what is the main type of heat transfer in liquids and gases?
A. Insulation
B. Convection
C. Thermal Radiation
D. Thermal Conduction
Answer: B convection
Explanation: cause :)
Final answer:
The primary heat transfer mechanism in liquids and gases is convection, which involves the movement of the fluid itself to transport heat. Conduction and radiation are the other two methods of heat transfer, with conduction involving direct contact and radiation involving electromagnetic waves.
Explanation:
The main type of heat transfer in liquids and gases is convection. Convection is the heat transfer by the macroscopic movement of a fluid, such as water or air. This process involves the circulation or movement of the fluid itself, which carries heat from one place to another. An example of convection in action is the way warm air rises and cool air falls, setting up a cycle that distributes heat throughout a room.
Heat transfer can also occur through conduction when heat is transferred through direct contact between materials, and radiation, which is the transfer of energy by electromagnetic waves and does not require a medium. These are the three fundamental methods of heat transfer: convection, conduction, and radiation.
For numbers 2 and 3, which one is compression and which one is rarefaction?
A graph that shows that the pressure of a gas varies inversely with its volume under constant temperature demonstrates
A. The pressure law
B. The density law
C. Charle’s law
D. Boyle’s law
According to the disk instability model, chunks of ______ and ______ compacted together early in the life of the solar system. rock and ice gas and du
that's wrong its actually gas and dust
Which is a property of every mixture?
(A) One substance dissolves in another substance.
(B) The molecules of one substance break down in the other.
(C) Different samples of a single mixture have different characteristics.
(D) One substance can be separated from another through physical means.
Answer:
Option D is right
Explanation:
Mixture is defined as a combination of different things in which the component elements are individually distinct.
i.e. only physically they are mixed and each substance retains its original characteristic even after mixing. For mixing, no heating or any other mode is required.
Hence out of the 4 option I option is not right since dissolution makes losing characteristic
B) is wrong since molecules cannot break down in physical mixing
C) is wrong as single mixture will have same characteristic
D) Is right One substance can be separated from another through physical means
Answer: D) One substance can be separated from another through physical means.
Explanation:
Have a wonderfullllll day:)
state the law of refraction
Answer:
The law of refraction states that the incident ray, the refracted ray, and the normal to the interface, all lie in the same plane.
Explanation:
Answer:
1 ) angle of incidence is always equal to the angle of reflection
2) the incidence ray , the normal at the point of incidence and the reflection ray , all lie in the same plane
A boy flies a kite with the string at a 30 degree angle to the horizontal. The tension in the string is 4.5N .
How much work in J does the string do on the boy if the boy stands still?
How much work does the string do on the boy if the boy walks a horizontal distance of 11m away from the kite?
How much work does the string do on the boy if the boy walks a horizontal distance of 11m toward the kite
From our physics class, we know that Work is a product of Force and Displacement. The force must be the force in the same direction with the displacement. So force and displacement must be parallel.
A. How much work in J does the string do on the boy if the boy stands still?
Since we know that: Work = Force * Displacement
and in this case displacement is equal to zero, therefore Work must also be equal to zero.
Work = 0
B. How much work does the string do on the boy if the boy walks a horizontal distance of 11m away from the kite?
Now are given a displacement of 11 m which is a horizontal distance. Therefore we must first calculate the horizontal component of force:
Fx = 4.5 N * cos 30
Fx = 3.897 N
So work is:
Work = 3.897 N * 11 m
Work = 42.87 J ~ 43 J
The string does 49.5J of work on the boy when he stands still, -49.5J when he walks away from the kite, and 49.5J when he walks toward the kite.
Explanation:The work done by the tension in the string on the boy can be calculated using the formula:
Work = Force * Distance * cos(θ)
where θ is the angle between the force vector and the displacement vector. In this case, the tension force is acting horizontally, so the angle between the force and displacement vectors is 0 degrees.
Therefore, for the first scenario (boy standing still), the work done by the string is:Work = 4.5N * 11m * cos(0°)
Since cos(0°) = 1, the work done by the string is:Work = 4.5N * 11m * 1 = 49.5J
In the second scenario (boy walking away from the kite), the displacement vector is in the opposite direction of the tension force, so the angle between them is 180 degrees.
Therefore, the work done by the string is:Work = 4.5N * 11m * cos(180°)
Since cos(180°) = -1, the work done by the string is:Work = 4.5N * 11m * -1 = -49.5J
In the third scenario (boy walking toward the kite), the displacement vector is aligned with the tension force, so the angle between them is 0 degrees.
Therefore, the work done by the string is:Work = 4.5N * 11m * cos(0°)
Since cos(0°) = 1, the work done by the string is:Work = 4.5N * 11m * 1 = 49.5J
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Read the paragraph.
Long ago people made buildings by fitting boards together. Then they learned to shape metals. The invention of nails followed.
Which word does the underlined prepositional phrase modify?
A. the verb made
B. the noun people
C. the verb learned
D. the noun buildings
Can Some One Help Me Please its Language Arts
Answer:a
Explanation:
took quiz
This force on compass dials is an example of a force that _______.
A. needs electricity to act.
B. acts through particles in the air
C. acts only on contact.
D. acts at a distance.
acts at a distance
is the answer
If you have a mineral sample with a volume of 4 ml and a mass of 20 grams , what is the density ?
The density of a mineral sample with a volume of 4 ml and a mass of 20 grams is 5 grams per milliliter (g/ml).
If you have a mineral sample with a volume of 4 ml and a mass of 20 grams, the density can be calculated using the formula:
Density = Mass / Volume
Substituting the given values into the formula, we get:
Density = 20 grams / 4 ml = 5 grams per milliliter (g/ml).
PLEASE HELP!!!!!!!!!!!
Will it float? YES or NO
Ice = 0.92g/cm3
Wood = 0.45 g/cm3
Tim observes that a force pulls him down when he jumps up in the air. Based on his observation, which conclusion is correct?
Gravitational force is a contact force.
Gravitational force helps objects float.
Gravitational force pushes an object up.
Gravitational force is a non-contact force.
Answer:
Gravitational force is a non-contact force.
Explanation:
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3) The atomic number of magnesium is 12. This means that its nucleus must contain
A) 6 protons and 6 neutrons.
B) 6 neutrons and 6 electrons.
\C) 12 neutrons and no protons.
D) 12 protons and no electrons.
The answer is D. 12 protons and no electrons.
The nucleus is the center of an atom that contains protons and neutrons. Electrons are located AROUND the nucleus in energy levels, not in the nucleus.
Why do we have seasons? Give 3 reasons.
Which type of rock can form if extreme heat and pressure are applied to sedimentary rock?
A) granite
B) igneous rock
C) metamorphic rock
D) sedimentary rock
Answer:
c
Explanation:
What is meant by saying that a wave has a low frequency?
A. The wave is very tall
B. The wave is very long
C. Few wave peaks pass a point in one second
D. A large number of wave peaks pass a point in one second.
If the kinetic and potential energy in a system are equal, then the potential energy increases. What happens as a result?
An increase in potential energy in a system where kinetic energy remains constant leads to an overall increase in the system's internal energy. This conservation of mechanical energy illustrates the exchange between potential and kinetic energy without an overall energy increase, provided there are no energy losses such as friction.
When the potential energy in a system is said to increase while the kinetic energy remains equal to the original potential energy, the total internal energy of the system increases. If there is a net transfer of energy into the system and the macroscopic mechanical energy—like overall speed and elevation—does not change, then this increase in energy is attributed to a rise in the system's internal potential energy or internal kinetic energy, or a combination of both.
Gravitational potential energy increases as an object is moved higher from the surface of the Earth, as the force of gravity does negative work. This potential energy is then available to be converted back into kinetic energy, as seen when an object falls back towards the Earth, picking up speed and thus kinetic energy, as it descends.
In cases where the system is not isolated, an input of energy can lead to an increase in the system's mass, according to the principle that mass and energy are equivalent. Moreover, in the absence of external forces like friction, the mechanical energy of the system remains constant, with a conversion between kinetic and potential energy, but not an overall increase.
When the potential energy in a system increases to be equal to the kinetic energy, this indicates a transfer of energy within the system where the internal potential energy is rising. This increase in potential energy is often associated with the separation of particles, leading to an eventual rise in energy.
The increase in internal energy can result in a rise in temperature, or it can manifest as an increase in the potential energy of the system. Mathematically, the potential energy rises as particles move farther apart until it reaches a maximum value of zero.
a naturally occurring element has a melting point of 240°C and a boiling point of 300°C. A.identify the elements state of matter at 0°C and explain why the element is in this state
The boiling point and melting point of the given element is relatively higher and thus it exhibits strong intermolecular forces. Hence, the element at 0°C is in solid state.
What is melting point?Melting point of a substance is the temperature at which it changes from solid state to liquid state. Boiling point of the substances is the temperature at which it converts from liquid state to vapor state.
Both melting point and boiling points are physical quantities depends on the bond type, molecular weight, temperature and pressure. Strong the bond means more energy needs to weaken the bond and to melt or boil.
The make the molecules apart from each other to change them from the solid state to liquid or gaseous state, higher temperature have to be applied .
Hence a boiling point of 300°C and melting of 240°C indicates that they have strong intermolecular force in solid state and thus are in solid state at lower temperature as in 0°C.
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In the chemical formula for an ionic compound which item is written first
Final answer:
In the chemical formula for an ionic compound, the metal is written first followed by the nonmetal.
Explanation:
In the chemical formula for an ionic compound, the metal is written first followed by the nonmetal.
For example, in the ionic compound sodium chloride (NaCl), sodium is the metal and is written first, followed by chlorine which is the nonmetal.
It is important to note that the formula for an ionic compound shows how many of each ion is needed to balance the total positive and negative charges, and the name does not need to include indication of this ratio.
What is the unit for IMA?
It's unitless.
20 characters
Which of these is an example of a physical change? Question options: wood decaying iron melting paper burning steel rusting
Final answer:
Iron melting is an example of a physical change because it involves a state change without altering the substance's chemical composition.
Explanation:
An example of a physical change from the options provided is iron melting. Physical changes are characterized by a change in the state or properties of matter without altering its chemical composition. When iron melts, it changes from solid to liquid, but the substance remains iron; its molecules are not changed. Other examples of physical changes might include boiling water, dissolving sugar in water, or breaking a mirror. Conversely, wood decaying, paper burning, and steel rusting involve chemical reactions that create new substances, thus, they are chemical changes.
A 3.0-kg block sits on top of a 5.0-kg block which is on a horizontal surface. The 5.0-kg block is pulled to the right with a force F⃗ as shown in the figure. The coefficient of static friction between all surfaces is 0.57 and the kinetic coefficient is 0.43. What is the minimum value of F needed to move the two blocks?
Final answer:
The minimum value of the force needed to move the two blocks is approximately 27.93 N.
Explanation:
To determine the minimum value of the force needed to move the two blocks, we need to consider the friction between the blocks and the surface. Since the coefficient of static friction is given, we can use it to find the maximum static friction force:
Fstatic_max = μstatic × N
where μstatic is the coefficient of static friction and N is the normal force. Since the 3.0-kg block is sitting on top of the 5.0-kg block, the normal force on the 5.0-kg block is equal to its weight:
N = m × g
where m is the mass of the 5.0-kg block and g is the acceleration due to gravity. Once the force F is greater than the maximum static friction force, the blocks will begin to move. The minimum value of F needed to move the two blocks is therefore equal to the maximum static friction force:
F = Fstatic_max
Substituting the given values, the equation becomes:
F = μstatic × (m × g)
Plugging in the values, we get:
F = 0.57 × (5.0 kg × 9.8 m/s²)
Simplifying, we find that the minimum value of F needed to move the two blocks is approximately 27.93 N.
I’m a soulution of a carbonated beverage the water is the _____
A. Solute
B. Solvent
C. Saturated
D. Precipitate
What is the best explanation of Moon phases?
If a helicopter's mass is 4,500kg and the net force on it is 18,000 N upward, what is its acceleration?
Answer:
Acceleration, [tex]a=4\ m/s^2[/tex]
Explanation:
It is given that,
Mass of the helicopter, m = 4500 kg
Net force acting on the helicopter, F = 18000 N
Let a is the acceleration of the helicopter. The force acting on an object is equal to the product of mass and acceleration. It is calculated as :
[tex]F=ma[/tex]
[tex]a=\dfrac{F}{m}[/tex]
[tex]a=\dfrac{18000\ N}{4500\ kg}[/tex]
[tex]a=4\ m/s^2[/tex]
So, the acceleration of the helicopter is [tex]4\ m/s^2[/tex]. Hence, this is the required solution.
The acceleration of the helicopter with a mass of 4,500kg and the net force of 18,000N is 4m/s².
HOW TO CALCULATE ACCELERATION:
The acceleration of a moving body can be calculated by dividing the force applied by the mass. That is;Acceleration (m/s²) = Force (N) ÷ mass (kg)According to this question, a car has a mass of 4500 kg and a force of 18000 N. The acceleration can be calculated as follows:Acceleration = 18000 ÷ 4500Acceleration = 4m/s²Therefore, the acceleration of the helicopter with a mass of 4,500kg and the net force of 18,000N is 4m/s².Learn more at: https://brainly.com/question/17289046?referrer=searchResults
What happens to the particles of the liquid inside a thermometer when the thermometer is heated?
They slow down and spread apart.
They speed up and spread apart.
They slow down and move closer together.
They speed up and move closer together.
Speed up and spread apart
what is the difference between magnetism and a magnetic field
Magnetism is a force that can attract "pull toward" or repel "push away" some materials. Certain elements such as cobalt, iron, and nickel. are strongly attracted by a magnetic force and are called ferromagnetic.
A magnetic field is the area of space around a magnet where magnetism is detected. The poles are where the magnetic field is the strongest. The larger the magnet, the greater its magnetic field is.
For which question could a testable hypothesis be developed
Testable hypotheses can be developed for questions related to the effect of temperature on the duration of blood storage and the impact of moisture on moss growth. For example, one hypothesis could be that blood can be stored for a longer duration at lower temperatures. Similarly, another hypothesis could be that increased moisture levels will lead to faster growth of moss on a tree. These hypotheses can be tested through controlled experiments to investigate the relationships between the variables involved.
A testable hypothesis can be developed for the following questions:
1. Do children’s heart rates increase at the same speed when walking uphill?
Hypothesis: "Children's heart rates will increase at a slower speed when walking uphill compared to walking on a flat surface."
3. Does temperature affect how long blood can be stored?
Hypothesis: "Blood can be stored for a longer duration at lower temperatures compared to higher temperatures."
4. How does moisture affect the growth of moss on a tree?
Hypothesis: "Increased moisture levels will lead to faster growth of moss on a tree."
These questions involve variables that can be controlled and manipulated in an experiment to test specific hypotheses.
Complete Correct Question:
For which of these questions could a testable hypothesis be developed? Check all that apply.
Do children’s heart rates increase at the same speed when walking uphill?
Is experimenting with moldy bread more fun than experimenting with yogurt cultures?
Does temperature affect how long blood can be stored?
How does moisture affect the growth of moss on a tree?
Which of Leeuwenhoek’s microscopes was the coolest?
Why are the four inner planets in our solar system dense and rocky while the outer planets are gaseous?
A) In the young universe hydrogen and helium where the only elements.
B) Intense radiation from our Sun blasted much of the hydrogen and helium into the outer reaches of our Solar System, while heavier elements remained closer.
C) Planets form from particles in a disk of gas and dust, colliding and sticking together as they orbit the star.
D) A small contending planet, about one-tenth the size of Earth, must have collided with Earth about 4.45 billion years ago.
The four inner planets in our solar system dense and rocky while the outer planets are gaseous because planets form from particles in a disk of gas and dust, colliding and sticking together as they orbit the star.
What is solar system?The solar system consists of the Sun and everything that orbits, or travels around, the Sun. This includes the eight planets and their moons, dwarf planets, and countless asteroids, comets, and other small, icy objects.
The inner planets are made of rocky material, which has higher density; these are often known as terrestrial planets. The outer planets are made mostly of low density gases; these are often known as Jovian planets.
And also the four inner planets have shorter orbits, slower spin, no rings, and they are made of rock and metal. The four outer planets have longer orbits and spins, a composition of gases and liquids, numerous moons, and rings.
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Which of the following is an element?
A. Water
B. Carbon Dioxide
C. Oxygen
D. Ammonia
Oxygen (C) is the element among the given options. It is a pure substance found on the periodic table as 'O', while the other choices are compounds consisting of various elements combined.
The question which of the following is an element? A. Water B. Carbon Dioxide C. Oxygen D. Ammonia - requires identifying the pure element from a list that includes compounds. An element is a substance that consists of only one type of atom, whereas a compound is a substance made from more than one type of atom joined by chemical bonds.
Out of the given options, Oxygen (C) is the correct answer. Oxygen is an element that is listed on the periodic table as 'O'. It is also one of the seven diatomic molecular elements, meaning it's commonly found as two atoms of oxygen bonded together (O₂). In contrast, water (H₂O), carbon dioxide (CO₂), and ammonia (NH₃) are compounds made up of hydrogen, carbon, and nitrogen atoms joined with oxygen in different combinations.