the average speed of a car that travels a distance of 240 km is three hours

Answer:

Explanation:

When an object moves through a fluid, like air, water or oil, the object experiences a resistance to flow; this is, to pass through the fluid.

This resistance force is the fluid friction.

In few words, fluid friction is a force that opposes the motion of the objects through the fluid.

Then, in the abscence of fluid friction, all objects falling accelerate at the gravity acceleration.

Answer:

Those parts have become vestigial

Explanation:

Organisms have few parts that are not useful to them because those parts in them have become vestigial.

When an organism has a part is no more using, it relates to the evolutionary history of such organism.

Answer:

Those parts have become vestigial

Explanation:

Organisms have a few parts that are not useful to them because those parts in them have become vestigial.

When an organism has a part that is no more used, it relates to the evolutionary history of such organism.

These parts are called vestigial body parts.

They are not needed for the survival of an organism again and they can do without them.

At a certain point in time, those parts might be very vital to the sustenance of such organisms.

With time, those parts become useless and redundant.

To compare the brightness of light bulbs, you should look for the luminous flux in lumens on their labels, as this measures the perceived power of light by the human eye, offering a more accurate representation of brightness than wattage alone.

To compare the brightness of light bulbs for sale in a store, you should look on the labels to see how they are rated in terms of luminous flux, which is measured in lumens (lm). The luminous flux is a measure of the perceived power of light by the human eye. Energy-saving light bulbs like compact fluorescent lamps and LED bulbs provide more luminous flux for a given use of electricity, meaning they have higher luminous efficacy, represented in lumens per watt. When replacing an old incandescent bulb with an energy-saving one, it is important to compare lumens to ensure the same level of brightness is achieved.

Traditionally, people have been accustomed to associating the brightness of a bulb with its power consumption in watts due to the prevalence of incandescent bulbs. However, as technology has advanced, the importance of comparing lumens, rather than just wattage, has become clear for a more accurate representation of a bulb's light intensity. A higher wattage does not necessarily mean more visible light, since not all electrical power is converted into visible light. Also, different types of bulbs convert electricity to light with varying efficiencies.

Note: The efficiency of a light bulb, which is the fraction of its total light output that falls within the visible range, is never 100% due to the nature of thermal sources and the distribution of emitted wavelengths.

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Answer:

JJ. Thomson-  electrons mixed in a positive sphere

Ernest Rutherford- central nucleus

Democritus and Dalton- indivisible sphere

Explanation:

Hope this helps!

Ernest Rutherford discovers the Concept of nucleus. J.J Thompson contributes to the Discovery of electrons. Dalton gives the concept of the Indivisibility of atoms.

A. Ernest Rutherford: Contribution - Concept of the nucleus. Rutherford's famous Gold Foil Experiment led to the discovery that most of the atom's mass and positive charge are concentrated in a small, dense nucleus at the center of the atom.

B. J.J. Thompson: Contribution - Discovery of electrons. J.J. Thompson discovered electrons using cathode ray tubes and proposed the "Plum Pudding Model," which suggested that atoms contained negatively charged electrons embedded in a positively charged material.

C. Dalton: Contribution - Indivisibility of atoms. Dalton's Atomic Theory proposed that matter is made up of indivisible and indestructible particles called atoms, which combine to form compounds in fixed ratios.

Therefore, Ernest Rutherford discovers the Concept of the nucleus. J.J Thompson contributes to the Discovery of electrons. Dalton gives the concept of the Indivisibility of atoms.

To know more about the electron and nucleus:

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The complete question is:

Match column A (name of the Scientists) with column B (their contributions towards the understanding of the atomic structure).

Column A                  Column B

A. Ernest Rutherford  1. Indivisibility of atoms

B. J.J Thompson          2. Concept of nucleus

C. Dalton                  3. Discovery of electrons

Answer:

32.71 L

Explanation:

We can solve this question using Boyle's law of ideal gas. The law states that the volume and pressure are inversely proportional when the temperature is constant. At first, the volume is 18L (V1) and the pressure is 87.6 kPa(P1). Then the pressure changed into 48.2 kPa(P2). We are asked to find the volume(V2).

The calculation will be:

P1 * V1= P2 * V2

87.6 kPa  *18L = 48.2 kPa * V2

V2=  87.6 kPa  *18L / 48.2 kPa

V2=32.71 L

Answer:

the first one is: Neptune

second one: Saturn

third one: Uranus

fourth one: Jupiter

Explanation:

The classification is as follows:

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Answer:

[tex]-1.74\cdot 10^{-6} C[/tex]

Explanation:

The electron is the particle that rotates around the nucleus of the atom; it has a negative electric charge equal to :

[tex]e=-1.6\cdot 10^{-19}C[/tex]

which is known as fundamental charge.

For an object containing N excess electrons, the total charge of the object is

[tex]Q=Ne[/tex]

In this problem, the number of excess electrons in the object is:

[tex]N=1.09\cdot 10^{13}[/tex]

Therefore, by plugging it the numbers, we can find the value of Q, the total charge of the object:

[tex]Q=(1.09\cdot 10^{13})(-1.6\cdot 10^{-19})=-1.74\cdot 10^{-6} C[/tex]

Answer:

F = 431671.31 [N]

Explanation:

This problem can be solved using the work and energy theorem, which tells us that the initial mechanical energy (potential energy + kinetic energy) plus the sum of the work from the initial position to the end will be equal to the final mechanical energy.

[tex]E_{M1}+W_{1-2}=E_{M2}\\0.5*m*v_{1}^{2}+W_{1-2}=0.5*m*v_{2}^{2}[/tex]

As the train stops at the end, the speed at Point 2 is equal to zero,so we can determine the work, we first convert the speed from [km/h] to meters per second.

[tex]250[\frac{km}{h}]*1[\frac{h}{3600s} ]*1000[\frac{m}{1km} ]\\= 69.44[\frac{m}{s} ][/tex]

[tex]0.5*(8.63*10^{5})*(69.44)^{2}+W_{1-2}= 0.5*(8.63*10^{5})*(0)^{2}\\W_{1-2}=-2080.66*10^6[J][/tex]

The negative sign means that the work is done in the opposite direction to the movement.

Knowing the work we can calculate the force, since an initial input data is the distance

W = F * d

F = W / d

F = (2080.66*10^6) / 4820

F = 431671.31 [N]

Answer:

the changing of the structure of a gene, resulting in a variant form that may be transmitted to subsequent generations, caused by the alteration of single base units in DNA, or the deletion, insertion, or rearrangement of larger sections of genes or chromosomes

Explanation:

Answer: Option B

The wavelength for a radio wave with a frequency of  2 × 10⁴ Hz is

1.5 × 10⁴ m.

Explanation:

Wavelength is the measure of distance between two successive crests or troughs in a standing wave. Also wavelength can be measured as the ratio of velocity of light to frequency. It is like this because wavelength is inversely proportional to the frequency.

[tex]Wavelength =\frac{c}{frequency}[/tex]

As c = 3 × 10⁸ m/s and the frequency is 2 × 10⁴ Hz, then the wavelength will be

[tex]Wavelength =\frac{3*10^{8} }{2*10^{4} } =1.5*10^{4} m[/tex]

So, the wavelength for a radio wave with a frequency of  2 × 10⁴ Hz is

1.5 × 10⁴ m.

Answer: b

The force on the rifle equals the force on the bullet. Yet, acceleration depends on both force and mass. The bullet has a greater acceleration due to the fact that it has a smaller mass. Remember: acceleration and mass are inversely proportional

Answer:

Acceleration of gravity=[tex]9.8m/s/s[/tex]

Explanation:

Newton's Second Law-acceleration is proportional to the net force acting on an object.

All objects usually free fall at the same acceleration of [tex]9.8m/s/s[/tex]-this regardless of their mass. This acceleration is known as acceleration of gravity.

Answer:

56.25J

Explanation:

Kinetic energy = 1/2 mv^2

Where m = mass

v = velocity

Given m = 4.50kg

v = 5.00m/s

Kinetic energy = 1/2 x 4.50 x (5.00)^2

= 1/2 x 4.50 x (5.00 x 5.00)

= 1/2 x 4.50 x 25

Multiply through

= 112.5/2

= 56.25J

Answer:

Physical properties are different from chemical properties of a substance. The main difference between physical and chemical properties is that physical properties can be observed without changing the chemical composition of a substance whereas chemical properties can be observed by changing the chemical composition of a substance.

Explanation:

The differences are:

1. Physical change is easily reversible while chemical change is not easily reversible

2. Physical change forms no new substance. while chemical change forms new substance

3. In Physical change there is no change in the mass of a substance involved while In chemical change, there is a change in the mass of the substance involved.

4. Physical change does not involve great heat. while chemical change involves considerable amount of heat.

The Similarities are :

1. They can be both reversible.

2. Heat is involved

3. They both involve reasonable amount of substance or matter.

Physical properties exhibit physical changes such as:

boiling and melting point of a substance, density, hardness, malleability, crystalline form and some properties that can be detected by our sense organ, such as taste, color and odor.

While chemical properties occur when matter or substance undergoes a change to form another new substance. For example : rusting of iron and burning of wood.

The differences are:

1. Physical change is easily reversible while chemical change is not easily reversible

2. Physical change forms no new substance. while chemical change forms new substance

3. In Physical change there is no change in the mass of a substance involved while In chemical change, there is a change in the mass of the substance involved.

4. Physical change does not involve great heat. while chemical change involves considerable amount of heat.

The Similarities are :

1. They can be both reversible.

2. Heat is involved

3. They both involve reasonable amount of substance or matter.

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Answer: Solids

Explanation: Solids have very little movement and the particles have barely enough movement to vibrate. We can't see it but the particles are indeed vibrating. Solids have the least amount of kinetic energy which is moving energy.

Answer:

B

Explanation:

the battery isn't chemical energy so any answer saying that you can cross out and that leaves you with B

Answer:150N

Explanation:

Total mass=mass of skate board + mass of rider

Total mass(m)=46kg + 4kg

Total mass(m)=50kg

Acceleration(a)=3m/s^2

Force(f)=mass x acceleration

Force=50 x 3

Force=150N

To accelerate the skateboard and rider at 3 m/s², a force of 150 N is required.

The force required to accelerate a 4-kg skateboard and its 46-kg rider at 3 m/s² can be calculated using Newton's second law, which states that Force = mass x acceleration.

Applying the formula, the total mass is 4 kg + 46 kg = 50 kg.

Therefore, the force required is 50 kg x 3 m/s² = 150 N.

Answer:

V=[tex]3204m/s[/tex]

Direction is normal to the incline

Explanation:

This question tests on projectile motion.

First, calculate the acceleration of the missile.

Incline=55º,Distance=23500m, t=10seconds.

Horizontal motion of projectile

[tex]x=V_xt+0.5a_xt\\23000Cos55\textdegree=1350Cos25\textdegree\times10.20+0.5a_x(10.20)^2\\a_x=19.2m/s^2[/tex]

Final velocity

[tex](V_x)\prime=V_x+a_xt=1350Cos25\textdegree+19.2\times10.20=1419m/s[/tex]

The vertical motion of the missile can be calculated as:

[tex]23500 Sin55.0\textdegree =1350Sin25\textdegree\times10.2+0.5a_y\times10.2^2\\a_y=258.2m/s^2[/tex]

Final Velocity is:

[tex](V_y)\prime=V_y+a_yt=1350Sin25\textdegree+258.2\times10.20=3204m/s[/tex]

Combining both we get

[tex]V=\sqrt(V\prime x^2+V\primey^2)=3504.2m/s[/tex]

*Misile's motion is normal to the 55º incline.

The potential difference across a resistor measured using a voltmeter takes into account the internal resistance of the voltmeter, altering the circuit dynamics. Calculations involve finding the equivalent resistance of the voltmeter-resistor parallel combination and applying Ohm's law accordingly.

When measuring the potential difference across a resistor in a series circuit using a voltmeter, it is essential to consider the internal resistance of the voltmeter itself, as it is placed in parallel with the resistor being measured. In this case, with resistors of 1000 ohm and 2000 ohm connected in series to a 100V supply and a voltmeter of 4000 ohm internal resistance connected across the 1000 ohm resistor, the circuit's behavior is modified. First, calculate the total series resistance, which is 3000 ohms. This gives a total current (I) of 100V/3000 ohms = 0.0333 A. The voltage across the 1000 ohm resistor without the voltmeter would be V = IR = 0.0333A × 1000 ohm = 33.3V.

However, the presence of the voltmeter alters this calculation by creating a parallel circuit with the 1000 ohm resistor and the voltmeter's 4000 ohm resistance. The equivalent resistance of this parallel circuit can be calculated with 1/Req = 1/R1 + 1/R2, leading to an equivalent resistance of 800 ohms. Applying Ohm's law again for the modified circuit gives a slightly different current, and subsequently, the potential difference can be calculated.

Answer:

When it is cloudy, many of the sun’s rays never reach the Earth. It leads to cooler temperatures.

Explanation:

During the day, the sun warms the earth. When the sky is clear, more heat reaches the earth's surface . This leads to warmer temperatures.

However, when the sky is cloudy, a few drops of clouds reflect some of the sun's rays. As a result, less solar energy can reach Earth's surface, causing Earth to heat up more slowly. This leads to cooler temperatures.

If cloudy skies are forecast when forecasting daytime temperatures, expect lower temperatures than you would expect if clear skies were forecast.

Similarly, cloud cover at night has the opposite effect. When the sky is clear, the heat emitted from the earth's surface freely escapes into space, resulting in cooler temperatures.

However, when there are clouds, some of the heat from the earth's surface is captured by the clouds and returned to the earth. As a result, temperatures drop more slowly than when the sky is clear.

Final answer:

Cloud cover influences Earth's temperatures, with thick clouds leading to cooler days by blocking sunlight and warmer nights by trapping heat. Low clouds primarily cool the Earth while high clouds can contribute to warming due to trapping of infrared radiation. This results in different temperature outcomes depending on cloud type and time of day.

Explanation:

When it is cloudy, many of the sun’s rays are either reflected or absorbed by clouds, which can significantly influence temperature conditions on Earth. During the day, thick clouds can prevent the sun's energy from warming the Earth's surface as effectively, leading to cooler daytime temperatures. Conversely, at night, these same clouds can act as an insulating layer, trapping longwave radiation that is emitted from the Earth's surface and preventing it from escaping into space, resulting in warmer nighttime temperatures.

Furthermore, cloud cover affects the radiation balance of Earth differently based on the type of clouds. Low clouds generally have a net cooling effect since they reflect more sunlight back into space. On the other hand, high cirrus clouds tend to have a net warming effect by trapping more infrared radiation. This dynamic leads to a complicated system of cloud feedbacks that influence global temperature patterns.

In summary, clouds play a critical role in the Earth's climate system by influencing how much of the sun's energy is absorbed or reflected, and how much earthly heat is retained or released, thereby affecting the overall temperature experienced at Earth's surface.

Answer:

1543 J

Explanation:

The work done by a force when moving an object is given by the equation:

[tex]W=Fd cos \theta[/tex]

where:

F is the magnitude of the force applied on the object

d is the displacement of the object

[tex]\theta[/tex] is the angle between the direction of the force and of the displacement

For the  cart pushed in this problem, we have:

[tex]F=120 N[/tex] is the force applied by the man

[tex]d=20 m[/tex] is the displacement of the cart

[tex]\theta=50^{\circ}[/tex] is the angle between the directions of the force and of the displacement

Solving for W, we find the work:

[tex]W=(120)(20)(cos 50^{\circ})=1543 J[/tex]

Answer:

See the explanation below, and the different answers

Explanation:

It is important to clarify that the mass is always preserved, that is, it does not vary regardless of the location of the person, whether the moon, Saturn, Mars. The value that changes is the weight, due to the gravity of each planet.

On Earth

m = 86[kg]

w = m * g

where:

g = gravity acceleration = 9.81[m/s^2]

w = weight = [N]

w = 86 * 9.81

w = 843.66 [N]

On the Moon

m = 86[kg]

w = m * g

where:

g = gravity acceleration * (1/6) = 9.81 * (1/6) = 1.635 [m/s^2]

w = weight = [N]

w = 86 * 1.635

w = 140.61 [N]

The mass of the man would still be 86kg, but his weight on the moon would be approximately 14.33kg.

To determine the mass and weight of an 86kg man on the moon, where the gravitational field is one-sixth that of Earth's, we can use the equation:

Weight = mass x gravitational field

Since the mass of the man is 86kg, the weight on the moon would be:

Weight = 86kg x (1/6) = 14.33kg

Therefore, the mass of the man would still be 86kg, but his weight on the moon would be approximately 14.33kg.

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Answer: Quantum programming is the process of assembling sequences of instructions, called quantum programs, that are capable of running on a quantum computer. Quantum programming languages help express quantum algorithms using high-level constructs.

Explanation:

Final answer:

Quantum programming involves creating algorithms and software for quantum computers, utilizing qubits and principles like superposition and entanglement. It requires knowledge of quantum mechanics and is supported by programming languages like Q# and Qiskit.

Explanation:

Quantum Programming

Quantum programming is a field within computer science that focuses on the development of algorithms and software for quantum computers. These computers leverage the principles of quantum mechanics to process information in ways that traditional computers cannot. Quantum programming often involves the use of quantum bits or qubits, which, unlike classical bits, can exist in multiple states simultaneously. This state is known as superposition, and it allows quantum computers to perform certain computations much faster than classical computers. Another key concept in quantum computing is entanglement, which enables qubits that are entangled to be correlated with one another even when separated by large distances.

Quantum programming languages, such as Q# by Microsoft and Qiskit by IBM, provide frameworks for developers to write programs that can run on quantum computers. The field is highly interdisciplinary, drawing from areas such as physics, mathematics, and computer science.

Answer:10m/s

Explanation:

M=mass of gun=4kg

U=recoil velocity of gun

m=mass of bullet=0.1kg

V=velocity of bullet=400m/s

M x U=m x V

4 x U=0.1 x 400

4xU=40

Divide both sides by 4

(4xU)/4=40/4

U=10m/s

Recoil velocity=10m/s

Answer:

meters or meter...

Explanation:

....

The kinetic energy of the body in definitive position is 4.24 J.

Explanation:

As per the work energy theorem, the work done on any system or object to move it from one position to another is equal to the change in kinetic energy of the object. In this case, the body weighing 2 kg is moved over an horizontal surface for a distance of 75 cm. As there will be frictional force acting on the body while moving over the surface. This frictional force multiplied by the distance the object is moved will give the work done on the body.

Frictional force = Coeffficent of friction × Normal force.

As the weight of the body is 2 kg, the normal force acting on it will be mass multiplied with acceleration due to gravity.

Frictional force = - 0.8×9.8 × 2 =-15.68 N

So the work done will be the product of frictional force with the displacement of 75 cm or 0.75 m.

Work done =  Frictional force × Displacement

Work done = -15.68×0.75 = -11.76 J.

So the work is done by the object.

If the kinetic energy of the body at starting is 16 J, then the kinetic energy of the body at definitive position will be obtained as below.

Work done = change in kinetic energy

-11.76 J = Final kinetic energy-16 J

Final Kinetic energy = - 11.76+16

Final kinetic energy = 4.24 J

Thus, the kinetic energy of the body in definitive position is 4.24 J.

Answer:

9.80665 is the value in meters per second squared

Explanation:

1/2mv^2 = mgh

1/2×3×25^2 = 3×9.8×h

937.5 =29.4h

29.4h/29.4 = 937.5/29.4

h=31.89 m

Answer:I don't see any

Explanation:

Answer: (B)  The pancreas is a part of the cardiovascular system. The heart and your circulatory system is a part of it (which includes blood and your veins/arteries).

Explanation: