In SEC, in what volume would you expect molecules that are much smaller than the fractionation range of the Sephadex SP to elute? A. Vi B. Vm C. Vav D. Vr E. Vo

Answer:

8.04 seconds

Explanation:

Assuming that the child starts from rest at the bottom of the hill and travels until she comes to a stop, we can use the following kinematic equation:

v_f^2 = v_i^2 + 2ad

where v_f is the final velocity (which is zero since the child comes to a stop), v_i is the initial velocity (which is the velocity at the bottom of the hill), a is the acceleration (-0.392 m/s²), and d is the distance traveled.

We can solve for d:

d = (v_f^2 - v_i^2) / (2a)

= (0 - v_i^2) / (2-0.392)

= v_i^2 / 0.784

Since the child is sliding along flat snow-covered ground, there is no change in elevation, so we can use the distance traveled from the bottom of the hill to the stopping point as the distance d.

To find the time it takes for the child to travel this distance, we can use the following kinematic equation:

d = v_it + 0.5a*t^2

where t is the time and all other variables are as previously defined.

Substituting the expression for d obtained above, we get:

v_i^2 / 0.784 = v_it + 0.5(-0.392)*t^2

Solving for t, we get:

t = (2 * v_i) / 0.392

We still need to find the value of v_i, the initial velocity of the child at the bottom of the hill. To do so, we can use conservation of energy. The child starts at rest at the top of the hill, so all the initial energy is potential energy. At the bottom of the hill, all the potential energy has been converted to kinetic energy. Assuming no energy is lost to friction, we can equate these two energies:

mgh = 0.5mv_i^2

where m is the mass of the child, g is the acceleration due to gravity (9.8 m/s²), and h is the height of the hill.

Solving for v_i, we get:

v_i = √(2gh)

Substituting this expression for v_i into the expression for t obtained earlier, we get:

t = (2 * √(2gh)) / 0.392

Plugging in the values of g, h, and a, we get:

t = (2 * √(29.820)) / 0.392 = 8.04 seconds

The angle of repose or the angle of friction is the angle at which the block starts to slide down the inclined plane. By balancing the forces operating on the block along the inclination, it may be calculated.

The gravitational force (mg) acting downhill and the normal force (N) acting perpendicular to the inclination are the forces acting on the block. The gravitational force component perpendicular to the inclination, which is calculated as mg cos, where is the angle of the incline, and the normal force are identical in magnitude.

The block can have a maximum static friction force (Ff) applied to it without it sliding down the incline if:

Ff = μs N

where s is the static friction coefficient.

The amount of the frictional force is equal to the component of the gravitational force parallel to the inclination, which is mg sin, at the instant the block just starts to slide.

learn more about angle here:

https://brainly.com/question/28451077

#SPJ4

Part A: Thrust acts on the right in the direction of motion. Gravity acts downward.

Part B:  The direction of air resistance is opposite to the direction of motion, which is shown towards the left. Gravity acts downwards.

Part A:

A free-body diagram for a car is as follows:

The direction of friction is opposite to the direction of motion, which is shown towards the left.
The diagram shows three forces acting on the toy car that is battery-powered, which is as follows:
The force due to friction is labeled as [tex]f_K[/tex].

The force of thrust is labeled as [tex]f_T[/tex]. The force of gravity is labeled as [tex]f_g[/tex].
Part B:

A free-body diagram for a rabbit is as follows:
The diagram shows three forces acting on the stuffed rabbit that is being pushed by a toy car that is battery-powered, which is as follows:

The direction of friction is opposite to the direction of motion, which is shown towards the right.
The force due to friction is labeled as [tex]f_K[/tex]. The force due to air resistance is labeled as fair. The force of gravity is labeled as [tex]f_g[/tex].
For similar question on Gravity

https://brainly.com/question/557206

#SPJ11

To find Young's modulus Y, use [tex]Y = mg( l1 - l0 ) / ( πr^2l0 )[/tex] with given values. For the spring constant k, use [tex]k = Yπr^2 / l0, with Y, r,[/tex] and l0 given. (a) Young's modulus Y is a measure .

the stiffness of a material and is calculated using the formula Y = (mg( l1 - l0 )) / ( πr^2l0 ), where g is the acceleration due to gravity. Substituting the given values,[tex]Y = 2.08 × 10^11 N/m^2.[/tex] This means that the steel cable is relatively stiff and can resist deformation under stress. n(b) The spring constant k of the steel cable indicates its stiffness as a spring, with a higher value indicating a stiffer material that will resist deformation more strongly. In this case, the steel cable has a relatively high spring constant of 9.16 × 10^4 N/m, meaning that it will not stretch much when a force is applied.

learn more about Young's modulus here:

https://brainly.com/question/30756002

#SPJ4

The correct comparison of the energy generation processes is "The Sun generates energy by fusing small nuclei into larger ones, while our power plants generate energy by the fission (splitting) of large nuclei". Thus, the correct options are A and B.

Nuclear reactions involve the alteration of an atom's nucleus in both cases. Nuclear power plants and the sun both use energy generated by these nuclear reactions to produce electricity. The difference is in the type of nuclear reaction that takes place.

In the Sun, nuclear fusion is the process by which atomic nuclei of low atomic number fuse to form a heavier nucleus with the release of energy. The energy produced in this way is what makes the Sun so hot and bright. In a nuclear power plant, nuclear fission is the process by which the nucleus of an atom is split into two smaller nuclei.

The energy that is released in the process is used to heat water, creating steam that drives a turbine, which in turn drives a generator to produce electricity.

Therefore, the correct options are A and B.

Learn more about Nuclear power here:

https://brainly.com/question/18769119

#SPJ11

Hydroelectric energy is generated by capturing the energy of flowing water. As water flows through a turbine, the blades of the turbine spin and generate electricity.

Wind energy is generated by capturing the kinetic energy of the wind. As wind passes through the turbine, the blades spin and generate electricity.

Geothermal energy is generated by harnessing the natural heat of the Earth’s core. Heat from the Earth’s core is used to generate steam, which is then used to spin a turbine and generate electricity.

Parabolic solar collection is a method of collecting the sun’s energy using large reflective mirrors. The mirrors focus the sunlight onto a central point, which is then used to spin a turbine and generate electricity.

Thus, all of these power sources rely on spinning turbines connected to a generator to produce electricity.

Read more about Electricity here:

https://brainly.com/question/158098

#SPJ11

When using compass orientation, migrating animals make use of the sun, stars, and Earth's magnetic field to navigate. So, option d is correct option.

Compass orientation in migrating animals is the process of using the sun, stars, and Earth's magnetic field to navigate. Migrating animals use a variety of techniques to navigate, depending on their species and environment.

Some animals use the position of the sun, stars, and Earth's magnetic field as their primary means of orientation when migrating. This is known as compass orientation.

Compass orientation is a technique that relies on environmental cues, such as the position of the sun and stars, to determine direction. Some animals can use the Earth's magnetic field to navigate as well. This is known as magnetic orientation.

Magnetic orientation is used by some species of birds and fish, as well as certain insects and reptiles. Other animals use landmarks and olfactory cues to navigate.

These animals rely on visual or chemical markers in the environment to orient themselves. This technique is known as piloting. Piloting is used by animals such as rodents, bats, and some species of birds. Animals that use piloting must be able to remember and recognize the landmarks they use as cues to navigate.

Finally, some animals use memories from previous trips with parents to navigate. This technique is known as true navigation. True navigation requires animals to have a highly developed sense of spatial awareness and memory. True navigation is used by animals such as sea turtles and some species of birds.

All of these techniques require different cognitive abilities and sensory mechanisms, but they allow animals to navigate over long distances to reach their desired destinations.

for similar question on magnetic field to navigate.

https://brainly.com/question/22986969

#SPJ11

Rutherfordium is a synthetic element with the atomic number 104 and symbol Rf. As a synthetic element, it is not found naturally on Earth and is produced through nuclear reactions in laboratories.

Rutherfordium is a member of the transition metals group and is expected to have similar physical and chemical properties to its neighboring elements in the periodic table. However, due to its radioactive nature and short half-life, its physical properties are difficult to determine.

While there is no experimental data available on the state of matter of rutherfordium at room temperature, it is expected to be a solid metal, similar to other transition metals, such as copper or nickel.

To learn more about matter refer to:

brainly.com/question/28591826

#SPJ4

The ratio of the low temperature to high temperature of the Carnot engine is 2.38.

The efficiency of the Carnot engine can be defined as the ratio of network done per cycle by the engine to the heat energy absorbed by the engine per cycle by the working substance from the source.

Efficiency = 1 - (Tlow/Thigh)


Heat absorbed by engine = 480J

Heat expelled by engine = 320J

Efficiency of the engine = 56% of efficiency of Carnot engine

The ratio of low temperature to high temperature in the Carnot engine.

Let's assume the efficiency of the Carnot engine is 'ηc' = 1 - T₂/T₁

Where, T₂ = Low temperature and T₁ = High temperature

To calculate the efficiency of the engine given, η = (Q1 - Q2)/Q1

η = (480 - 320)/480

η = 160/480

η = 1/3

η = 33.33%

Now, η = 56% × ηc

0.56ηc = 1/3ηc = (1/3)/0.56 = 0.58

As we already know, ηc = 1 - T₂/T₁

T₂/T₁ = 1 - ηc

T₂/T₁ = 1 - 0.58

T₂/T₁ = 0.42

T₁/T₂ = 1/0.42

T₁/T₂ = 2.38

Therefore, the ratio of low temperature to high temperature in the given Carnot engine with an efficiency of 56% will be about 2.38.

Learn more about Carnot engine here:

https://brainly.com/question/14680478

#SPJ11

Answer:

The original mass of the substance was 10g.

Explanation:

The half-life of a radioactive substance is the amount of time it takes for half of the substance to decay. In this case, the half-life is 5 hours.

We can use the half-life formula to find the original mass of the substance:

N = N0 * (1/2)^(t/T)

where:

---N0 is the initial mass of the substance

---N is the remaining mass of the substance after time t

---T is the half-life of the substance

We know that after 20 hours, only half of the substance remains:

N = N0 * (1/2)^(20/5) = 0.5 * N0

If we solve for N0, we get:

N0 = N / 0.5 = 5g / 0.5 = 10g

Therefore, the original mass of the substance was 10g.

The expression for the magnitude of the force exerted on the firefighter by the pole can be expressed as  F = mg + ma.  

Where m is the mass of the firefighter,

g is the acceleration due to gravity, and

a is the acceleration of the pole

In order to find an expression for the magnitude of the force, F, exerted on the firefighter by the pole, we need to consider the forces acting on the firefighter.

According to Newton's second law of motion, the force acting on an object is equal to its mass multiplied by its acceleration. In this case, the forces acting on the firefighter are the gravitational force, which is pulling the firefighter downwards with a force of mg, and the force exerted on the firefighter by the pole, which is pushing the firefighter upwards with a force of ma. Therefore, the total force acting on the firefighter is given by the sum of these two forces, which is: F = mg + ma

Thus, this expression gives us the magnitude of the force exerted on the firefighter by the pole. Here, m is the mass of the firefighter, g is the acceleration due to gravity, and a is the acceleration of the pole. if the pole is not accelerating (i.e., if a = 0), then the expression reduces to F = mg, which is the gravitational force acting on the firefighter.

To know more about Magnitude please visit :

https://brainly.com/question/30337362

#SPJ11

Answer:

b

Explanation: friction is like a force to something to react

At a given pressure, a substance in the saturated vapor phase will be at a lower temperature than a superheated vapor.

Saturated vapor refers to the state of a material in which it contains a maximum quantity of vapor that is uniformly blended with the liquid or solid state of the same chemical composition at a specified temperature and pressure.

A superheated vapor is a vapor that is heated beyond its boiling point or saturation temperature for its pressure. As a result, it will not condense back into a liquid phase until it has cooled sufficiently. As a result, it's simply vapor, with no liquid portion to it.

According to Charles's law, if the pressure of a gas is kept constant, the volume of the gas varies directly with the temperature. If pressure remains constant and temperature increases, the volume of a substance expands, indicating that molecules are gaining energy and colliding with one another more frequently. As a result, the kinetic energy of the system increases. When a substance is in a superheated vapor state, it is at a higher temperature than when it is in a saturated vapor state at the same pressure.

Learn more about saturated vapor phase here: https://brainly.com/question/13407628

#SPJ11

Answer:

The Moon has no atmosphere so there is no drag on the capsule to slow its descent; parachutes will not work. Lunar landing vehicles were equipped with rocket engines that were fired by the pilot to provide lift — thrust in the opposite direction of descent — during the rapid descent to the Moon's surface.

The moon does not harbor any appreciable atmosphere. Therefore no parachute, no matter how large, will operate properly on the moon. Air is required in order to inflate the parachute and slow down the descending object. Remember geologist Harrison Schmidt, the ONLY scientist to visit the moon? He was one of the last two people to ever touch the lunar surface. (Apollo 17). He demonstrated what would happen when two objects of different masses were dropped simultaneously from about five feet above the moon’s surface. He dropped a hammer and a feather. They fell at the same rate and hit the surface at exactly the same instant! There was no atmosphere to cause the feather to flutter. Note: Careful observers may notice that in videos of the the descending Apollo Lunar Lander (“The Eagle has landed”) lunar dust is kicked up by the craft’s engines. The dust moves out in straight lines, not in billowing clouds! PROOF that the film was made in the airless void of the moon and NOT in some clandestine film studio on Earth. No moon landing hoax!

"The surface of the sun appears sharp in visible light because the photosphere is thin compared to the other layers in the sun."

Most of the electromagnetic energy that reaches the earth begins in the photosphere, the area of the sun that is visible to us. The photosphere is referred to as the sun's surface, despite the fact that it is a gaseous entity.

The gas in the photosphere appears to have a sharp surface, but in reality, it is heavier lower in the Sun and less dense higher up. It is more transparent the less thick it is. The area of the gas that is visible to us is where it has largely become translucent. About 300 km of this layer are deep.

The photosphere is the line separating the core of the Sun from its atmosphere. It is the part of the Sun's surface that is visible to us. The photosphere is not like a planet's surface; even if you could stand in the sun, you couldn't do so on the photosphere.

To know more about Sun:

https://brainly.com/question/12498469

#SPJ4

In the heliocentric model of the solar system, one planet passing another in its orbit gives rise to gravitational forces.

It can also lead to an alteration in the planets' orbits. This is due to the gravitational forces produced by the interaction between the planets. A heliocentric model is a model of the solar system in which the sun is at the center and the planets orbit it. This model was first proposed by Nicolaus Copernicus, a Polish astronomer in the 16th century. He proposed this model after observing that it better explained the motions of the planets than the previous geocentric model, in which Earth was at the center and everything else revolved around it. An orbit gives rise to the gravitational force that causes a planet to continue to travel in a circle around the sun. It is also responsible for the gravitational pull between planets, which affects their orbits. A planet passing another planet in its orbit can also cause some gravitational perturbations in its orbit. This can lead to an alteration in the planets' orbits or cause their orbits to change slightly over time. The heliocentric model is currently the widely accepted theory of how our solar system is arranged. It states that the planets orbit the sun, which is a massive ball of hot gas at the center of the solar system. The sun's gravity is what keeps the planets in their orbits.

Learn more about the heliocentric model  at brainly.com/question/19757858

#SPJ4

The maximum acceleration that the student can achieve with the 1500 kg suitcase is 50N/1500kg = 0.033 m/s2.

Acceleration is the change in velocity per unit time. Acceleration is a vector quantity that has both magnitude and direction. Acceleration is divided into deceleration acceleration and acceleration acceleration. Acceleration decreases meaning the direction of acceleration is opposite to the direction of velocity.

To calculate the maximum acceleration, we can use the following equation:
Force = Mass x Acceleration. Therefore, 50N = 1500kg x Acceleration

Solving for Acceleration, we get 50N/1500kg = 0.033 m/s2.

Learn more about acceleration : brainly.com/question/20595261

#SPJ11

For the electric flux through a spherical surface is 4.3 x 10⁴ N⋅m²/C, then the net charge enclosed by the surface is μC, and for the electric flux through a cubical box 34 cm on a side is 7.5 x 10³ N⋅m²/C, the total charge enclosed by the box is μC.

The electric flux through a spherical surface is 4.3 x 10⁴ N⋅m²/C.

The net charge is Electric Flux = Charge / Surface Area,

so the net charge enclosed is 4.3 x 10⁴ / (4πr²) where r is the radius of the sphere.

Therefore, the net charge enclosed by the surface is μC.

The electric flux through a cubical box 34 cm on a side is 7.5 x 10³ N⋅m²/C.

The total charge is Electric Flux = Charge / Surface Area,

so the total charge enclosed is 7.5 x 10³ / (6a²)

where a is the length of one side of the cube.

Therefore, the total charge enclosed by the box is μC.

Learn more about electric flux here:

https://brainly.com/question/2664005

#SPJ11

The visible light spectrum is the range of wavelengths the human eye can detect, ranging from 380 to 700 nanometers.

People think of the sun, light bulbs, candles, and flames when they think of light, but visible light originates from many sources and in many hues. Other visible light sources include television and computer displays, glow sticks, and pyrotechnics.

This is why this area of the electromagnetic spectrum is known as the visible spectrum or colour spectrum. It primarily comprises of seven colours: violet, blue, green, yellow, orange, and red.

Learn more about visible light spectrum

brainly.com/question/18704022

#SPJ1

Answer:

It is the three spots where there are lines. Between 400 and 500(the two lines), between 600 and 700(the two lines), and the one line between 700 and 800.

When one stationary object is replaced by another stationary object, the change between the two objects maybe perceived as the movement of a single object. This creates an optical illusion.

An optical illusion is defined as a visual phenomenon in which the information gathered by the eye is processed in a way that results in a false perception of reality or the visual impression of seeing something that is not present or incorrectly perceiving it. It is a misinterpretation of a visual stimulus caused by the brain's ability to misjudge sensory information.

It can happen when visual information is processed in the brain, and it can create an impression of movement that isn't there. This phenomenon occurs when an object is moving or when the eyes are moving around, but it can also happen when the object being looked at is stationary.

When one stationary object is replaced by another stationary object, the change between the two objects maybe perceived as the movement of a single object. This creates an optical illusion because the visual system is misled into thinking that the object is moving.

The brain continues to process visual information even when the object is stationary, creating the impression that the object is moving. This is why an optical illusion can be used to make a stationary object appear to move or to make a moving object appear to be stationary.

Learn more about optical illusion: https://brainly.com/question/3260067

#SPJ11

Answer: The model star/planet would have to be 1,000 km away from the next closest star.

Explanation:
We need to find out the distance required for the distances in the system to be in scale.

Let's use the proportion to solve the problem:

1 m/4 × 10⁷ km = x/4 × 10¹³ km

Where x is the distance required for the distances in the system to be in scale.

Cross-multiply: 4 × 10¹³ km × 1 m = 4 × 10⁷ km × x

Simplify: 4 × 10¹³ m = 4 × 10⁷ x

Divide both sides by 4 × 10⁷ :1 × 10⁶ = x

Therefore, the distance required for the distances in the system to be in scale is 1 × 10⁶ m or 1,000 km.

So the model star/planet would have to be 1,000 km away from the next closest star.

Learn more about distance here

https://brainly.com/question/26550516

#SPJ11

The minimum angular velocity (in rpm) for swinging a bucket of water in a vertical circle without spilling any is 5.56 rpm.

The minimum angular velocity (in rpm) for swinging a bucket of water in a vertical circle without spilling any is given by the formula; Vmin=√g/R

where:

To express the answer in revolutions per minute, the radius of the circle must be converted to meters;R = 35 cm = 0.35 m

Substituting the values given above into the formula;

Therefore, the minimum angular velocity (in rpm) for swinging a bucket of water in a vertical circle without spilling any is 5.56 rpm.

Learn more about velocity: https://brainly.com/question/25749514

#SPJ11

The resulting displacement will be 3.4 km. The correct option is A.

The displacement is calculated by finding the displacement from east to west, which is 2.0 km, and subtracting the displacement from north to south, which is 1.0 km.

A student walks 1.0 kilometers due east and 1.0 kilometers due south. Then she runs 2.0 kilometers due west. The magnitude of the student's resultant displacement is closest to 3.4 km.

To begin with, we may use the Pythagorean Theorem to determine the resultant displacement's magnitude. The Pythagorean Theorem is a formula that is used to determine the length of a right triangle's sides when one is missing. This theorem is used to calculate the magnitude of the resultant displacement, which is a quantity. It's a good idea to draw a diagram to help you understand the problem.

Here's a rough sketch of the scenario: We will now apply the Pythagorean theorem in this way: The resultant displacement's magnitude is 3.4 kilometers. Thus, the correct option is A.

To know more about displacement follow

https://brainly.com/question/14637077

#SPJ11

The frequency that the bad guy hear is 12000 hz when the police car is moving with speed of 80m/s.

For more information on doppler effect kindly visit to

https://brainly.com/question/15318474

#SPJ1

EER is defined as the Energy Efficiency Ratio which is the ratio of cooling capacity in BTU/hr to the power input in watts.

The EER of the given 8000 Btu/h air conditioner is 5.33 Btu/hour per watt.

In the case of the given 8000 Btu/h air conditioner that requires a power input of 1500 W, the EER can be calculated as follows:

EER = (cooling capacity in Btu/hr) / (power input in watts)

EER = 8000 Btu/hour / 1500 W = 5.33 Btu/hour per wat.

Energy efficiency ratio (EER) is used in the USA and is defined as the system output in Btu/h per watt of electrical energy.

Coefficient of performance (COP) is the equivalent measure using SI units, which is widely used in the UK. A COP of 1.0 equates to an EER of 3.4.

To know more about power:https://brainly.com/question/11569624

#SPJ11

Yes, it is correct that when the source of blackbody radiation becomes hotter, the peak in its radiation spectrum shifts from the visible to the ultraviolet and beyond. Blackbody radiation is electromagnetic radiation emitted from a blackbody or perfect absorber. This is due to the fact that hotter objects emit shorter wavelengths of electromagnetic radiation, which correspond to higher energy photons. Therefore, when an object gets hot enough to emit mostly ultraviolet or X-ray radiation, it will no longer be visible to the unaided human eye because the human eye can only detect radiation within the visible spectrum of about 400 nm (violet) and 700 nm (red). Therefore, a blackbody that emits radiation beyond this range will no longer be seen by the unaided human eye.

For more information regarding this topic, you can click the below link

https://brainly.com/question/893656

#SPJ11

The average density of the neutron star that has a mass of about 1.5Msun and a radius of 10 kilometers rounded off to two significant figures is 5.9 × 10¹⁴ kg/cm³

The average density of a neutron star can be calculated using the following formula;`d = (3M)/(4πr³)`where `d` is the average density of the neutron star, `M` is the mass of the neutron star, and `r` is the radius of the neutron star.Using the given values in the formula, we get;`d = (3 × 1.5 × 1.989 × 10³⁰)/(4π × (10 × 10³)³)` = 5.9 × 10¹⁷ kg/m³To convert kg/m³ to kg/cm³, we can use the following conversion factor;1 m³ = 10⁶ cm³Therefore,1 kg/m³ = 10⁻³ kg/cm³So, the average density of the neutron star in kg/cm³ is;`d = (5.9 × 10¹⁷) × (10⁻³)` = 5.9 × 10¹⁴ kg/cm³Therefore, the average density of the neutron star is 5.9 × 10¹⁴ kg/cm³ (rounded to two significant figures).Answer: 5.9 × 10¹⁴ kg/cm³.

More on density: https://brainly.com/question/15700804

#SPJ11

(a) Angular momentum of Earth in a circular orbit around the sun is 2.66 × 10^40 kg m^2/s. It can be modeled as a particle. (b) The angular momentum of Earth due to its rotation around an axis through the poles is 7.07 × 10^33 kg m^2/s, modeled as a uniform sphere.

An object's angular momentum, which measures its rotating motion, is essential to many physical processes. The orbit of the Earth around the sun gives rise to the first sort of angular momentum, while the rotation of the Earth about its axis produces the second. The angular momentum of the Earth's orbit around the sun is quite large, at around 2.66 1040 kg m2/s. Given that the size and form of the Earth have little bearing on its orbit, it seems sensible to treat it as a particle for this computation. In comparison, the Earth's rotation about its own axis generates angular momentum that is only about 7.07 1033 kg m2/s in size. This kind of angular momentum is calculated using the uniform sphere's moment of inertia. In several disciplines, including astronomy and geophysics, the Earth's angular momentum is a crucial number.

learn more about Angular momentum here:

https://brainly.com/question/29897173

#SPJ4

Answer:

Explanation:

o calculate the current I, we can use Ohm's Law which states that I = V/R, where V is the total voltage across the resistor and R is the resistance of the resistor.

a) The total voltage across the resistor can be found by adding the voltage of the two batteries in series, which gives a total voltage of 8V + 4V = 12V.

So, I = V/R = 12V/4Ω = 3A.

b) The potential difference Uba is simply the voltage difference between the two batteries in the series combination, which is 8V - 4V = 4V.

c) When switch S is open, the circuit is broken and the potential difference Uba' becomes equal to the voltage of the 8V battery. So, Uba' = 8V.