Answer:
Neither energy nor matter
Explanation:
A system is defined as the part of the universe. In thermodynamics, systems are of three types i.e.
1. Open System : In an open system, both energy and matter can freely exchange with surrounding. For example- boiling water in an open pan transfers both energy and matter.
2. Closed system : In a closed system, only energy is exchanged with the surrounding. For example- boiling water with a lid on the pan exchanges only energy with the surrounding.
3. Isolated system : In an isolated system, neither energy nor matter exchanges with the surrounding. For example : a thermos flask does not exchange energy and matter with the surrounding.
Hence, the correct option is (a) " neither energy nor matter ".
Which of these is a pure substance?
a. diamond
b. salt
c. ocean water
a
a and b
b and c
all of them
Answer:
The correct answers are A and B. Diamond and salt are pure substances.
Explanation:
A pure substance is one whose composition does not vary, even if the physical conditions in which it is found change. For example, water has a formula that is H2O and is always the same, which indicates that it is made up of molecules in which there are 2 hydrogen atoms and 1 oxygen atom. If I changed that formula, it would be another different substance.
A pure substance cannot be broken down into other simpler substances using physical methods.
A pure substance has its own or defined characteristic properties.
Which benefit of stretching makes you more comfortable when you move around?
Answer:
Stretching refers to the physical exercise in which a specific muscle or muscle group is deliberately flexed or extended.
It improves the elasticity and tonicity of the muscles.
Benefits of stretching may include:
It reduces the muscle tension It increases range of motion of the joints It enhances the muscular coordination It increases the blood circulation to various parts of the body .Blood circulation increases the energy of the muscles.You push a coin across a table. The coin stops. How does this motion relate to balanced and unbalanced forces?
calculated the gravitational potential energy of a 93.0 kg sky diver who is 550 m above the ground
Final answer:
The initial gravitational potential energy of a 93.0 kg skydiver at 550 m above the ground is 501,090 Joules.
Explanation:
The initial gravitational potential energy ([tex]PE_g[/tex]) of a 93.0 kg skydiver when they are 550 m above the ground can be calculated using the formula
[tex]PE_g[/tex] = mgh, where 'm' is mass, 'g' is the acceleration due to gravity (9.8 m/s2), and 'h' is the height above the ground. So the initial gravitational potential energy
[tex]PE_g[/tex] = (93 kg) × (9.8 m/s2) × (550 m) = 501,090 Joules (J).
Difference between angle of shear and angle of twist.
Answer:
The angle of shear can be defined as the angle of the deformation that occurs on the sides when the object is exerted upon by shearing stress or deformation force.
The angle of twist can be defined as the angle through which the rotating machine element rotates or twists with respect to its free end. The angle of twist exists because of the torque.
So i am doing a science fair project and its about earthquakes so im going to need different supports for my buildings. I found springs but now i need 3 more. URGENT!!
Answer the question below based on the periodic table entry for silicon. What is the atomic mass? 2 14 28 28.08
false lies forgive me Based on the periodic table entry for silicon, the atomic mass of silicon is 28.08.
28.08
Explanation;The atomic mass of a given element is the sum of the masses of its isotopes, each multiplied by its natural abundance. Isotopes are atoms of the same element with the same atomic number but different mass number. Atomic number on the other hand is the number of protons in the nucleus of an atom.Silicon is an element in group 4 in the periodic table, it has an atomic mass of 28.08. It has an atomic number 14, which means it has 14 protons in the nucleus of its atom, and thus it has 14 electrons in the energy levels, and therefore, its electronic configuration is; 2:8:4.Difference between Daniel and Leclanché cells
Explanation :
Daniel cells:
It is a primary cell. It consists of a zinc rod and a copper vessel (in fig 1). It can be seen that a zinc rod is put in dilute sulfuric acid which is contained in a porous pot.
Daniel cell works on the principle of the redox reaction. The electrons pass form zinc rod to wire. Then it passes to the copper rod. Thus, a current is produced.
It produces an EMF of 1 volt.
Leclanche cell :
Leclanche cell is also known as dry cells (fig 2). It contains an electrolyte of ammonium chloride. Carbon acts as a cathode while zinc is an anode.
It produces an EMF of 1.4 volts.
Answer:
Explanation:
A Leclanche cell consists of a carbon electrode packed in a porous pot containing manganese dioxide and charcoal powder (Fig 2.22). The porous pot is immersed in a saturated solution of ammonium chloride (electrolyte)
How many positions coordinates are required to identify the position of a system undergoing one dimensional motion and what symbols should you use to identify a systems position in one dimensional motion
a sprinter's whose mass is 70 kg accelerstes from rest to 11 m/s in 6 seconds what is the acceleration what force did this require
Final answer:
The acceleration of the sprinter is approximately 1.83 m/s², and the force required to accelerate the sprinter is approximately 128.1 N.
Explanation:
The acceleration of a sprinter can be calculated using the formula:
acceleration = (final velocity - initial velocity) / time
Given that the sprinter's mass is 70 kg, the final velocity is 11 m/s, and the time taken is 6 seconds, we can substitute these values into the formula:
acceleration = (11 m/s - 0 m/s) / 6 s = 11 m/s / 6 s ≈ 1.83 m/s²
The force required to accelerate the sprinter can be determined using Newton's second law of motion:
force = mass x acceleration
Substituting the mass (70 kg) and acceleration (1.83 m/s²) into the formula:
force = 70 kg x 1.83 m/s² ≈ 128.1 N
How long would it take you to hop 30 meters if you hopped 5 m/s?
To hop 30 meters at a rate of 5 meters per second, it would take 6 seconds, calculated using the formula t = d/v where t is time, d is distance, and v is velocity.
Explanation:If you hopped at a rate of 5 meters per second (m/s), to cover a distance of 30 meters, you would use the basic formula for distance, which is distance equals speed times time (d = vt). Here, you want to find the time (t), so you rearrange the formula to t = d/v.
Substituting in our known values gives us t = 30 m / 5 m/s, which simplifies to t = 6 seconds. Therefore, it would take you 6 seconds to hop 30 meters at a speed of 5 m/s.
Summarize the main ideas of Dalton’s atomic theory
Dalton's atomic theory states that matter is made up of atoms, which are indivisible. These atoms are identical within an element and different across elements. They combine in specific proportions to form compounds and in chemical reactions, they are rearranged but not created or destroyed.
Explanation:John Dalton’s atomic theory includes several primary ideas. The first is that all matter is composed of atoms, which are small, indivisible particles. Secondly, atoms of the same element are identical to each other in terms of mass and properties, while atoms of different elements are different. Thirdly, atoms combine in specific proportions to form compounds. Lastly, in chemical reactions, atoms are rearranged but they are not created, destroyed or changed into atoms of another element.
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How do microwaves cook food or heat water?
Microwaves in an oven heat food by causing water molecules to align and transfer energy to the thermal motion of the water.
Explanation:Microwaves in an oven are produced electronically by accelerating electrons. The oscillating electric field of the microwaves inside the oven exerts a torque on water molecules in food, causing them to heat up. The water molecules have a dipole moment, which means they have separated centers of equal and opposite charges. The microwaves cause the water molecules to align in one direction and then in the other, transferring energy to the thermal motion of the water and heating the food.
A (n)________ is a material that does not conduct heat well
A hooked weight is suspended by two wires. The gravitational force acting on the weight is 1.0N,downward. Is it possible for the two wires to exert forces that have magnitude of 0.60 N and 0.70 N on the hooked weight?
The tension in the wires must be equal to the weight of the hooked weight for it to be in equilibrium, so it is not possible for the two wires to exert forces with magnitudes of 0.60 N and 0.70 N on the hooked weight.
Explanation:The tension in the wires must be equal to the weight of the hooked weight for it to be in equilibrium. Since the gravitational force acting on the weight is 1.0 N downward, the sum of the magnitudes of the tensions on the two wires must also be 1.0 N to cancel out the gravitational force. Therefore, it is not possible for the two wires to exert forces with magnitudes of 0.60 N and 0.70 N on the hooked weight.
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I'm in 7th grade and I need help with 1.04 law of conservation of energy can someone please help me today
The law of conservation of energy states that the total energy in a system remains constant. Energy can be transferred from one system to another or change form, but the total amount of energy remains the same.
Explanation:The law of conservation of energy states that the total energy in a system remains constant. Energy can be transferred from one system to another or change form, but the total amount of energy remains the same. For example, when a ball is raised to a certain height, it gains potential energy. As the ball falls, the potential energy is converted to kinetic energy. The sum of the potential and kinetic energy remains constant throughout the process.
In object of mass 30 kg is in freefall in a vacuum where there is no air resistance determine the acceleration of the object
Redshift means stars and galaxies are emitting a color that is shifting toward the red end of the color spectrum. this indicates the light's wavelengths are _____ and less frequent, and the star or galaxy is____?
Answer:
Redshift means stars and galaxies are emitting a color that is shifting toward the red end of the color spectrum. this indicates the light's wavelengths are MORE and less frequent, and the star or galaxy is MOVING AWAY
Explanation:
As we know that by Doppeler's effect of light when source is moving away from the observer then the frequency observed by the observer is given as
[tex]\frac{\Delta \nu}{\nu} = \frac{v}{c}[/tex]
so here on moving away the frequency observed by observer will decrease and hence we can say that the wavelength of light must be increased
So here on increasing the observed wavelength we say it to be shifted towards higher side which means it is red shift
so here correct answer would be
Redshift means stars and galaxies are emitting a color that is shifting toward the red end of the color spectrum. this indicates the light's wavelengths are MORE and less frequent, and the star or galaxy is MOVING AWAY
an object wants to maintain its state of motion because it has mass
what is the speed of a 2.5-kilogram mass after ot has fallen freely from rest through a distance of 12 meters? a) 4.8 m/s b) 15 m/s c) 30. m/s d) 43 m/s
v₀ = initial velocity of the mass = 0 m/s (since the mass falls from rest)
a = acceleration = acceleration due to gravity = 9.8 m/s²
d = vertical distance traveled = 12 m
v = final velocity of the mass
Using the kinematics equation
v² = v₀² + 2 a d
v² = 0² + 2 (9.8) (12)
v² = 235.2
v = √235.2
v = 15 m/s
hence the speed of mass comes out to be
b) 15 m/s
If enough heat was REMOVED from B, it would change into ____________.
A.) a gas
B.) plasma
C.) a liquid
D.) a solid
Answer:
D
Explanation:
If you take heat away from a liquid it would turn into a solid, therefor being D a solid
Hope this helps :)
Your teacher gives you 30 mL of vinegar and one gram of baking soda and tells you to find evidence that the law of conservation of mass is correct. Design an experiment to find this evidence and state your expected results.
To demonstrate the law of conservation of mass with vinegar and baking soda, an experiment can be designed where total mass is measured before and after the reaction in a closed system, showcasing that mass remains unchanged as expected by this fundamental chemical law.
To demonstrate the law of conservation of mass using vinegar (acetic acid) and baking soda (sodium bicarbonate), you could design an experiment where you react these two substances and measure the total mass before and after the reaction. Here are the steps you would follow:
Place a clean, dry flask or beaker on a precise digital scale and tare the scale to zero.
Add 30 mL of vinegar to the flask and note the mass.
In a separate container, weigh out one gram of baking soda.
Quickly but carefully add the baking soda to the vinegar in the flask and immediately seal the flask with a balloon or a rubber stopper with a tube to capture any gases produced.
Allow the reaction to proceed completely. This reaction produces carbon dioxide gas, water, and sodium acetate.
Weigh the sealed flask again once the reaction has stopped.
The expected result is that the total mass of the sealed system (flask, vinegar, baking soda, products, and gas within the balloon or stopper) should remain constant as per the law of conservation of mass.
Expected Results
If the experiment is done correctly, there should be no mass change. This is because, according to the law of conservation of mass, mass is neither created nor destroyed in a chemical reaction. In a closed system, the total mass before and after the reaction should be the same, even though the substances' physical states and chemical forms may change.
Over the last several decades, scientists have addressed the problem of nonrenewable natural resources such as fossil fuels. Humans are using fossil fuels at a rapid rate and scientists believe that one day we will run out of them. To solve this problem, research has been conducted on alternative energy sources. One alternative energy source is nuclear energy. Although nuclear energy is a good solution to this problem, there are concerns.
Which of these is NOT a benefit of nuclear energy?
A) fossils fuels are not required
B) does not contribute to global warming
C) presence of hazardous radioactive materials
Eliminate
D) little carbon emissions released into the air
Answer:
Option (C)
Explanation:
The nuclear energy is defined as a type of energy which liberates either by the process of nuclear fusion or nuclear fission and is mainly used to generate electricity. This energy is stored in the core of an atom (or nucleus).
It is highly effective, cost-effective and there is no emission of greenhouse gases.
But it also has some disadvantages, of which one is that it produces radioactive waste materials, which are difficult to dispose these substances and is also a very expensive method. These materials emit radiations that are harmful to the organisms. So, it is very challenging to dispose these radioactive waste materials.
Thus, the correct answer is option (C).
Answer:
c.
Explanation:
presence of hazardous radioactive materials
Why is it expensive to bring electricity into urban areas?
There are various reasons that electricity transmission in urban areas is expensive.
What do you know about electricity supply in urban areas?The electricity to the urban area is supplied by the power plants and the power plants are set up in the rural areas if it is a hydropower plant then it will be set up near the river in the rural areas.
The various reasons for high electricity costs in urban areas are:-
Population density is the population in the urban area is large in the small areas a large number of people live. The transmission line set-up will be costly.Power plants are not located in cities. Power has to travel a long distance over power lines to reach cities.The power consumption in the urban areas is also high so government increases the price so the people can utilise the electricity smartly.Therefore, there were some reasons I have discussed above for the higher electricity cost in urban areas.
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is the gravity of the sun and moon pull earth's surface in the same direction neap or spring
Through which of these media do sound waves travel most slowly? A.iron. B.Wood. C.Water. D.Cold Air
Among the given materials, sound waves will slowly passes through water. Because, water is denser than a wood, air and a metal. Thus option C is correct.
What are sound waves?Sound waves are mechanical waves that are energy transfer through a medium such as air, water etc. Mechanical waves unlike electromagnetic waves need a medium to propagate.
Sound waves are longitudinal waves, where the oscillation of particles is along the propagation of waves. The speed of waves through a medium depends on the density of the medium.
The more denser the medium is speed of wave will be less. Moreover in liquids, the molecules are apart and the propagation of sound will be difficult . But through a metal and wood sound waves can travel easily. Hence, option C is correct.
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~Dissolved oxygen is required by all aquatic life.
~Chlorophyll, a plant pigment, is measured to indicate the amount of algae in the water.
~Nitrogen and phosphorous are nutrients that can contribute to undesirable levels of algae.
~Benthic invertebrates, animals that live on the bottom of water bodies, are an important source of food for fish, shrimp and crabs.
Georgia's overall coastal habitats were rated and the results can be seen in the bar graph. Benthic organisms are an important link in an aquatic food chain. What is the expected correlation between the benthic index and chlorophyll a?
A) There is no correlation between benthic organisms and chlorophyll a. One group is plant-based; the other is animal-based.
B) There is a direct correlation between algae present and benthic organisms. The more algae, the more benthic invertebrates.
C) As benthic organisms decrease we would expect chlorophyll a to also decrease. There is a direct relationship between the two in the graph.
D) As chlorophyll a increases, we would expect dissolved oxygen to decrease and because benthic organisms are animals, they too would decrease.
The answer is D. As chlorophyll a increases, we would expect dissolved oxygen to decrease and because benthic organisms are animals, they too would decrease.
A mathematical equation that predicts how a physical phenomenon will behave
Final answer:
A mathematical equation predicting physical phenomena is a scientific law, which includes formulas like the Law of Conservation of Energy. Mathematical models and dimensional analysis also play roles in understanding and predicting physical systems.
Explanation:
A mathematical equation that predicts how a physical phenomenon will behave is often referred to as a scientific law. These laws are descriptions, frequently formulated mathematically, which represent the outcomes of repeated experiments or observations within a specific context. For instance, the Law of Conservation of Energy, which is a fundamental concept in physics, can be summarized by a mathematical equation that is crucial for understanding energy transfer and transformation in a closed system.
In the context of physics and engineering, mathematical models are instrumental in outlining physical phenomena using mathematical frameworks like equations and inequalities. Dimensional analysis is one method that utilizes basic principles of dimensions and can help in qualitatively understanding physical systems and predicting quantitative responses to changes in parameters, even with limited detailed knowledge of the system.
A city planner needs to verify that Main Street and Oak Street are parallel. If ___________ are supplementary, the streets must be parallel. A) ∠1 and ∠2 B) ∠1 and ∠3 C) ∠2 and ∠3 D) ∠2 and ∠4
Answer;
A) ∠1 and ∠2
Explanation;
Supplementary angles form a straight line and have a sum of 180 degrees. Supplementary angles do not have to be congruent or adjacent. Angle 1 and angle 2 are supplementary angles.
Complementary angles on the other hand are two angles whose sum is 90 degrees. Supplementary and complementary angles do not have to be adjacent (sharing a vertex and side, or next to), but they can be. angles sum right angle.
The baking soda looked like it dissolved in the vinegar. Sarah and Connor watched as the balloon expanded and filled with a gas. Was this a physical or chemical reaction and why? A) chemical - gas produced B) physical - water bottle got hot C) physical - baking soda dissolved D) chemical - baking soda disappeared
Answer: A) chemical - gas produced
Explanation: Physical change is a process in which there is no change in chemical composition of the substance.
Chemical change is a process in which there is a change in chemical composition of the substance.
Chemical process is accompanied by following changes
1. Change in color
2. Absorption or release of energy
3. Production of gas
4. Formation of precipitates.
Thus a chemical reaction is happening on mixing baking soda [tex](NaHCO_3)[/tex] and vinegar [tex](CH_3COOH)[/tex], there is production of [tex]CO_2[/tex] which expanded the balloon.
[tex]NaHCO_3+CH_3COOH\rightarrow CH_3COONa +CO_2(g)+H_2O[/tex]