Complete Question:
In ∆ABC, if sin A = 4/5 and tan A = 4/3, then what is cos A?
Answer:
[tex]cos A= \frac{3}{5}[/tex]
Explanation:
Given
[tex]sin A = 4/5[/tex]
[tex]tan A = 4/3[/tex]
Required
[tex]cos A[/tex]
In trigonometry;
[tex]tanA = \frac{sinA}{cosA}[/tex]
Multiply both sides by cosA
[tex]cos A * tanA = \frac{sinA}{cosA} * cos A[/tex]
[tex]cos A * tanA = sinA[/tex]
Divide both sides by tanA
[tex]\frac{cos A * tanA}{tanA} = \frac{sinA}{tanA}[/tex]
[tex]cos A= \frac{sinA}{tanA}[/tex]
Substitute values for sinA and tanA
[tex]cos A= \frac{4/5}{4/3}[/tex]
[tex]cos A= \frac{4}{5} / \frac{4}{3}[/tex]
[tex]cos A= \frac{4}{5} * \frac{3}{4}[/tex]
[tex]cos A= \frac{4 * 3}{5 * 4}[/tex]
[tex]cos A= \frac{3}{5}[/tex]
What is the main factor responsible for the acidic and basic character of oxides?
Explain your answer.
Explanation:
We define non-metal oxide acidity in terms of the acidic solutions formed in reactions with water. For example, sulfur trioxide reacts with water to forms sulfuric acid. In sum, acidic oxides are oxides of non-metals, and basic oxides are oxides of metals. ... CrO is basic, Cr2O3 is amphoteric and CrO3 is acidic.Reply me in comments3. What amount of
space is taken up by a rock that weighs 150 milligrams, and
has a density of 30 mg/ml? (Express your answer in Liters)
Hey there!:
Density = 30 mg/mL
Mass = 150 mg
Volume = ??
Therefore:
D = m / V
30 = 150 / V
V = 150 / 30
V = 5.0 mL
converts volume into liters :
5.0 mL / 1000 => 0.005 L or 5.0 x 10⁻³ L
Hope this helps!
Select the correct answer from each drop-down menu. At chemical equilibrium, the amount of because .
Answer:
The answer that completes the question are in BOLD:
At chemical equilibrium, the amount of PRODUCT AND REACTANT REMAIN CONSTANT because the RATES OF THE FORWARD AND REVERSE REACTIONS ARE EQUAL.
Explanation:
In a reversible chemical reaction, an equilibrium is said to be achieved when the rates of the forward reaction is equal to that of the reverse reaction. A reversible reaction is one in which products are formed from reactants simultaneously with the formation of reactants from products.
The combination of two or more substances called REACTANTS gives rise to another substance called PRODUCT, which can in turn give rise to Reactants again. With time, the rate at which the reactants give rise the products, which is called the FORWARD REACTION will be equal to the rate at which the products give rise to the reactants, which is called REVERSE REACTION. At this point, the chemical reaction is said to be in a STATE OF EQUILIBRIUM.
When the rate at which both reaction occurs becomes equal i.e. at an equilibrium state, the concentration of both the reactants and the products becomes constant i.e. no longer changes. Hence, the amount of the reactants forming the products is the same as the amount of products forming the reactants.
N.B: At chemical equilibrium, the amount of the reactants and products does not necessarily equals zero (0). It simply means that there is no net change in the concentration/amount of both reactants and products.
What is the equilibrium constant of aA+bB cC +dD?
Explanation:
{c}^C . {d}^D / {a}^A . {b}^B
If you have a little air in a balloon, find the volume of the balloon if the mass is 0.6 g and the density of the air is 0.0012 g / mL
Hey there!:
Mass = 0.6 g
Density = 0.0012 g/mL
Volume = ??
Therefore :
Density = mass / Volume
0.0012 = 0.6 / V
V = 0.6 / 0.012
V = 500 mL
Hope this helps!
Which of these scientist is know for his work in understanding climate change a : edwin hubble b : christian doppler c : warren washington d : charles kuen kao
Answer: just trust me its c
Explanation: i dont cap
What is ionic bond and explain it
Answer:
An ionic bond is a chemical bonding involving the attraction between oppositely charged ions
Explanation:
On the periodic table, elements from group 1 and 7 are attracted to each other and when they bond, it's called ionic bonding. This is because of their valence electrons and ions.
Answer:
Ionic bonding is a type of chemical bonding that involves the electrostatic attraction between oppositely charged ions, and is the primary interaction occurring in ionic compounds. It is one of the main types of bonding along with covalent bonding.
9.7300x10^2
+
9.8700x10^3
[?]x10^[?]
Answer:
1.0843×10^4
Explanation:
If we are to add 9.7300x10^2 + 9.8700x10^3, we must first make the powers of the both to be be the same so that we can carry out any mathematical manipulation of interest. So we can have;
9.7300x10^2 + 98.700x10^2
When we now add the both we have (9.7300 + 98.700)×10^2.
This now gives us the result, 108.43×10^2 which is correctly written as 1.0843×10^4, according to the rules of writing in scientific notation.
In the laboratory, a volume of 100 mL of sulfuric acid (H2SO4) is recorded. How many g are there of the liquid if its density is 1.83 g / cm3?
Answer:
[tex]\large \boxed{\text{183 g}}[/tex]
Explanation:
[tex]\begin{array}{rcl}\text{Density} & = & \dfrac{\text{Mass}}{\text{Volume}}\\\\\rho & = &\dfrac{m}{V}\\\\1.83 \text{ g$\cdot$ cm}^{-3} & = & \dfrac{m}{\text{100 cm}^{3}}\\\\m & = & \text{183 g}\\\end{array}\\\text{There are $\large \boxed{\textbf{183 g}}$ of sulfuric acid.}[/tex]
write the formula of three compounds which you know and name the elements in them
Answer:
[tex]\boxed{\sf{view \ explanation}}[/tex]
Explanation:
Compound definition:
A compound is a chemical substance formed by two or more chemically bonded elements.
Three compounds:
Water is a compound with the formula [tex]\sf H_2O[/tex].
Two hydrogen atoms and one oxygen atom is present in one molecule of water.
Sodium chloride or table salt is a compound with the formula [tex]\sf NaCl[/tex].
One sodium atom and one chlorine atom is present in one molecule of sodium chloride.
Ammonia is a compound with the formula [tex]\sf NH_3[/tex].
In one molecule of ammonia, one nitrogen atom and three hydrogen atoms are present.
Answer:
See below
Explanation:
Three compounds are:
1) [tex]\mathrm {H_{2}SO{4}}[/tex] [Sulfuric acid]
The elements in this compound are hydrogen (H) , Sulfur (S) and Oxygen (O).
2) [tex]\mathrm {NaOH}[/tex] [Sodium hydroxide]
The elements in this compound are Sodium (Na) , Oxygen (O) and Hydrogen (H).
3) [tex]\mathrm {HCl}[/tex] [Hydrochloric acid]
The elements are Hydrogen (H) and Chlorine (Cl).
What are the requirements of any hypothesis in science?
Answer:
A scientific hypothesis must meet 2 requirements:
Explanation:
A scientific hypothesis must be testable, and;
A scientific hypothesis must be falsifiable.
Examine the given reaction. NH4NO3(s) → NH4+(aq) + NO3–(aq) ΔH° = 25.45 kJ/mol ΔS° = 108.7 J/mol·K Which of the given is correct about the ΔG° at 25 °C?
A)+4,360 J
B)−6,942 J
C)−4,360 J
D)+6,942 J
Answer:
B)−6,942 J /mol
Explanation:
At constant temperature and pressure, you cand define the change in Gibbs free energy, ΔG, as:
ΔG = ΔH - TΔS
Where ΔH is enthalpy, T absolute temperature and ΔS change in entropy.
Replacing (25°C = 273 + 25 = 298K; 25.45kJ/mol = 25450J/mol):
ΔG = ΔH - TΔS
ΔG = 25450J/mol - 298K×108.7J/molK
ΔG = -6942.6J/mol
Right solution is:
B)−6,942 J /molOver the period of a few days, a hospital receives an overwhelming increase in the number of patients with food poisoning. How would a scientist respond to this increase in sick patients?
Answer:
Hey there!
A scientist would try to determine the cause of the food poisoning, and see if the people who got poisoned had anything in common, for example: they ate at the same restaurant, they are all people of a certain age, etc.
Let me know if this helps :)
calculate the weight of 3.491 into 10 to the power 19 molecules of cl2
Answer:
The mass of 3.491 × 10¹⁹ molecules of Cl₂ of Cl₂ is 4.11 × 10⁻³ grams
Explanation:
The number of particles in one mole of a substance id=s given by the Avogadro's number which is approximately 6.023 × 10²³ particles
Therefore, we have;
One mole of Cl₂ gas, which is a compound, contains 6.023 × 10²³ individual molecules of Cl₂
3.491 × 10¹⁹ molecules of Cl₂ is equivalent to (3.491 × 10¹⁹)/(6.023 × 10²³) = 5.796 × 10⁻⁵ moles of Cl₂
The mass of one mole of Cl₂ = 70.906 g/mol
The mass of 5.796 × 10⁻⁵ moles of Cl₂ = 70.906 × 5.796 × 10^(-5) = 4.11 × 10⁻³ grams
Therefore;
The mass of 3.491 × 10¹⁹ molecules of Cl₂ of Cl₂ = 4.11 × 10⁻³ grams.
which one of the following has the smallest atomic radius a)Mg2+ b)O2- c)Na+ d)F-
Answer:
Mg2+
Explanation:
o2- =2,8
mg2+ =2,8
na+ =2,8
f- =2,8
since they are all same it depends on protons.
mg2+ has least protons
3.490x 10^-3 + 1.100x10^-2
[?]x10^[?]
[tex]1.44\times 10^{-2}[/tex]
Explanation:
We need to find the value of [tex]3.49\times 10^{-3}+1.1\times 10^{-2}[/tex].
Here,
The first number is [tex]3.49\times 10^{-3}[/tex]
The second number is [tex]1.1\times 10^{-2}[/tex]
To add these numbers as follows :
[tex]3.49\times 10^{-3}+1.1\times 10^{-2}=0.01449\\\\=1.44\times 10^{-2}[/tex]
So, the value of [tex]3.49\times 10^{-3}+1.1\times 10^{-2}[/tex] is [tex]1.44\times 10^{-2}[/tex]
0.32 L is equal to how many mL
Find the density of a cube on Earth that weighs 1.5 kg and has a side-length of 10 cm.
Answer:
1.5g/cm³
Explanation:
density=mass÷volume
mass= 1.5kg (change into g) = 1500g
volume of the cube = 10×10×10 = 1000cm³
density= divide 1500g÷1000cm = 1.5g/cm³
Density= 1.5g/cm³YOUR WELCOME!
The density of the cube on Earth that weighs 1.5 kg and has a side length of 10 cm is 1.5g/cm³
What is density?"Density is the mass per unit volume. Density is a scalar quantity. It is denoted by d and the symbol for density is given as rho, a Greek symbol. Density is calculated as mass divided by volume."
density = mass / volume
The mass of the cube on earth is 1.5 kg
The side length of the cube is 10 cm.
The mass is given in kg. It is converted into grams.
mass= 1.5kg (change into g) = 1500g
A cube is a three-dimensional square, it has 6 faces, so its volume will be calculated completely.
Volume of the cube = 10×10×10 = 1000cm³
Putting the values in the formula of density
density= divide 1500g /1000cm = 1.5g/cm³
Thus, the density of the cube on Earth is 1.5g/cm³.
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Human lungs have evolved to breathe oxygen at a pressure as that in the atmosphere, 0.21 atm. If a particular heliox mixture to be carried by a scuba diver is at a pressure of 7.00 atm, what should be the partial pressure due to helium in order to maintain the pressure due to oxygen at 0.21 atm?
Answer:
6.79 atm
Explanation:
Applying Dalton's law of partial pressure:
[tex]P_{total} = P_{helium} + P_{oxygen}[/tex], where [tex]P_{total}[/tex] = total partial pressure of all the component gases in the mixture, [tex]P_{helium}[/tex] = partial pressure of helium gas, and [tex]P_{oxygen}[/tex] = partial pressure of oxygen gas.
From the illustration, [tex]P_{total}[/tex] = 7.00 atm and [tex]P_{oxygen}[/tex] = 0.21 atm. Hence, the partial pressure due to helium is calculated such that:
[tex]P_{helium}[/tex] = [tex]P_{total} - P_{oxygen}[/tex]
= 7.00 - 0.21
= 6.79 atm
Therefore, the partial pressure due to helium in order to maintain the pressure due to oxygen at 0.21 atm would be 6.79 atm.
List the metals Mg, Cu, Au, Na and Al in the decreasing order of their reactivity with air.
Answer:
Na is most reactiveAlcuAu is less reactiveIN HEREAnswer:
Potassium (K)
Sodium (Na)
Calcium (Ca)
Magnesium (Mg)
Aluminium (Al)
Iron (Fe)
Lead (Pb)
Copper (Cu)
Silver (Ag)
Gold (Au)
When an object falls toward the ground due to gravity, what type of energy becomes kinetic energy?
Answer:
potential energy (gravitational)
Explanation:
Potential energy is the energy that is stored in an object due to its position relative to some zero position. An object possesses gravitational potential energy if it is positioned at a height above (or below) the zero height. If we think of the ground as the zero height, the height of the object is coming down from a positive height. Wherever it is relative to the zero height, it is stored at that height, meaning that it is potential energy at that particular height. When it moves to the ground, it becomes kinetic, by gravitational means.
Answer:
Potential
Explanation:
If two solutions with concentrations of 0.4 M sugar and 0.7 M sugar respectively are separated by a semipermeable membrane, during osmosis there is a net flow of Group of answer choices sugar molecules from the dilute to the concentrated solution sugar molecules from the concentrated to the dilute solution water molecules from the concentrated to the dilute solution water molecules from the dilute to the concentrated solution
Answer: Water molecules from the dilute to the concentrated solution
Explanation:
During Osmosis if a solution is separerated by a semipermeable membrane, the solvent (typically water) from the less concentrated solution in terms of solute goes through the semipermeable membrane to the solution with the higher concentration so that the concentrations between the solutions can be balanced.
With the above solutions therefore, water molecules would move from the solution of 0.4M of sugar to the solution with a 0.7M of sugar through the semipermeable membrane.
During osmosis, water molecules move from the dilute to the concentrated solution.
OSMOSIS:
Osmosis is the movement of water molecules from a region of higher concentration (low concentration of solute) to a region of lower concentration (higher concentration of solute). The principle of movement is based on the concentration gradient i.e. difference in concentration across a semipermeable membrane. According to this question, two solutions have sugar concentrations of 0.4 M sugar and 0.7 M respectively and are separated by a semipermeable membrane. Therefore, water molecules will move from the dilute (0.4M) to the concentrated (0.7M) solution during osmosis.Learn more at: https://brainly.com/question/13655668?referrer=searchResults
Please Help !!! Calculate the density water, if it takes up 237 mL and the mass is 237 g.
Hey there !
Mass = 237 g
Volume 237 mL
Therefore:
Density = mass / Volume
D = 237 / 237
D = 1.0 g/mL
Hope this helps!
What is the outcome of all chemical changes when two substances are combined?
Answer:
This is called a chemical reaction. gas may form.heat may be produced and the color may change
What happens during an alpha decay?
Answer:
Alpha decay is a type of radioactive disintegration in which unstable atomic nucleus releases a helium nucleus or alpha particle and transform into a different element. The new element formed will be reduced by four and the atomic number will be reduced by two.
Example of alpha decay is: Uranium 238 transform into Thorium 234 with the emission of an alpha particle.
take an onion and one jam bottle insert the roots of onion in the jam bottle for five days . after five days observe the growth in the roots of onion which is submerged in jam bottle. write observation here
Answer:
It is noticed that after five days, there is elongation of the root cells in the roots of onion in the jam bottle
Explanation:
It is noticed that after five days, there is elongation of the root cells in the roots of onion in the jam bottle. The growth of a plant is due to the availability of the growing and dividing cells in the meristematic regions of the apical meristems. (stem cells). This site are active site for elongation and differentiation of the stem tissues. In the apical meristem of the root cells, the cells have the potential to carry out mitosis and cell division repeatedly in order to generate newer cells for extension and development of stems and leaves. With each cell division, one cell remains in the meristem which the other increases in size and differentiate due to different genomic expression to form the meristem regions which eventually becomes the stem structure.
Which of the following is not an antioxidant _________
1) Sodium benzoate 2) Sulphur dioxide 3) Sulphite salts 4) Citric acid
Answer: 1. Sodium Benzoate
Explanation: An anti-oxidant is a substance that can help prevent or stop the damage done by free radicals. Examples include; Sulphur Dioxide, Sulphite Salts, Citric Acid, e.t.c
Sodium benzoate is a pure preservative.
Consider the hypothetical chemical reaction represented by the equation 3 A + 2 B → A 3B 2 Which of the following is a correct interpretation of this equation? i. 3 grams of A react with 2 grams of B to form 1 gram of A 3B 2 ii. 3 atoms of A react with 2 atoms of B to form 1 molecule of A 3B 2 iii. 3 moles of A react with 2 moles of B to form 1 mole of A 3B 2
Answer:
iii. 3 moles of A react with 2 moles of B to form 1 mole of A 3B 2
Explanation:
A + 2 B → A 3B 2
A chemical equation among other things, gives the stoichiometry of the reaction; that is the relationship between reactants and products.
This relationship is basically stated in moles form the coefficients of the reactants and product.
From the reaction above, we can say;
1 mol of A reacts with 2 mol of B to form 1 mol of A3B2
It cannot be grams because the reactants and products all have different molar masses.
The correct interpretation of the equation of the hypothetical chemical reaction is; Choice (iii) 3 moles of A react with 2 moles of B to form 1 mole of A 3B 2.
Definition:
Chemical equations are equations that make use of chemical formulae and symbols to represent chemical reactions. The left-hand side of a chemical equation represents the reactants and the right-hand side represents the products.
Each reacting entity is also assigned its corresponding stoichiometric coefficient.
However, this stoichiometric coefficient is to quantify the no. of moles of the reactants consumed or products formed as the case may be.
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Match the set of measurements of the boiling point of water with the best
description.
Measurements
Description
6. 103 °C, 90 °C, 101 °C
a.
Precise
7. 100 °C, 99 °C, 100 °C
b.
Accurate
8. 105 °C, 106 °C, 105 °C
c. Both accurate and precise
9. 99 °C, 101 °C, 100 °C
d. Neither accurate nor precise
Answer:
Matching
6.D
7.A
8.C
9.B
Explanation:
Took test
103 °C, 90 °C, 101 °C Neither accurate nor precise, 100 °C, 99 °C, 100 °C are Precise, 105 °C, 106 °C, 105 °C are Both accurate and precise, 99 °C, 101 °C, 100 °C are Accurate. These are the correct set of measurements of the boiling point of water.
what are boiling point and melting point ?The melting point is defined as the temperature at which solid and liquid phases are at equilibrium state, whereas the boiling point is defined as the temperature at which the pressure of a vapor of a liquid is equal to the external pressure.
Melting point in which the melting of solid occur to become a liquid at a given temperature, here the molecules gain enough amount of kinetic energy to get the intermolecular forces to convert into another form.
In case of Boiling point the liquid phase enters into the gaseous phase, when the external pressure is high than a temperature for the vapor pressure equal to the external pressure.
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ANSWER ASAP WILL GIFT BRANILIEST Which of the following happens to a molecule of an object when the object is cooled? A Its temperature increases. B It loses kinetic energy. C Its size increases. D It moves faster.
Answer:
It loses kinetic energy.
Explanation:
The definition of heat is molecules moving fast, so it cooling would mean they slow down.
Answer:
B, It loses kinetic energy.
Explanation:
