Which describes the candy before and after Chanel manipulated it?
1)The candy before was a cube, and the candy after was a ball.
2)The candy before was compacted, and the candy after was fluffy.
3)The candy before was fluffy, and the candy after was compacted.
4)The candy before was a ball, and the candy after was a cube.
Answer: Option (C) is the correct answer.
Explanation:
As we known that density is the amount of mass divided by volume of the substance.
Mathematically, Density = [tex]\frac{mass}{volume}[/tex]
So, when candy was present in the shape of a cloud then it means that it was fluffy as it has more volume.
Since, density is inversely proportional to volume therefore, with increase in volume there will occur a decrease in density.
But when the candy will become compact then there will occur a decrease in its volume. Hence, then there will occur an increase in the density of the candy.
Thus, we can conclude that the statement candy before was fluffy, and the candy after was compacted best describes the candy before and after Chanel manipulated it.
A proton beam in an accelerator carries a current of 106 μa. if the beam is incident on a target, how many protons strike the target in a period of 17.0 s?
What is the maximum velocity for the pacific plate?
why were you able to see the effects of the magnetic fields using iron filings
An unmanned spacecraft leaves for Venus. Which statements about the spacecrafts journey are true?
A)The weight of the spacecraft keeps changing.
B)The mass of the spacecraft keeps changing
C)The weight of the spacecraft remains the same
D) The mass of the spacecraft remains the same
E)The gravotational pull on the spacecraft remains the same
Hint: There is more than one answer
Answer:
A)The weight of the spacecraft keeps changing.
D) The mass of the spacecraft remains the same
Explanation:
As we know that the acceleration due to gravity depends on the height from the surface
As we know that the force due to gravity on objects near the surface is given as
[tex]F = \frac{Gm_1m_2}{(R+h)^2}[/tex]
here we know that
R = radius of planet
h = height from the surface of planet
So as we move away at more height the gravitational attraction force will keep on decreasing.
This gravitational attraction force of planet is also known as weight so we can say that the weight of the object will keep on changing while object move away.
Also we know that mass of object is quantity of the matter which always remains constant.