which of these is an indication that a chemical reaction has occurred?

1) melting of a substance

2) boiling of a substance

3) formation of a precipitate

4) freezing of a substance

Answer:

B. virtual

Explanation:

Answer on edge 2020

Virtual is referred to the area which is marked as X and is denoted as option B.

This is defined as an upright image which is formed where the rays seem to diverge.

Both concave and convex lenses produces a virtual image which was why it was chosen as the most appropriate choice.

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Answer:

3, 4

Explanation:

High energy gamma rays are directed at a tumor from outside the body & gamma rays kill cancer cells in a tumor on edge.

Gamma rays are used in cancer treatment to kill cancer cells by damaging their DNA.

The use of gamma rays in cancer treatment involves the application of high-energy gamma rays to kill cancer cells. Gamma rays have characteristics similar to X-rays and are more penetrating and damaging to living tissue. In radiation therapy, high-energy radiation is used to damage the DNA of cancer cells, preventing them from dividing or killing them. This therapy can be delivered externally using a machine outside the body or internally using a radioactive substance. However, gamma rays are not absorbed only by cancer cells and can also damage healthy cells.

Answer:

The gravitational force does change believe it or not, but the explaination for this is because the earths orbit is an oval (or a not circle) the closer it nears its self to the sun. the suns gravitational pull, pulls the earth to it bringing it closer and as it reaches the other side lets call this L when it reaches L it becomes the same gravitational pull reset as P is and another section over the sun lets call this M and when it reaches M its the same pull as Q, you get it now?

The change in the magnitude of gravitational force would show that the force is more at Q than at position P

Gravitational force or force of gravity is the force of attraction between masses in the universe.

This is given by Newtons law of gravitation as;

Force (F) is directly proportional to the product of the masses and inversely proportion to the square of the distance apart.

Since the earth's orbit is oval the distance from the center is not equal at all parts of the orbit hence points closer to the earth has more force of attraction and if it is further apart it will have lesser force of attraction in conformity to  the inverse relationship.

From the picture, point P is further apart and will have lesser gravitational force while position Q is closer to the earth amd will hae more force of attraction.

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Answer:

Although graphite and diamond are both composed of carbon atoms, their physical properties are very different. The differences are the result of the atomic structures of the minerals. In graphite the carbon atoms are arranged in layers. As a result, graphite is soft. The great hardness of diamond is the result of the bonds that hold carbon atoms in a network structure.

Explanation:

for first question

there are four engines .. each producing 250,000 N so total comes 4*250,000 N

is has weight 400,000 kg

thus Calculate it 4*250,000/400,000 gives you the answer

2nd question

after calculating acceleration from first part

apply it to the third equation of kinematics

v^2 = u^2 + 2asS.

where s is the distance required

Answer:

9090 m, 104 s

Explanation:

After the acceleration phase, the rocket reaches a height of:

x = x₀ + v₀ t + ½ at²

x = (0 m) + (0 m/s) (30 s) + ½ (10 m/s²) (30 s)²

x = 4500 m

And it reaches a velocity of:

v = at + v₀

v = (10 m/s²) (30 s) + (0 m/s)

v = 300 m/s

After the fuel runs out, the rocket goes into free fall.  The maximum height reached is:

v² = v₀² + 2a(x - x₀)

(0 m/s)² = (300 m/s)² + 2(-9.8 m/s²)(x - 4500 m)

x ≈ 9090 m

The time to reach maximum height during free fall:

v = at + v₀

0 m/s = (-9.8 m/s²) t + (300 m/s)

t ≈ 30.6 s

And the time to land from the maximum height:

x = x₀ + v₀ t + ½ at²

0 m = (9090 m) + (0 m/s) t + ½ (-9.8 m/s²) t²

t ≈ 43.1 s

So the total time is:

t = 30 s + 30.6 s + 43.1 s

t ≈ 104 seconds

Using the combined gas law, we can find that the new volume of the gas would be approximately 22.62 L.

In order to find the new volume of the gas when the pressure is increased to 250 kPa and the temperature is decreased to 0°C, we can use the combined gas law.

The combined gas law states that for a given amount of gas, the ratio of pressure, volume, and temperature remains constant:

P1V1/T1 = P2V2/T2

Plugging in the values given in the question, we have:

200 kPa * 25 L / (25 + 273) K = 250 kPa * V2 / (0 + 273) K

Simplifying and solving for V2, we find:

V2 = (200 kPa * 25 L * 273 K) / (250 kPa * (25 + 273) K)

V2 ≈  22.62 L

Permanent magnet:

Hard to demagnetize

Hard

Bar magnet

Temporary magnet:

Easy to demagnetize

Soft

Thumbtack

Answer:

Permanent magnet:                    Temporary magnet:

Hard to demagnetize                  Easy to demagnetize

Hard                                             Soft

Bar magnet                                  Thumbtack

Answer:

Lowest

Explanation:

Law of superposition

The correct answer is A) lowermost.

The principle of superposition states that in an undisturbed sequence of sedimentary rocks, each layer is younger than the one below it and older than the one above it.

This means that the oldest fossils would be found in the lowermost layer of sedimentary rock, as it was deposited first. Over time, newer layers of sediment accumulate on top, preserving the older layers and the fossils they contain.

Therefore, the oldest fossils would be located in the oldest layer, which is the lowermost one. Options B, C, and D would contain progressively younger fossils, with the uppermost layer containing the youngest fossils.

The stratosphere (option C) is not a layer of rock but rather a layer of Earth's atmosphere, making it an incorrect choice for finding fossils."

Answer: Absorbs and Increases

Explanation: As temperature of this substance rises from 20°C to 50°C, the substance absorbs heat and its kinetic energy increases.

Hopefully this help you. Have a great day. :)

Answer:

Absorbs, increases.

Explanation:

As we know that the amount of heat absorb or radiate is defined by a parameter called temperature. The change in temperature is defined as the heat absorb or radiate.

In the given situation, the temperature is increased from 20°C to 50°C, this is caused due to the substance's absorption of heat.

And the temperature is defined as the measurement of average kinetic energy of all the particles which are present in object. If any body or object temperature is increasing from 20°C to 50°C than its average velocity or movement of particle becomes fast. This will lead in increase of kinetic energy.

Answer:

Its from a reflection of sound waves against a hard surface

Explanation:

If you have fifty 15-ohm resistors all connected in parallel, their "effective" resistance is (15/50) = 0.3 ohms.

Current = (voltage) / (resistance)

Current = (115 V) / (0.3 ohm)

Current = 383.3 Amperes

This is an interesting question, with a VERRRRY interesting answer.  The fuse or circuit breaker that feeds the outlet where these lights are plugged in is most likely rated 15 or 20 or 25 Amperes, and it trips immediately.

But let's say it doesn't ... let's say the juice just keeps on flowing.

Power = (voltage) x (current)

These lights use energy at the rate of (115V)x(383.3A) = 44,083 watts.  This is roughly the same as the power used to run 22 toasters or 37 blow-dryers, all at the same time.  AND ... the lights are going to produce almost as much heat as 22 toasters or 37 blow-dryers all running at the same time.  The lights will probably burn the house down before long.

If electrical energy costs 20¢ per kilowatt-hour in this city, then running those lights for ONE HOUR is going to cost $8.82 !

All in all, it will be a good idea to unplug the Christmas tree lights when the family goes to bed.

The total current in the circuit when 50 parallel-connected 15-Ohm Christmas tree lights are connected to a 115VAC source is 383.5 A.

To calculate the total current of 50 parallel connected Christmas tree lights that each have 15 ohms of resistance connected to a source of 115 VAC we will apply Ohm's law which is I = V/R. Here I represents current V represents voltage and R represents resistance.

In a parallel circuit all the resistor leads on one side of the resistors are connected together and all the leads on the other side are connected together. Therefore each resistor in a parallel circuit has the same full voltage of the source applied to it. That said, each of the 50 15-ohm lights will experience the full 115 volts.

So first we calculate the current for one light: I = V/R = 115V/15Ω = 7.67 A. Being a parallel connection each light draws this same current from the power source, so for 50 light the total current I (total) drawn will be 50 * 7.67 A = 383.5 A. Therefore, the total current in the circuit is 383.5 A.

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I would say the answer is D

A hygrometer is an instrument used to measure relative humidity. ... To determine the relative humidity, the temperatures are taken from the dry-bulb thermometer and the temperature difference between the wet and dry bulb thermometers.

hygrometer is a weather instrument used to measure the amount of humidity in the atmosphere. There are two main types of hygrometers -- a dry and wet bulb psychrometer and a mechanical hygrometer.

The correct answer is D) relative humidity, and a sling psychrometer measures this by comparing the temperatures obtained from a wet and a dry thermometer.

A device that uses the wet/dry bulb method to measure the relative humidity is the sling psychrometer. This device consists of two thermometers, with one being the dry bulb and the other being the wet bulb. The difference in temperature readings between these two allows individuals to determine the relative humidity using a psychrometric chart, which requires a knowledge of the temperature at which air becomes saturated with water vapor (dew point) as well as other related properties of moist air.

The wet-bulb temperature is particularly important in industries such as textile, wood, and chemical processing, where humidity control is crucial. With the use of a psychrometric chart, these measurements enable precise control over the environmental conditions in plant production facilities and other industrial processes.

The spectrum of infrared rays are used for the weather technology by observing the difference of temperature over specified area.

Answer : Option D

Explanation:

The infrared imagery or rather say infrared imaging is the spectral study of the infrared spectrum which is obtained by the sensors which read the certain parameters.

Here in weather technology, those sensors which are used to detect the signal or observations are scanning radiometers. The observation detected are the height of the cloud and their types. These infer in the calculation of temperature of surface water and the land.

Answer: 40 m/s^2

Explanation:

Answer:

10m/s

Explanation:

'A' is the false one, but 'C' is also so poorly worded that it's misleading.

A) 350 J

- The initial internal energy of the cup is

[tex]U_i = 230 J[/tex]

- The final internal energy of the cup is

[tex]U_f = 580 J[/tex]

According to the first law of thermodynamics:

[tex]U_f - U_i = Q+W[/tex]

where

Q is the heat absorbed by the system

W is the work done on the system

The work done on the system in this case is 0, so we can rewrite the equation as

[tex]U_f - U_i = Q[/tex]

And so we find the heat transferred

[tex]Q=580 J - 230 J=350 J[/tex]

B) IN the cup

Explanation:

in this situation, we see that the internal energy of the cup increases. The internal energy of an object/substance is proportional to its temperature, so it is a measure of the average kinetic energy of the molecules of the object/substance. Therefore, in this case, the temperature (and the energy of the molecules of the substance) has increased: this means that heat has been transferred INTO the system from the environment (the heat came from the sun).

Answer:

110

Explanation:

The net charge of the compound is the sum of the net charges due to the electrons and the protons:

[tex]Q=N_p q_p + N_e q_e[/tex]

where

Np is the number of protons

Ne = 50 is the number of electrons

[tex]N_p = +1.6\cdot 10^{-19} C[/tex] is the charge of each proton

[tex]N_e = -1.6\cdot 10^{-19} C[/tex] is the charge of each electron

[tex]Q=+9.6\cdot 10^{-18} C[/tex] is the net charge of the compound

Solving the equation for Np, we find the number of protons:

[tex]N_p = \frac{Q-N_e q_e}{q_p}=\frac{+9.6\cdot 10^{-18}C-(50)(-1.6\cdot 10^{-19}C)}{+1.6\cdot 10^{-19} C}=110[/tex]

Are there supposed to be multiple choices for this question?

Answer: water some food ALOT of FUNNN!!! and you'll live you also need the big guy up there

^

45 kg * 9.8 m/s^2 = 441 N.

Answer:

The force of a mass's weight is defined as its mass * acceleration due to gravity.

On Earth, g is about 9.8 m/s^2. This will be the acceleration due to gravity.

Then, 45 kg * 9.8 m/s^2 = 441 N.

2A, is right answer i think

Answer:

B

Explanation:

This option is exactly the same as the example. Thus it would require the same amount of heat.

Answer:

B) A 3-kg mass experiences a temperature rise of 50°C.

Explanation:

As we know that the rise in temperature for 3 kg object is 50 degree C then the heat added is given as 1000 J

so here we can say that formula of heat is

[tex]Q = ms\Delta T[/tex]

here we will have

[tex]m = mass[/tex]

s = specific heat capacity

[tex]\Delta T [/tex] = temperature rise

so here if we make all three parameters same to make this heat energy same

so correct answer will be

B) A 3-kg mass experiences a temperature rise of 50°C.

The density of the cube is 0.466 g/cm³.

The density of a cube can be calculated by dividing its mass by its volume. The volume of a cube is calculated by cubing the edge length. In this case, the mass of the cube is 65.8 g and the length of one side is 5.22 cm. To find the volume, we cube the length: 5.22 cm * 5.22 cm * 5.22 cm = 141.158088 cm³. Then, we divide the mass by the volume: 65.8 g / 141.158088 cm³ = 0.466 g/cm³.

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Answer:

Step 1 - 4. Nebular cloud of gas and dust.

Step 2. - 2. Cloud collapses under the force of its own gravitational attraction; usually triggered by a supernova.

Step 3. - 6. Condensed material begins to combine and form a core center, as it warms, a  protostar is formed.

Step 4. - 3. Other gas and matter of the nebular cloud begin to rotate around the protostar, forming a flattened disk.

Step 5. - 5. Stellar core heats as it grows; nuclear fusion begins and a star is born.

Step 6. - 1. Nuclear energy runs out; death: possible supernova.

Answer:

A star is a plasma ball held together by its gravity and compressed by a nuclear fusion at some stage in its development. The closest star on Earth is called the Sun. Several other stars can be seen in the night sky, but none of them is comparable to the Sun due to their very large distances to Earth. Traditionally, stars have been grouped into different constellations.

The stars are formed mainly by the collapse of gas vapors consisting of hydrogen due to gravity. Once the star core is formed, it slowly begins to convert hydrogen to helium in the nuclear fusion. The energy generated in the process flows from the center of the star to its surface and later radiates to outer space. The star is in equilibrium because its internal radiation pressure prevents gravity from collapsing further. When a star's hydrogen fuel is exhausted, its final fate depends on its mass: the smallest stars slowly fade away, while the more massive ones expand into red giants. Eventually, the red giants explode as a supernova, spreading various elements into space. Depending on the mass of the exploded star, for example, the remnant of an explosion may remain a neutron star or a black hole.  

By observing the motion, luminosity, and spectra of a star, it is possible to determine its other properties such as mass, age, and metal content. There are several different types of stars. The most common tool for classifying them is the Hertzsprung-Russell diagram.

Gravitationally bound star systems of two or more stars are quite common. On a large scale, stars are an important part of galaxy structure, together with interstellar gas and dark matter.

Answer:

We know there's two forces acting on a book while it sits on a table:the force of gravity pulling it down, and the normal force of the table acting upward on the book.

Explanation:

Answer:

When the object is at rest, it stays in a balanced condition and so it does not tend to move from its current position unless an external force tend to act on it.  When the external force acts on it, there will be a displacement experienced by the object.

When a book is placed on a table, it does not move it is at rest and balanced position. So If you pick up a book from the floor and place it on the table. The potential energy of the book on the desk corresponds to the work required to move the book from the floor to the desk.

Answer: it depends potential energy is the build up of kinetic energy like going to the top of a roller coaster. kintic is the use of the potential energy like going down the roller coaster so depends how much energy one another give :)

Hope this helps you out :)

Answer:

Explanation:

The question has no set meaning. Suppose you take a rock to the top of a building. You put the rock over the edge of the building. You don't drop it yet. The potential energy is greatest for the rock under this condition. The kinetic energy is 0 because the rock is not moving.

Now you let the rock go. As it falls, it looses distance to the ground which means that the Potential energy is nearing 0. The Kinetic energy is picking up because the rock is moving faster.

At the bottom of the rock's journey just before it hits the ground, the KE is at a maximum and the PE is nearly 0.

Yes! The Planet Jupiter is Magnetic

Answer: yes

Explanation:

It is surrounded by a giant magnetic field called the megnetophere

Answer:

1.28 m, 14 m/s

Explanation:

At the maximum height, the velocity is 0.

Given:

a = -9.8 m/s²

v₀ = 5.00 m/s

v = 0 m/s

x₀ = 0 m

Find:

x

v² = v₀² + 2a(x - x₀)

(0 m/s)² = (5.00 m/s)² + 2(-9.8 m/s²) (x - 0 m)

x = 1.28 m

The maximum speed is at the bottom of the well.

Given:

a = -9.8 m/s²

v₀ = 5.00 m/s

x₀ = 0 m

x = -8.5 m

Find:

v

v² = v₀² + 2a(x - x₀)

v² = (5.00 m/s)² + 2(-9.8 m/s²) (-8.5 m - 0 m)

v = -13.8 m/s

Rounded to 2 sig-figs, the maximum speed is 14 m/s.

Answer:

Explanation:

Velocity:

Formula : displacement/time

SI unit : m/s

Acceleration :

Formula: change in Velocity/time

SI unit : m/s²

Force:

Formula: mass x acceleration due to gravity

SI unit: N(newton)

Mass:

SI unit: kilogram(kg)

Answer:

1. The SI units for measuring the velocity of the car: meters per second

2.The SI units for measuring the acceleration of the car:meters per secend squared

3.The SI units of measuring force:Newton’s

4.The SI units for measuring mass:kilograms

These are the correct answers on Ed