by what are isotopes identified?

A.mass numbers
B.atomic masses
C.atomic mass units
D.average atomic masses

Answer:

The answer is:

c) 9 times

Explanation:

20/60= 3 x 3=9

Answer:

Every magnet has both a North and a South pole. When you place the North pole of one magnet near the South pole of another magnet, they are attracted to one another. When you place like poles of two magnets near each other (North to North or South to South), they will repel each other.

Answer:

All magnets, regardless of their shape or application, must have two poles, the north pole (N) and the south pole (S), which are called magnetic poles.

Explanation:

Magnets are ferromagnetic materials that have the property of attracting or repelling other magnets. In addition, it is characteristic for materials of this nature (ferromagnetic) to be strongly magnetized in the presence of a magnetic field.

All magnets, regardless of their shape or application, must have two poles, the north pole (N) and the south pole (S), which are called magnetic poles. Another important characteristic of magnets is the inseparability of the magnetic poles, that is, it is not possible to find a magnet with only the north pole or only with the south pole. Thus, when a magnet is broken, it will give rise to two new magnets and the polarity of these new magnets will depend on the way in which it partitioned.

Answer:

(i) 140 N/m

(ii) 28 m/s²

Explanation:

(i)

At the top of the jump, the bungee jumper has gravitational potential energy.

At the bottom of the jump, the bungee jumper has elastic potential energy.

mgh = ½ kx²

(60 kg) (9.8 m/s²) (31 m) = ½ k (31 m − 15 m)²

k = 140 N/m

(ii)

At the bottom of the jump:

∑F = ma

kx - mg = ma

(140 N/m) (31 m − 15 m) − (60 kg) (9.8 m/s²) = (60 kg) a

a = 28 m/s²

The spring constant of the bungee cord is approximately found to be 36.75 N/m, and the maximum acceleration experienced by the jumper is approximately 7.6 m/s^2.

To answer the first part of your question: (i) the spring constant of the bungee cord, we will use Hooke's law which states: F = kx. Here, 'F' is the force, 'k' is the spring constant, and 'x' is the distance stretched. Because the bungee jumper is in free fall, the force acting on her is equal to her weight, so F = m*g = 60kg * 9.8m/s^2 = 588N. The distance stretched would be the total distance fallen minus the original length of the cord, so x = 31m - 15m = 16m. Hence, the spring constant k = F/x = 588N / 16m = 36.75 N/m.

For the second part: (ii) the maximum acceleration experienced by the jumper, when the jumper is at the bottom of the fall, the potential energy has completely converted to elastic potential energy. Thus, .5*k*x^2 = m*g*h. Substituting the found values of k and h (total distance), you can solve for the acceleration, which is approximately 7.6 m/s^2.

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Final answer:

Real images are formed by convergence of light rays and can be projected onto a screen, while virtual images are formed by apparent divergence of light rays and cannot be projected onto a screen. You can tell if an image is real or virtual by its position relative to the lens/mirror.

Explanation:

Differences between Real and Virtual Images:

A real image is formed by the convergence of actual light rays and can be projected onto a screen. It is always inverted. On the other hand, a virtual image is formed by the apparent divergence of light rays and cannot be projected onto a screen. It is usually upright.

Determining if an Image is Real or Virtual:

By looking at an image, you can determine whether it is real or virtual based on its characteristics. If the image is formed on the opposite side of the lens/mirror from the object, it is virtual. If the image is formed on the same side as the object, it is real.

Answer:

The answer is A.  Spokespersons are paid for their testimony.  Psueoscience is NOT a real science.

Explanation:

Explanation:

Refracting telescopes have an optical system consisting of a set of lenses that have the property of deflecting (refracting) the light that passes through them.

In this way, the images captured from distant objects converge on a point in the focal plane of the telescope.

However, the main disadvantage of this type of telescope is the chromatic aberration, which produces annoying color halos (mainly red and blue) around the image.

It should be noted that the chromatic aberration occurs because the different wavelengths that make up the light (the colors of the light) that passes through the objective lens deviate (refract) in different ways, causing them not to focus on the same point. For example,  blue wavelengths are focused before the green wavelengths and these before the red ones. And this problem is stronger the shorter the focal length of the lens is.

Answer:

C

Chromatic aberration affected:

spectrographs

radio telescopes

refracting telescopes

reflecting telescopes

Answer:625

Explanation:

The gravitational force between two object sets is onversly proportional to the square of the distance between the objects.if the distance reduces by a factor of 5 the force will increase by a factor of 5^2=25

The changing force of attraction between them is 625 Newtons

The answer is option D.

The gravitational force between two object sets is inversely proportional to the square of the distance between the objects. If the distance reduces by a factor of 5 the force will increase by a factor of 5^2=25

The gravitational force is a pressure that draws any two objects with mass. We call the gravitational pressure attractive as it usually attempts to pull masses together, it in no way pushes them aside. In reality, every object, including you, is pulling on every other item inside the complete universe.

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D

hydrosphere-- anything to do with water

geosphere -- the rocks and soil

topsoil (geosphere) is eroded by rainwater(hydrosphere)

Answer:

D

Explanation:

Force is a vector, it has direction, it can move objects and it was well described with laws by physicist Isaac Newton by which the units of force were named Newtons (N).

Hope this helps.

r3t40

1 Newton is the force that accelerates 1 kg of mass at the rate of 1 m per sec^2.

In the cgs system, the unit of force is the dyne. That's the force that accelerates 1 gram of mass at the rate of 1 cm per sec^2.

So 1 Newton of force is 100,000 dynes.

Answer: I think, the number of oscillations in a given period of time.

Explanation: Well I guess because in a period time is known as the rate of occurrence of the wave. Hope this helps!

To determine the frequency of a wave you must measure by counting the number of high points of waves that pass the fixed point in 1 second or some other time period.

Wave frequency is the number of waves that pass a fixed point at a particular time. The SI unit of wave frequency is hertz (Hz). Here, 1 hertz corresponds to a wave passing through a fixed point every second. High frequencies have more energy than low frequencies of the same amplitude.

The relationship between wavelength and frequency is called the reciprocal because the higher the frequency, the shorter the wavelength.

In addition to the defined speed, each wave has a frequency. This is the number of wavelengths that pass a point per second. Frequency is measured in Hertz (wavenumber per second).

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Answer:

4200 kJ

10 kg/min

Explanation:

70 kW means 70 kJ per second.  So in a minute, the amount of heat generated at the brake is:

70 kJ/s × 60 s/min = 4200 kJ

Heat = mass × specific heat capacity × increase in temperature

4200 kJ = m × 4.184 kJ/kg/C × 100 C

m = 10 kg

So every minute, 10 kg of water is heated.  So the mass flow is 10 kg/min.

Answer:

81.1 m

Explanation:

Given:

x₀ = 0 m

y₀ = y = 0 m

v₀ₓ = 29.5 cos 33.0° m/s

v₀ᵧ = 29.5 sin 33.0° m/s

aₓ = 0 m/s²

aᵧ = -9.8 m/s²

Find:

x

First, find the time it takes to land.

y = y₀ + v₀ᵧ t + ½ aᵧt²

0 = 0 + (29.5 sin 33.0) t - 4.9 t²

t = (29.5 sin 33.0) / 4.9

t = 3.28 s

Now in the x direction:

x = x₀ + v₀ₓ t + ½ aₓt²

x = 0 + (29.5 cos 33.0) (3.28) + 0

x = 81.1 m

The outfielder was 81.1 meters away.

Answer:

Sedimentary

Explanation:

The process by which rock fragments are moved from the source is Sedimentary.

Answer:

Sedimentary

Explanation:

a process by which rock fragments are moved from the source

Answer:

Explanation:

Stokes' theorem relates a surface integral of a the curl of the vector field to a line integral of the vector field around the boundary of the surface.

Final answer:

Stoke's Theorem relates the integral of differential forms over the boundary of a manifold to the integral of its exterior derivative over the manifold itself, commonly used in vector calculus and differential geometry.

Explanation:

Stoke's Theorem in mathematics is a statement about the integration of differential forms on manifolds, which both simplifies and generalizes several theorems from vector calculus. According to Stoke's Theorem, the integral of a differential form over the boundary of a manifold is equal to the integral of its exterior derivative over the manifold itself. Mathematically, it is expressed as ∫₋Σdω = ∫Σω, where dω is the exterior derivative of the form ω, Σ is the manifold, and ∂Σ is its boundary.

It is a powerful tool in both theoretical and applied mathematics, and in physics, particularly in the fields of electromagnetism and fluid dynamics. In simple terms, it establishes a relationship between the flow of a vector field through a surface and the behavior of the vector field along the boundary of that surface. This theorem is used in the analysis of vector fields and is fundamental in the area of differential geometry.

Answer:

A. Exposing a crystal of a semiconductor to heat or light starts displacing valence electrons, which then move throughout the crystal.

Explanation:

A semiconductor has several properties, the main two are:

1. Under no special treatment and polarization conditions, there can't be current flow through it due to the high resistance.

2. The semiconductor material can have special change in its structure (excess of electron or holes), to be conductive under certain polarization situations.

Final answer:

The correct answer is A, as semiconductors conduct electricity when valence electrons are displaced by heat or light, and these electrons move throughout the crystal. The other options are incorrect; semiconductors are not classified by low resistance, both free electrons and holes are charge carriers in semiconductors, and gold and silver are conductors, not semiconductors.

Explanation:

The correct answer to which of the following is true of semiconductors is A. Exposing a crystal of a semiconductor to heat or light starts displacing valence electrons, which then move throughout the crystal. Semiconductors like silicon have a filled valence band and an unfilled conduction band, with a relatively small energy gap between the two. When moderate amounts of energy, such as heat or light, are provided, electrons can move from the valence band to the conduction band, becoming free to move throughout the crystal and thereby conduct electricity.

Option B is incorrect because semiconductors are not classified by their low resistance, but by their ability to conduct electricity under certain conditions, such as temperature or doping with impurities. Option C is not true, as both free electrons and holes act as charge carriers in a semiconductor. Lastly, option D is incorrect because gold and silver are conductors, not semiconductors. They are known for their excellent ability to conduct electricity due to their many free electrons.

Semiconductors' unique properties are utilized extensively in the creation of integrated circuits (IC) and other electronics, including diodes and transistors that are fundamental to modern technology.

We know that frequency is an inverse value of time [tex]f=\dfrac{1}{t}[/tex] this implies that time is the inverse value of frequency [tex]t=\dfrac{1}{f}[/tex].

Now since f is 40kHz, we can calculate period or duration for that matter time.

[tex]t=\dfrac{1}{40\mathbf{kHz}}=0.000025\mathbf{s}=25\mathbf{\mu s}[/tex]

Hope this helps.

r3t40

The goods and the services make up the basis of every economy. The goods can simply be defined as merchandise or possessions. The services can be defined as the actions through which help is provided, or work is done for someone else. Example of goods are the food and furniture, with the food being crucial for the survival of the people, while the furniture is an essential part of every home and its practicality and decor. Examples of services are teaching and car repairing. The teaching is crucial for the development of the societies, as through it the people get education, while the repairing of cars is very important as lot of people have them, can not afford to buy new ones all the time, and they need for their daily movement over longer distances.

Of Hectogram, Dekagram, Decigram, and Microgram, the largest unit is the Hectogram, as it equals 100 grams which is much larger than the other options.

Among the options you provided: Hectogram, Dekagram, Decigram, and Microgram, the largest unit is the Hectogram. Here is why: measuring units in the metric system increase or decrease by powers of 10. A hectogram equals 100 grams which is significantly larger than a Dekagram (10 grams), a Decigram (0.1 gram), and a Microgram (0.000001 gram).

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Explanation:

8 m × (1000 mm / m) = 8000 mm

The electrostatic force is both attractive and repulsive and acts over long distances, while the strong nuclear force is a very powerful attractive force acting only over short distances within the atomic nucleus. The strong nuclear force is stronger than the electrostatic force and is responsible for the stability of the nucleus by binding protons and neutrons together.

Comparing the electrostatic force to the strong nuclear force within the nucleus of an atom, several key differences emerge. The electrostatic force can act over very large distances and can be either attractive or repulsive, depending on the charges involved. In contrast, the strong nuclear force is an extremely powerful attractive force that acts only over incredibly short distances, approximately 10-15 meters, which is about the scale of the atomic nucleus. This force is responsible for holding protons and neutrons together within the nucleus, overcoming the electrostatic repulsion between like-charged protons.

Examining the available choices:

The most accurate way to characterize these forces is that the strong nuclear force is a short-range but much stronger force, crucial for the stability of nuclei, while the electrostatic force, governed by Coulomb's law, has a longer range and is comparatively weaker than the strong nuclear force, but plays a critical role in interactions over larger distances and molecular bonding.

Answer:

D. It prevents anything from going wrong during the experiment.

Explanation:

One reason that writing clear step-by-step procedures is important because it prevents anything from going wrong during the experiment.

Answer:

43.1

Explanation:

Mv=Mv

0.07*800=1.3*V

V=56/1.3

V=43.07

then 43.1

Answer:

[tex]v = 4.28 m/s[/tex]

[tex]Impulse = 5.57 kg m/s[/tex]

Explanation:

Here we can say that bullet + block system is an isolated system and there is no external force on it

So Net momentum of bullet + block system will remains conserved

So we will say

[tex]m v_o = (M + m) v[/tex]

so we will have

[tex]v = \frac{m}{M + m} v_o[/tex]

[tex]v = \frac{0.007 (800)}{1.3 + 0.007}[/tex]

[tex]v = 4.28 m/s[/tex]

Also in order to find the impulse on the block we know that

impulse = change in the momentum of the block

[tex]Impulse = m(v_f - v_i)[/tex]

[tex]Impulse = 1.3(4.28 - 0)[/tex]

[tex]Impulse = 5.57 kg m/s[/tex]

Answer:

B

A meteorologist studies weather, such as a weather forecaster. :)

Answer: B. Weather

Explanation: A meteorologist studies weather, and can be a weatherman.

A transformer consists of two loops of wire with an AC current going through the "primary" loop inducing a voltage, and therefore a current, in the "secondary" loop.

The ratio of the induced voltage in the secondary loop to the voltage in the primary loop is equal to the ratio of the number of turns in the secondary loop to the number of turns in the primary loop.

A step-up transformer is designed to make the induced voltage in the secondary loop greater than the voltage in the primary loop. This requires the primary loop to have fewer turns than the secondary loop.

Choice C

A step-down voltage transformer changes incoming voltage to a lower voltage by having a different number of turns in the primary than in the secondary winding.

A step-down voltage transformer has a different number of turns in the primary than in the secondary winding, which allows it to change the incoming voltage to a lower voltage. Transformers are devices that work with alternating current (AC) voltages, where the current direction and voltage polarity alternates back and forth. The number of windings in the primary and secondary coils determine whether a transformer is a step-up or step-down transformer.

Apply Newton's second law of motion:

F = ma

F = force, m = mass, a = acceleration

Given values:

m = 500kg

a = 5m/s²

Plug in and solve for F:

F = 500(5)

F = 2500N

Choice D

The force that will accelerate a 500kg object at a rate of 5m/s2 is calculated using Newton's second law of motion. By applying the formula Force = Mass x Acceleration, we find that the force needed is 2500 N (Option D).

The force that will accelerate a 500kg object at a rate of 5 m/s2 is calculated using Newton's second law, also known as the law of motion. This law states that the force exerted on an object is equal to the mass of the object multiplied by the acceleration of the object. In this case, we can use this formula: Force = Mass x Acceleration. Substituting the values given, we have Force = 500kg x 5m/s2, which gives us 2500 Newton (N). So, option D (2500 N) is the correct answer.

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Answer:

closely molecules materials are the best compared to far apart molecule materials

Explanation:

closely molecules materials are easily charged and loose charge slowly while far apart molecules materials get charged slowly wand loose charge faster

Answer:Explained

Explanation:

Engineers at a technology company should know about the structure of different metals because a battery works on chemical reaction occurring inside in it.If a wrong metal is chosen then chances of spilling or even explosion can occur. Moreover knowledge of metal may help them to make battery light and tougher which can withstand an elevated temperature.

The conversion of 3.5 inches to centimeters using the conversion rate of 1 inch equals 2.54 cm results in a value of 8.89 cm.

To convert the measurement from inches to centimeters, we need to use the conversion rate given in the question, i.e., 1 inch equals 2.54 centimeters. In this case, since we have a measurement of 3.5 inches, we multiply 3.5 by 2.54 to find the measurement in centimetres.

So, 3.5 inches * 2.54 cm/inch = 8.89 cm. Therefore, the measurement of 3.5 inches in centimeters is equal to 8.89 cm which corresponds to option B.

So option B.8.89 cm is the correct answer.

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1. The force of gravity as a satellite orbits a planet.

According to Newton's first law, an object  stays at rest (or continue its motion with constant velocity) if the net force acting on it is zero.

This means that in order to have a circular motion (where the velocity changes, because the direction of motion constantly changes), we must have a net force acting on the object. This force is called centripetal force, and it always acts towards the centre of the circular trajectory.

An example of circular motion is a satellite orbiting a planet - in this case, the force of gravitational attraction between the planet and the satellite acts as centripetal force, keeping the satellite in circular motion.

2.  13.7 m/s

The centripetal force acting on an object is given by:

[tex]F=m\frac{v^2}{r}[/tex]

where

v is the speed of the object

m is its mass

r is the radius of the trajectory

In this situation, the centripetal force is provided by the frictional force, which is given by

[tex]F_f = \mu mg[/tex]

where

[tex]\mu[/tex] is the coefficient of friction between the tire and the road

g = 9.8 m/s^2 is the acceleration due to gravity

Equalizing the two forces,

[tex]\frac{v^2}{r}=\mu g[/tex]

where we have:

r = 55.0 m is the radius of the track

[tex]\mu=0.350[/tex] is the coefficient of friction

Solving for v, we find the maximum speed that the car can substain:

[tex]v=\sqrt{\mu g r}=\sqrt{(0.350)(9.8)(55.0)}=13.7 m/s[/tex]

3. 1.2 N, toward the center of the circle

In this situation, the tension in the string provides the centripetal force that keeps the ball in circular motion, so we can write:

[tex]T=m\frac{v^2}{r}[/tex]

where

T is the tension in the string

m = 0.015 kg is the mass of the ball

r = 0.70 m is the radius of the circle

v is the speed of the ball

Since the ball takes t = 0.60 s to complete one full circle, its speed is

[tex]v=\frac{2\pi r}{t}=\frac{2\pi (0.70)}{0.60}=7.33 m/s[/tex]

So now we can calculate the tension in the string:

[tex]T=m\frac{v^2}{r}=(0.015)\frac{(7.33)^2}{0.70}=1.15 N\sim 1.2 N[/tex]

And we said previously, since this force acts as centripetal force, its direction is towards the centre of the circle.

Answer:

Explanation:

First you should remember that the images produced by convex mirror is virtual.

In this question, you should find the focal length using the radius of curvature, then apply the focal length relationship to find the image distance which is a virtual distance and finally use the magnification relationship to find the image height.

Let;

Find the focal length

f=focal length is half the radius of curvature

f=r/2=34/2 =17cm =0.17m (This distance is virtual thus include a -ve sign)

f= -0.17m

Apply the focal length relationship

[tex]\frac{1}{o} +\frac{1}{i} =\frac{1}{f} \\\\\\\frac{1}{0.5} +\frac{1}{i} =-\frac{1}{0.17} \\\\\\2+\frac{1}{i} =-5.88\\\\\\\frac{1}{i} =-5.88-2\\\\[/tex]

Solve for the reciprocal

[tex]\frac{1}{i} =-7.88\\\\i=-0.13m[/tex]

This is a virtual distance for the virtual image formed

Apply the magnification relationship

Magnification = height of image÷height of object

or

Magnification= - image distance÷object distance

[tex]\frac{h'}{0.20} =-\frac{-0.13}{0.5} \\\\\\0.5h'=0.13*0.20\\\\\\h'=\frac{0.13*0.20}{0.5} =0.052m=5.2cm[/tex]

The image formed by the convex mirror will be located at -50.0 cm and will have a height five times larger than the object.

To find the location and height of the image formed by a convex mirror, we can use the mirror equation / + /ᵢ = /, where is the image distance, is the object distance, and is the focal length of the mirror. Plugging in the given values, we have / + /ᵢ = /. The focal length of a convex mirror is negative, so we have / + /ᵢ = −/.

Using the given values of ᵢ = −50.0 cm and = −34.0 cm, we can solve for . The image will be located at ᵢ = −50.0 cm and will be virtual, as the image distance is negative. The height of the image can be determined using the magnification formula: = −ᵢ / . Plugging in the values of ᵢ = −50.0 cm and = −10.0 cm, we get = −(−50.0 cm) / (−10.0 cm) = 5.00.

Therefore, the image will be located at −50.0 cm and will have a height five times larger than the object.

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Ans:

Low

Explanation:

Activities in physics are divided into 3 levels, depending on the distance from the ground (or the gravitational pull on the object)

Low level (Low Plane) activities, as the name suggests, are performed at a lesser distance from the ground. Since the given statement mentions that the activity is performed closer to the ground, it will be the low level activity.

When an activity is described as being performed at a low level,

it means that it is taking place close to the ground or at a height that is not significantly above the ground.

This term is often used in contexts such as sports, exercise, or certain job tasks that require proximity to the ground.

For example, a low-level yoga pose would be one where the body is near the floor, or a low-level aerial maneuver would be performed close to the ground.

The antonym of this would be a high level, which indicates an activity performed at a considerable height above the ground.