Which of the following substance used to selectively absorb certain frequencies of light and transmit or reflect the rest; responsible for object's colour?
A. Reflection
B. Refraction
C. Pigment
D. Tyndall scattering​

Answer:

umm.....the teachers and friends

The drama, and friends.

Answer:

the answer is false

Explanation:

A wave travels at a constant velocity through a given material.

Answer:

F= 1800N

Explanation:

the equation for force is F= ma

so plug in the numbers: F= (120)(15)

solve this to get F= 1800N

tip: don't forget to add the units when writing your answer :)

Answer:

The correct choice is D. Its gravitational potential energy must increase

Explanation:

Conservation of Mechanical Energy

The total amount of mechanical energy, in a closed system in the absence of dissipative forces like friction or air resistance, remains constant.

This means that energy cannot disappear or appear and that potential energy can become kinetic energy or vice versa.

In a closed system like a pendulum, two types of energies are considered: Gravitational potential (U) and kinetic (K). Thus, the sum of both energies must remain constant in time.

Suppose the pendulum is at a state where U=150 J, and K=350 J. The total mechanical energy is:

M = 150 J + 350 J = 500 J

If the kinetic energy decreases to a new value, say K = 200 J, then the gravitational potential must increase to compensate for this new condition, that is: U = 300 J

The correct choice is D. Its gravitational potential energy must increase

Taking into account the definition of kinetic, potencial and mechanical energy, the correct answer is option D:  If  the pendulum's kinetic energy decreases Its gravitational potential energy must increase.

Kinetic energy is a form of energy. It is defined as the energy associated with bodies that are in motion and this energy depends on the mass and speed of the body.

Kinetic energy is defined as the amount of work necessary to accelerate a body of a given mass and at rest, until it reaches a given speed. Once this point is reached, the amount of accumulated kinetic energy will remain the same unless there is a change in speed or the body returns to its state of rest by applying a force.

On the other hand, potential energy is the energy that measures the ability of a system to perform work based on its position. In other words, this is the energy that a body has at a certain height above the ground.

Gravitational potential energy is the energy associated with the gravitational force. This will depend on the relative height of an object to some reference point, the mass, and the force of gravity.

Finally, mechanical energy is that which a body or a system obtains as a result of the speed of its movement or its specific position, and which is capable of producing mechanical work. Then:

Potential energy + kinetic energy = total mechanical energy

The principle of conservation of mechanical energy indicates that the mechanical energy of a body remains constant when all the forces acting on it are conservative (a force is conservative when the work it does on a body depends only on the initial and final points and not the path taken to get from one to the other.)

Therefore, if the potential energy decreases, the kinetic energy will increase. In the same way, if the kinetics decreases, the potential energy will increase.

This principle can be applied in this case. The mechanical energy of the pendulum remains constant when all the forces acting on it are conservative.

So, the correct answer is option D:  If  the pendulum's kinetic energy decreases Its gravitational potential energy must increase.

Learn more about mechanical energy:

Answer:

V= I x R =250 x 0.0198 = 4.95 Volts

Explanation:

The voltage across the resistor is 4.95 Volts.

Given that the resistance is 0.0198 ohms and the current flowing through the silver is 250 amps.

The voltage V across the resistor is the product of the current I flowing through the resistors and resistance R.

[tex]V = IR[/tex]

Substituting the values, we get the voltage.

[tex]V = 250 \times 0.0198[/tex]

[tex]V = 4.95 \;\rm V[/tex]

Hence we can conclude that the voltage across the resistor is 4.95 Volts.

To know more about the voltage, follow the link given below.

https://brainly.com/question/238298.

Answer:

5.3m/[tex]s^{2}[/tex]; 7.45m/[tex]s^{2}[/tex]

Explanation:

the magnitude of a=(change in speed)/(the time took to accelerate to the speed above)

So for that sports car, a=(26.8m/s-0m/s)/(5.1s)=5.2549m/[tex]s^{2}[/tex], knowing from the question that the sig fig of this question depend on "5.1 seconds", so the answer should be 5.3 m/[tex]s^{2}[/tex]

For the rocket, a=(447m/s-0m/s)/(1 minute)=(447m/s)/(60s)=7.45m/[tex]s^{2}[/tex]

Answer:

c. Water

Explanation:

The solvent is the substance in which a solute is dissolved to make the solution.

In this case, the water is the solvent, the flavored powder is the solute, and the solution is the final drink.

Answer:

B. The velocity of an object

c. The mass of an object

Explanation:

Answer:

Unlike a fact witness, an expert is entitled to compensation for participation in the case. A key distinction between a fact witness and an expert witness is that an expert witness may provide an opinion. Fact witnesses must limit their testimony to facts in regard to evidence they may have observed or been involved.

Explanation:

there

Answer:

Unlike a fact witness, an expert is entitled to compensation for participation in the case. A key distinction between a fact witness and an expert witness is that an expert witness may provide an opinion. Fact witnesses must limit their testimony to facts in regard to evidence they may have observed or been involved.

Explanation:

E2020

Answer:

A)  distillation.

Explanation:

Benzene boils at 81∘C while chloroform at about 61∘C. The separation can be done by distillation.

please mark me brainliest! hope this helps, god bless :)

Answer:

A. Be behind the package

Answer:

MA = 4

Explanation:

In order to solve this problem, we must use the definition of the ideal mechanical advantage, which tells us that it is equal to the relationship of the inclined distance over the height with respect to the level of the ground

MA = L / h

where:

MA = mechanical advantage

L = Length of the inclined plane = 10 [m]

h = elevation = 2.5 [m]

MA = 10/2.5

MA = 4

Answer:

35 m/s

Explanation:

i know all

Answer:

amplitude of a wave is the maximum displacement of a particle from its rest position

Answer:

4 m/s

Explanation:jus did on edgu 2020

Answer:

620

Explanation:

Answer:

100

correct me if I am wrong

Answer:

the presence of impurities on the surface of a substance directly affects the surface tension of a liquid

Explanation:

the surface tension of water will increase when highly soluble impurities are added

Answer:

The two main components of an atom are the nucleus and the cloud of electrons

postive ion

Explanation:

your welcome !!

postive ion explation - When an atom that has no charge loses two electrons, it becomes a positive ion. negative ion. positive isotope. negative isotope When an atom that has no charge loses two electrons, it becomes a positive ion.

Answer:

variables on the horizontal and vertical axis (slope, outliers, +/- correlation, etc)

Explanation:

Answer:

15.34 i think

Explanation:

Answer:

Explanation:   To breakdance, ask a friend or a professional, surf the internet, or invent your own moves. You don't have to master other breakdancers' moves to be a breakdancer yourself. You breakdancing by ...

Answer:

2.5 g/cm³

Explanation:

To find density, divide the mass by the volume. In this case, 15 grams divided by 6 cm³ equals 2500 kg/m³, or simplified, 2.5 g/cm³. Hope it helps! To type ³, turn on Num Lock and then press Alt+0179. Have a good day!

Answer:

Fx  = 4.92 [N]

Fy = 0.868 [N]

Explanation:

Let's take the 10 degrees as a measure from the horizontal component to the vector.

Thus taking the components in the X & y axes respectively:

Fx = 5*cos(10) = 4.92 [N]

Fy = 5*sin(10) = 0.868 [N]

Answer:

it is  C. The kinetic energy is greater after a substance changes from a

gas to a plasma.

Explanation: The higher the temperature the higher the kinetic energy

pls vote for me

Answer:

The correct option is;

7.49 m/s

Explanation:

The time it takes the marble to fall vertically is given by the equation

s = u·t + 1/2·g·t²

Where;

s = The height of the table = 1.4 m

u = The initial vertical velocity = 0 (The marble is given only an initial horizontal push (velocity))

g = The acceleration due to gravity = 9.81 m/s²

t = The time it takes the marble to reach the ground 1.4 m below

Plugging in the values. gives;

1.4 = 0×t + 1/2 × 9.81 × t²

∴ t² = 1.4/(1/2 × 9.81) ≈ 0.28542 s²

t = √0.28542 ≈ 0.5342s

The horizontal range the marble is to cover in the approximately 1.87 seconds before it reaches the ground = 4 meters

Therefore, the velocity that allows the marble to reach 4 meters in 1.87 seconds is give as follows;

Velocity = Distance/Time = 4 m/(0.5342 s) ≈ 7.49 m/s

Therefore the horizontal velocity the marble must have to strike its target is approximately 7.49 m/s.

Answer:

ancient astronomy is back in the 1600s and is really old and modern astronomy is present and astronomy today

Time period and technology are the main differences between ancient and modern astronomy.

The main differences between ancient and modern astronomy is the era in which they were created and developed. The ancient astronomy developed by Greeks and technology for study is very old. The first documented records of systematic astronomical observations occurs in Assyro-Babylonians around 1000 BCE.

While on the other hand, modern astronomy refers to the astronomy that is developed in this modern period and use advance technology. Modern astronomy includes many elements of the motions as well as characteristics of moving bodies so we can conclude that time period and technology are the main differences between ancient and modern astronomy.

Learn more: https://brainly.com/question/18659457

Answer:Lead by an example

Practice what you preach. You'll never convince anyone to conserve water if you aren't doing it yourself.

Engage with others.

Seek out allies.

Give people a reason to save.

Provide entry-level strategies.

Encourage others to challenge themselves.

Think big.

Choose a monthly focus.