Answer:
The kinetic energy of the two curling stones is 320 J
Explanation:
Given;
mass of the first curling stone, m₁ = 20 kg
velocity of the first curling stone, v₁ = 4 m/s
velocity of the second curling stone, v₂ = - 4m/s
assuming the second curling stone to have equal mass with the first stone = 20 kg
The kinetic energy of the first curling stone is given by;
K.E₁ = ¹/₂m₁v₁²
K.E₁ = ¹/₂(20)(4)²
K.E₁ = 160 J
The kinetic energy of the second stone is given by;
K.E₂ = ¹/₂m₂v₂²
K.E₂ = ¹/₂ (20) (-4)²
K.E₂ = 160 J
Thus, the kinetic energy of the two curling stones is given by;
K.E = K.E₁ + K.E₂
K.E = 160 J + 160 J
K.E = 320 J
Therefore, the kinetic energy of the two curling stones is 320 J
which shows as evidence for a scientific claim. A- surveys of public opinion B- company advertisments C-controlled experiments D- personal websites
Answer:
A
You do not know if the advertisement is lying to you. Controlled experiments will be biased and personal websites will say what they think, not following the data & science.
Atoms contain positive, negative, and neutral. what happens when two positively charged particles are close together?
A.They repel each other
B.They cancel each other
C.They attract each other
D.They have no effect
Answer:
they repel each other
Explanation:
A is the ans
The density of plutonium is 19.84 g/cm². What is its mass if the container has
volume of 250 cm?
Answer:
the answer is 7.936X 10⁻⁷kg.... the unit for volume must be cm³
Explanation:
we know,
ρ =m/v
given,
ρ =19.84/1000X(100)²= 1.984X10⁻⁶kg/m²
V (volume of the container means the volume of the element)=2.5 m³
NOW putting in the equation
1.984X10⁻⁶/2.5=m
or, m=7.936X 10⁻⁷kg(ANS)
thank u(i am not 100% sure but think it shoud be the answer)
HELP ASAP!! A pebble is dropped into a graduated cylinder and the volume rises from 25.0 mL to 31.0 mL. The mass of the pebble is 2.9g. What is the density of the pebble? (g/mL)
Answer:
The density of the pebble is 0.483g/mL (rounded), but it's 0.48333333333333 without rounding. Hope this helped! :)
Explanation:
Volume= 6.0mL Density=Mass/Volume
Mass= 2.9g
D=2.9g/6.0mL
D=0.48333333333333g/mL
or
D≈0.483g/mL
A scientist studies living organisms in their natural setting
Answer:
did not
Explanation:
ask
Is this statement true or false? Why?
Chemical reactions are nothing more than rearrangements of protons.
Answer:
False. Answer in pic above
In fact protons have no role in chemical reactions. The regrouping of atoms itself forms the new products in chemical reactions. The reactions involves the loss/gain or sharing of electrons.
What is a chemical reaction ?A chemical reaction is a chemical change in which two or more atoms combine together to form a new product or a compound decomposes to form its constituent compounds. This involves breaking or making of bonds.
In a chemical reaction, no change occurs in the nuclear composition but the valence electrons are involved in the reaction. Atoms loss or gain electrons or share valence electrons with other atoms to form ne compounds.
The electrostatic force of attraction or the overlapping of atomic orbitals make the new products in a chemical reaction. Hence, the statement is false.
Find more on chemical reactions:
https://brainly.com/question/29039149
#SPJ2
If the density of a gold coin is 19.3g/cm3, what would be the density of the coin if you cut it in half?
How could contaminants from your community affect a river basin that is miles away?
contaminants from your community can flow through runoff into a river basin.
Contaminants from your community affect a river basin that is miles away could runoff can carry pollutants from your neighborhood into a river basin.
What is community?Community is defined as a social community that shares characteristics like geography, rules, beliefs, values, or identities. Community is important because they are frequently a significant source of social connection and a sense of belonging, strong communities are essential. Living a fulfilling life requires being a part of a group of people who share similar attitudes, values, and aspirations.
Contaminants are defined as a substance that, whether unintentionally or on purpose introduced to air, water, soil, or food, becomes detrimental to humans or other living things on a biological, chemical, physical, or radiological level. Chemical, physical, and biological pollution are the three different types.
Thus, contaminants from your community affect a river basin that is miles away could runoff can carry pollutants from your neighborhood into a river basin.
To learn more about community, refer to the link below:
https://brainly.com/question/19515708
#SPJ2
Which element has an atomic mass of 106.42?
Answer:
carbon
Explanation:
The element which has atomic mass of 106.42 is carbon as per the existing isotopes.
What is an element?
It is defined as a substance which cannot be broken down further into any other substance. Each element is made up of its own type of atom. Due to this reason all elements are different from one another.
Elements can be classified as metals and non-metals. Metals are shiny and conduct electricity and are all solids at room temperature except mercury. Non-metals do not conduct electricity and are mostly gases at room temperature except carbon and sulfur.
The number of protons in the nucleus is the defining property of an element and is related to the atomic number.All atoms with same atomic number are atoms of same element.
Learn more about element,here:
https://brainly.com/question/13025901
#SPJ5
Need help with this
Answer:
C option is the correct answer
What is the SI unit for mass
Answer:
kilo gram
Explanation:
kilogram(kg)
Answer:
Kilogram (Kg).......
what is an oxidation reaction?
Fe + O2 —(H2O)—> Fe2O3
how many bonds are broken in 2O2
Answer:
c5mvmifvidvj8dvj9r kf9,g
6.
Which best represents a particle containing 28 protons, 26 electrons, and 34 neutrons?
A Fe2-
B
54
2+
28N;
C%2Fe2-
DSNi2+
Answer:
Ni^2+
Explanation:
The following data were obtained from the question:
Proton = 28
Electron = 26
Neutron = 34
Next, we shall determine the atomic number of the element.
Atomic number of an element is simply defined as the number of protons in the atom of an element.
Thus,
Atomic number = proton number
Proton = 28
Atomic number = proton number = 28
Atomic number = 28
Therefore, the element is Nickel since no two elements have the same atomic number.
Finally, we shall determine the charge on the Nickel atom as follow:
Proton = 28
Electron = 26
Charge on atom =
Charge on atom = Proton – Electron
Charge on atom = 28 – 26
Charge on atom = +2
Therefore, we can represent the Particle as Ni^2+
Laboratory equipment is cleaned and properly stored after use primarily so that
Options are provided in the given question, so the complete question is as follows:
Laboratory equipment is cleaned and properly stored after use primarily so that —
A. chemical products can be measured and recorded as data
B. time is saved in setting up the next experiment
C. toxic materials can be kept in the laboratory
D. the possibility of contamination in the laboratory is minimized
Answer:
D. the possibility of contamination in the laboratory is minimized
Explanation:
After the completion of experiments, all the laboratory equipment should be cleaned and properly stored to minimize the possibility of contamination in the laboratory.
Any contamination in the laboratory can affect the experiment and will not give an accurate result, so it is important to clean and store the equipment properly.
Hence, the correct answer is "D".
Which of the following is a single replacement reaction?
( a. Ba(OH)2 + H2SO4 → BaSO4 + 2H2O
( b. 2Mg + O2 → 2MgO
(c. H2O+ CO2 → H2CO3
(d. Zn + H2SO4 → ZnSO4 + H2
Answer:
D.
Explanation:
A. is double replacement. Ex. AX + BY -> AY + BX
B. is synthesis Ex. A + B -> AB
C. is synthesis
D. is Single replacement -> A + BX -> Ax + B
- Study definitions and examples of these and that will help.
When zinc react with sulfuric acid, then zinc sulphate is formed. Zn + H₂SO₄ → ZnSO₄ + H₂ this reaction is replacement reaction.
What is replacement reaction ?One element in a molecule is replaced by another in a chemical reaction known as a single-displacement reaction, sometimes referred to as a single replacement reaction or exchange reaction.
One element in a compound is switched out for another in a single replacement reaction. In a double-replacement process, the anions or cations of two ionic compounds are switched. In a double-replacement reaction known as a precipitation, a solid precipitate is one of the products.
One ingredient replaces another comparable element in a compound in a single-replacement reaction.
Thus, option D is correct.
To learn more about replacement reaction, follow the link;
https://brainly.com/question/17970302
#SPJ5
What would be the charge of an ion with 9 protons, 10 neutrons, 10 electrons
Answer:
negative
Explanation:
Any atom whose number electrons are more than the number of protons in it will have a negative charge. Since in this case the electrons are 10 and protons are 9 the 9+ charge protons and 9- charge electrons cancel each other giving a final charge of negative.
The charge of an ion with 9 protons and 10 electrons and neutrons is -1 as there is one more electron in comparison to number of protons .
What is an ion?An ion is defined as an atom or a molecule which has a net electrical charge. There are 2 types of ions :1) cation 2) anion . The cation is the positively charged ion and anion is the negatively charged ion . As they are oppositely charged they attract each resulting in the formation of ionic bond.
Ions consisting of single atom are mono-atomic ions while which consists of two or more ions are called as poly-atomic ions . They are created by chemical interactions . They are very reactive in their gaseous state and rapidly react with oppositely charged ions resulting in neutral molecules.They are attracted to opposite charges.
Learn more about ions,here:
https://brainly.com/question/1488567
#SPJ2
which is the odd one out of clay pot , chalk , steel spoon and glass bowl(with explanation)
Answer:
chalk
Explanation:
most of them are utensils
Mr.Davies has requested that you wait for 10 more minutes is that informal or formal
Answer:
Formal
Explanation:
Answer:
I think its formal because the question looks a bit fancy by using all the present perfect tense..
hope this helped you
please mark as the brainliest ( if its correct)(ㆁωㆁ)
How does a scientist test their hypothesis?
Answer:
Conducting experiments and using the scientific method.
Explanation:
Scientists (and other people) test hypotheses by conducting experiments. The purpose of an experiment is to determine whether observations of the real world agree with or conflict with the predictions derived from a hypothesis. If they agree, confidence in the hypothesis increases; otherwise, it decreases.
What do you think happens to the matter in a food sample as it is burned?
Burning and other changes in matter do not destroy matter. The mass of matter is always the same before and after the changes occur. The law of conservation of mass states that matter cannot be created or destroyed
The thing that is happen in a food sample as it is burned is the chemical and physical change.
What is combustion reaction?Comubustion reactions are those reactions in which organic compound get burnt in the presence of oxygen for the formation of carbon dioxide gas and water molecule.
If the food sample contains the organic compound then it will convert into water and carbon dioxide gas and if it contains the matter in the form of inorganic compounds then it will convert into another product but having the same mass.
Hence if matter of food sample is burned then it will convert into small products as a result of physical or chemical change.
To know more about combustion reaction, visit the below link:
https://brainly.com/question/15246277
#SPJ2
Which best explains how photosynthesis is helpful to humans? It reduces the amount of harmful rays released by the sun. It increases the levels of carbon dioxide in the air. It provides oxygen for humans to breathe. It produces proteins, which humans can eat.
Answer:
it provides oxygen for the human to breathe
Explanation:
During photosynthesis plants absorbs carbon dioxide from the atmosphere and release oxygen into the air. Hence, it increases the level of oxygen for breath.
What is photosynthesis?Photosynthesis is a biological process by which green plants produce energy and molecular oxygen in leaf by the aid of light energy. The photoactive pigments chlorophyll in green leaves absorbs light energy sufficient for this process.
The photosynthetic reaction involves combination of carbon dioxide and water to form glucose and oxygen as written below:
[tex]\rm 6H_{2}O + 6CO_{2} \rightarrow C_{6}H_{12}O_{6} + 6O_{2}[/tex].
Therefore, photosynthesis decrease the level of carbon dioxide and increase the level of oxygen in the air . Thus, plant biomass helps us to provide oxygen to breath.
To find more on photosynthesis, refer here:
https://brainly.com/question/1388366
#SPJ5
What is the formula for Hydroxide
Answer:
OH-
Explanation:
it's consists of an oxygen and hydrogen atom held together by a covalent bond and carries a negative electric charge
Look at the unbalanced reaction below for the combustion of hydrogen gas. What needs to be done to balance the reaction? _ H2 + _O2 LaTeX: \longrightarrow⟶ _H2O
Answer:
The given equation H2 + O2 => H2O is not balanced as the oxygen atom on the right side do not have the same number of atoms as of the left side.
In a balanced equation, the number of atoms on both sides are equal. So in this case, we are required to change the coefficient in front of H2O, in order to make oxygen atom balance, for that we need to change the coefficient of H2 as well.
It means to make the given equation balance we need to change the coefficient in front of H2 and H2O.
Balance equation: 2H2 + O2 => 2H2O
Calculate the destiny of the object that has a mass of 453 g and occupies the volume of 225 cm3
A ( 2.01g/cm3
B( 5.00 g/cm3
C( 453 g/cm3
D( 228 g/cm3
density = 2.013g/cm3
Explanation:
density = mass/volume
density = 453g/225cm3
density = 2.013g/cm3
An ice cream company decides to make a new lower calorie flavor,but testers reported that the flavor wasnt as good as the original.Is this an example of trade off
Answer:
Yes, the given instance is an example of a trade-off.
Explanation:
The trade-off seems to be a strategy to minimize or surrender one or more favorable results in consideration for increasing either receiving other favorable results to optimize cumulative benefit or efficacy within such conditions.The above is indeed a trade-off since the participants are experimenting in exchange again for ice cream individuals have to enjoy. The ice cream manufacturer always gets a review of the technician in exchange for free ice cream.Which of these would have lowest kinetic energy
Boiling water
Ice water
Refrigerated water
Water at room temperature
Answer:
The answer is ice water, since the particles of a solid have very low kinetic energy.
Explanation:
Answer:
Iced water.
Explanation:
It's a solid. Within a given substance, such as water, particles in the solid state have the least amount of kinetic energy.
As water freezes, it does so because after thermal energy leaves the particles, the average translational+rotational kinetic energy decreases, but the total average kinetic energy does not... and the temperature does not change either.
4. m stands for....
a) millimeter
C) centimeter
b) meter
d) Liter
Answer:
meter
Explanation:
STATE TRUE OR FALSE
a) natural gas has a characteristic odour
b) natural gas is heavier than air
c) synthetic fibres, polymers, dyes are synthesized from petrochemicals
d) we should use convential bulb's instead if LED'S
e) emission of CO2 gas during burning of fossil fuels burn global warming
Compare which element would have larger first ionization energy: an alkali metal in Period 2 or an alkali metal in Period 4?
AW: I think it would be alkali metal on period 2
Answer:
An alkali metal present in period 2 have larger first ionization energy.
Explanation:
Ionization energy:
The amount of energy required to remove the electron from the atom is called ionization energy.
Trend along period:
As we move from left to right across the periodic table the number of valance electrons in an atom increase. The atomic size tend to decrease in same period of periodic table because the electrons are added with in the same shell. When the electron are added, at the same time protons are also added in the nucleus. The positive charge is going to increase and this charge is greater in effect than the charge of electrons. This effect lead to the greater nuclear attraction. The electrons are pull towards the nucleus and valance shell get closer to the nucleus. As a result of this greater nuclear attraction atomic radius decreases and ionization energy increases because it is very difficult to remove the electron from atom and more energy is required.
Trend along group:
As we move down the group atomic radii increased with increase of atomic number. The addition of electron in next level cause the atomic radii to increased. The hold of nucleus on valance shell become weaker because of shielding of electrons thus size of atom increased.
As the size of atom increases the ionization energy from top to bottom also decreases because it becomes easier to remove the electron because of less nuclear attraction and as more electrons are added the outer electrons becomes more shielded and away from nucleus. Thus alkali metal present in period 2 have larger ionization energy because of more nuclear attraction as compared to the alkali metal present in period 4.