Both diamond and graphite (i.e. pencil lead) consist of carbon atoms. They are only different in their crystalline structures. One carat or 0.20 g, of a high-quality diamond costs up to $5000, while 25 g of pencil lead may only cost $2. Determine the numbers of C-atom in diamond vs. graphite which can be obtained with $1.

Answers

Answer 1

Answer:

Moles of carbon atoms  = 3.33  ×  [tex]10^{-6}[/tex] mol

No. of atoms of C in Diamond  = 2.007 ×   [tex]10^{28}[/tex] atom

Atoms of graphite = 6.27 × [tex]10^{23}[/tex] Atoms

Explanation:

given data

Cost of 0.2g of diamond = $5000

Cost of 25 g of graphite = $ 2

solution

we know cost of 0.2g of diamond is $ 5000 so that for 1$

if buy 1$ = [tex]\frac{0.20}{5000}[/tex]

1$ = 4.0 × [tex]10^{-5}[/tex] g Carbon

and Moles of carbon atoms  is express as

Moles of carbon atoms = Given mass of Carbon ÷ atomic mass of C      .........1

Moles of carbon atoms  = 4.0  ×  [tex]10^{-5}[/tex]    g/ 2.0g

Moles of carbon atoms  = 3.33  ×  [tex]10^{-6}[/tex] mol

and

No. of atoms of C in Diamond = No. of moles × Avogadro NO    ..............2

No. of atoms of C in Diamond  = 3.33 ×   [tex]10^{-6}[/tex] mol × 6.022 ×   [tex]10^{28}[/tex]

No. of atoms of C in Diamond  = 2.007 ×   [tex]10^{28}[/tex] atom

Graphite

and wew have given Cost of 25 g of graphite is $2 so for but 1$ we get

for buy $1 = 25÷2  = 12.5 g Of graphite

Moles of graphite = 12.5÷12 = 1.04 mol

Atoms of graphite = 1.04 × 6.022 × 1023

Atoms of graphite = 6.27 × [tex]10^{23}[/tex] Atoms


Related Questions

The mass fractions of a mixture of gases are 15 percent nitrogen, 5 percent helium, 60 percent methane, and 20 percent ethane with a total mixture molecular weight of 16.12 kg/kmole. Determine the mole fraction of each constituent, the partial pressure of each constituent when the mixture pressure is 1200 kPa and the apparent specific heats of the mixture when the mixture is at room temperature.

Answers

Answer:

Explanation:

mass fraction N₂ : He : CH₄ : C₂H₆ : : 15 : 5 : 60 : 20

mole fraction  N₂ : He : CH₄ : C₂H₆ : : 15/28 : 5/4 : 60/16 : 20/30

mole fraction  N₂ : He : CH₄ : C₂H₆ : : .5357  : 1.25 : 3.75 : .67

Total mole fractions = .5357 + 1.25 + 3.75 + 0.67 = 6.2057

mole fraction of N₂ =  .5357 / 6.2057 = .0877

mole fraction of He = 1.25 / 6.2057 = .20

mole fraction of CH₄ = 3.75 / 6.2057 = .6043

mole fraction of C₂H₆ = .67 / 6.2057 = .108

Partial pressure = total pressure x mole fraction

Partial pressure of N₂ = 1200 kPa  x .0877 = 105.24 kPa

Partial pressure of He = 1200 kPa  x .20  = 240 kPa

Partial pressure of CH₄ = 1200 kPa  x  .6043  = 725.16 kPa

Partial pressure of C₂H₆ = 1200 kPa  x .108    = 129.6 kPa

Consider the following reaction where K. = 9.52 10 2 at 350 K.
CH,(g) + CC14(2)—2CH2Cl2(g)
A reaction mixture was found to contain 2.21*10-2 moles of CH4(E), 3.8710-2 moles of CC1,(g) and 1.06-10-2 moles of CH,C12(2), in
a 1.00 liter container
Is the reaction at equilibrium?
If not, what direction must it run in order to reach equilibrium?
The reaction quotient, Qc equals
The reaction
A. must run in the forward direction to reach equilibrium
B. must run in the reverse direction to reach equilibrium
C. is at equilibrium

Answers

Answer:

The correct answer is A :))

This group of fungi forms spores in a round structure on the end of a hyphae

Answers

Answer:

Is zygote fungi an option??

Answer:

zygote fungi

Explanation:

i got the answer right

If a machine has an AMA of 1 what does this tell you about the RF and EF?

Answers

Answer:

Although you might think of a machine as complex system of gears, drive belts and and a motor, the definition physicists use is much simpler. A machine is simply a device that does work, and there are only six different types of simple machines. They include the lever, the pulley, the wheel and axle, the screw, the wedge and the inclined plane.

Explanation:

The rate constant for a certain reaction is measured at two different temperatures:

temperature k
376.0 °C 4.8 x 10^8
280.0 °C 2.3 x 10^8

Assuming the rate constant obeys the Arrhenius equation, calculate the activation energy Ea for this reaction.

Answers

Answer: The activation energy Ea for this reaction is 22689.8 J/mol

Explanation:

According to Arrhenius equation with change in temperature, the formula is as follows.

[tex]ln \frac{k_{2}}{k_{1}} = \frac{-E_{a}}{R}[\frac{1}{T_{2}} - \frac{1}{T_{1}}][/tex]

[tex]k_1[/tex] = rate constant at temperature [tex]T_1[/tex] = [tex]2.3\times 10^8[/tex]

[tex]k_2[/tex] = rate constant at temperature [tex]T_2[/tex] = [tex]4.8\times 10^8[/tex]

[tex]E_a[/tex]= activation energy = ?

R= gas constant = 8.314 J/kmol

[tex]T_1[/tex] = temperature = [tex]280.0^0C=(273+280)=553K[/tex]

[tex]T_2[/tex] = temperature = [tex]376.0^0C=(273+376)=649K[/tex]

Putting in the values ::

[tex]ln \frac{4.8\times 10^8}{2.3\times 10^8} = \frac{-E_{a}}{8.314}[\frac{1}{649} - \frac{1}{553}][/tex]

[tex]E_a=22689.8J/mol[/tex]

The activation energy Ea for this reaction is 22689.8 J/mol

Witch regard to the ph scale, a solution with a ph . A. Lower than 7 is considered basic

Answers

Answer:

false

Explanation:

if it is lower than 7 It is acid

What is the edge length of a 377-g iron cube? (The density of iron is 7.86 g/cm^3, and the volume of a cube is equal to the edge length cubed.)

Answers

Answer:3.50 cm

Explanation:

Answer:

3.63cm

Explanation:

is magnesium oxide an ionic or covalent compound. what are the reasons?​

Answers

Answer:

ionic

Explanation:

the bonds that hold magnesium and oxygen together are formed between atoms that give electrons

Which of the following would make a solution?
A. Oil in water
B. Sugar in water
C. Ice in water
D. Sand in water
SUBM

Answers

The combination from the available option that will make a solution would be sugar and water.

What are solutions?

Solutions are obtained when solutes dissolve in solvents.

In other words, a solute must be able to dissolve in a solvent before a solution can be formed.

Oil and water cannot mix, and thus, cannot form a solution. Sand is insoluble in water and ice and water are the same.

Thus, the only option left is sugar and water. Sugar dissolves in water to form a sugar solution.

More on solutions can be found here: https://brainly.com/question/7932885

#SPJ2

Write the chemical formula for this molecule O=N-CI

Answers

Explanation:

Structural Formulas v. Empirical Formulas

An empirical formula (like a molecular formula) lacks any structural information about the positioning or bonding of atoms in a molecule. It can therefore describe a number of different structures, or isomers, with varying physical properties. For butane and isobutane, the empirical formula for both molecules is C2H5, and they share the same molecular formula, C4H10. However, one structural representation for butane is CH3CH2CH2CH3, while isobutane can be described using the structural formula (CH3)3CH.

Calculate the molar it’s of a solution containing 29g of glucose dissolved in 24.0 g of water

Answers

It would be 5g of glucose solution

Imagine a made-up pol

b. Write both the formula and the name for the compound formed when Cu2+

combines

with boritate? (2 pts)

Answers

Answer:

No change to the cation  Add -ide to the anion

Question 1 and .2

Explanation:

Calculate: Press Reset. Start with 1.900 × 10 24(or 19.00 × 10 23 ) molecules of Cu2O. A. Calculate the number of moles: B. Use the Gizmo to verify your calculation. Were you correct? C. Is the method for converting molecules to moles the same as that for atoms?

Answers

Answer:

1.661 mol.

Explanation:

Hello!

In this case, since the Avogadro's number allows us to relate the number of formula units in one mole of the substance; we need to keep in mind that elements are related by atoms and compounds by molecules, it means:

[tex]1 mol = 6.022x10^{23}atoms\\\\1 mol = 6.022x10^{23}molecules[/tex]

Thus, for copper (I) oxide, we compute the moles, given the atoms as shown below:

[tex]n = 1.900x10^{24}molecules*\frac{1mol}{ 6.022x10^{23}molecules} \\\\n = 1.661mol[/tex]

Thus, the method we use is the same.

Best regards

write the rate expression for the following reaction. H2+1/2
O2 arrow H2O​

Answers

Answer:

[tex]r=-k[H_2][O_2]^{1/2}[/tex]

Explanation:

Hello!

In this case, according to the chemical reaction:

H2 + 1/2  O2 --> H2O​

Since both hydrogen and oxygen are the reactants and the rate laws are written in terms of the concentration of reactants and the rate constant, we obtain:

[tex]r=-k[H_2][O_2]^{1/2}[/tex]

Whereas the negative sign represents the consumption of those reactants and the power 1/2 the stoichiometric coefficient of oxygen in the reaction.

Best regards!

What type of energy does a bouncing ball have ?

Answers

Answer:

Kinetic

Explanation:

When the ball is falling towards the table, it has kinetic energy. This elastic potential energy is why the ball is able to bounce, or rebound. After the ball rebounds, the elastic potential energy is transformed into kinetic energy, but it will never possess as much kinetic energy as during its original fall.

Answer:

Explanation:

It has kinetic energy.

Hope it helped you.

Number of liters in 0.50 moles of O2

Answers

Answer:

there are about 11.2 liters

Which of the following chemical reactions is a single displacement reaction?
A. 2Na + O2→
Na2O
B. 2A1 + 3Zn(NO3)2 2AI(NO3)3 + 3Zn​
C. Pb(NO3)2 + 2KBr → PbBr2 + 2KNO3
D. 2Fe(OH)3 Fe2O3 + 3H2O

Answers

Answer:

B. 2A1 + 3Zn(NO3)2 --> 2AI(NO3)3 + 3Zn​

Explanation:

In the chemical equation, you can see that 2Al replaced 3Zn with (NO3)3 in the product, thus it is a single displacement reaction.

Answer:

B. 2A1 + 3Zn(NO3)2 --> 2AI(NO3)3 + 3Zn​

Explanation:

What is the mole ratio between H2O and O2

Answers

The balanced equation is 2H2 + O2 –> 2 H2O. It takes two hydrogen atoms for every oxygen atom to produce this reaction, so the mole ratio between hydrogen and oxygen is 2:1

Answer is 2:1

What does an ion have that an atom does not?

Answers

Answer:

Atoms are neutral; they contain the same number of protons as electrons. By definition, an ion is an electrically charged particle produced by either removing electrons from a neutral atom to give a positive ion or adding electrons to a neutral atom to give a negative ion.

Explanation:

:)

what is a row of elements across the periodic table called

Answers

Answer:

a period

Explanation:

Answer: The row of elements across the periodic table is called "periods".

Explanation:

In the Periodic Table, there are seven rows of elements, which is called periods.

QUESTION 5
Which of the following is NOT electromagnetic wave?
O A. Sound wave.
O B. Microwave.
O C. Infrared wave.
O D. X-Ray.

Answers

i think A is the correct answer

Answer:

Beta Rays

Beta Rays are not Electromagnetic Waves

Beta rays also known as beta radiation is obtained through the emission of an electron. Beta rays are not electromagnetic waves because they are charged particles and are capable of getting deflected by the magnetic field.

An unknown solid is added to water in a calorimeter. The temperature of the water increases. What does this say about the reaction? A) The reaction is exothermic. B) The reaction is endothermic. C) The reaction has absorbed heat from the solution. D) The reaction has released heat to the solution. E) Both A and D are correct.

Answers

Answer:

Option A is correct.

Option D is correct.

E is the correct answer

Explanation:

This a theoretical calorimetry problem that can be solved by thermodynamic concepts.

Our system is the unknown solid. If the temperature of water has increased, we can think, that the heat from the metal was absorbed by water, which is our surrounding. If in the analysis of the situation we use a calorimeter, knowing that it is an isolated system, which does not allow the entry or exit of heat, we can conclude that the heat released is equal to the heat absorbed.

In conclusion, the thermodynamic system is constituted by the chemical reaction. In this case, the surrounding is made up of water and the calorimeter itself.

If the reaction is exothermic, the heat released by the reaction will be absorbed by the surrounding . Then, the final temperature will be higher than the initial temperature. If the reaction is endothermic, the heat absorbed by the reaction will be released by the environment. So, the final temperature will be lower than the initial temperature.

How many moles of KMnO4 are in 75g of KMNO4?

Answers

Answer:

0.64 mol

Explanation:

moles=mass/molar mass

n= 75/(39+14+4×16)

n=75/117

n = 0.64mol


5. If you advance the movie one frame, the knot at point A would be
a) in the same place b) higher
c) lower d) to the right
e) to the left
relative to the hand
6. If you advance the movie one frame, the pattern of the waves will be
a) in the same place
b) shifted right
c) shifted left
shifted up
e)
shifted down
7.
If the person starts over and moves his hand more quickly, the peaks of the waves will be
a) the same distance apart
b) further apart
c) closer together
8. If you lower the frequency of a wave on a string you will
a) lower its speed. b) increase its wavelength. c). lower its amplitude. d) shorten its period

Answers

Answer:

5. higher

6. shifted down

7. closer together  

8. increase its wave length

Explanation:

The following aqueous solutions of are mixed: 100.0 mL of 1.00 M lithium bromide and 100.0 mL of 1.00 M lead (II) nitrate. In an organized and clear manner, show all of your work and answers for this problem on the uploaded work. (a) Write the molecular equation for this reaction. (b) Write the total ionic chemical equation for this reaction. (c) Write the net ionic chemical equation for this reaction. (d) Identify the spectator ions in this reaction. (e) Identify the limiting reactant. (f) Determine the mass of solid product that is formed?

Answers

Answer and Explanation:

(a) When lithium bromide (LiBr) solution is mixed with a solution of lead (II) nitrate (Pb(NO₃)₂), lithium nitrate (LiNO₃) and lead (II) bromide (PbBr₂) are formed, according to the following molecular equation:

2LiBr(aq) + Pb(NO₃)₂(aq) → 2LiNO₃(aq) + PbBr₂(s) ↓

As the product PbBr₂ is an insoluble solid, it precipitates (↓).

(b) The total ionic equation is written with all ions of the reaction - no matter if they participate in the precipitate formation or not:

2Li⁺(aq) + 2Br⁻(aq) + Pb²⁺(aq) + 2NO₃⁻(aq) → 2Li⁺(aq) + 2NO₃⁻(aq) + PbBr₂(s)

(c) The net ionic equation is written including only the ions which participate in the precipitate formation. In this case, the precipitate is PbBr₂, and it is formed by Pb²⁺ and Br⁻ ions:

Pb²⁺(aq) + 2Br⁻(aq) → PbBr₂(s)

(d) The spectator ions are those which do not participate in the formation of the precipitate. From the total ionic equation, we can see that Li⁺ and NO₃⁻ ions are repeated on both sides of the equation, so they are redundant. Thus, the spectator ions are Li⁺ and NO₃⁻ ions.

(e) To identify the limiting reactant, we first calculate the moles of each compound as the product of the solution concentration and volume:

For LiBr:

C = 1.00 M = 1 mol/L

V = 100.0 mL x 1 L/1000 mL = 0.1 L

moles of LiBr = 0.1 L x 1.00 mol/L = 0.1 mol

The same for Pb(NO₃)₂:

C = 1.00 M = 1 mol/L

V = 100.0 mL x 1 L/1000 mL = 0.1 L

moles of Pb(NO₃)₂  = 0.1 L x 1.00 mol/L = 0.1 mol

From the total ionic equation, we can see that 2 mol of LiBr reacts with 1 mol of Pb(NO₃)₂ to give 1 mol of PbBr₂ (solid product). The stoichiometric molar ratio is 2 mol LiBr/1 mol Pb(NO₃)₂ and we have 0.1 mol of each reactant (0.1 mol LiBr/0.1 mol Pb(NO₃)₂= 1). As 2 mol LiBr/mol Pb(NO₃)₂ > 1 mol LiBr/mol Pb(NO₃)₂, LiBr is the limiting reactant.

(f) From the total ionic equation, we know that 2 moles of LiBr produce 1 mol of PbBr₂. To determine the mass of solid product (PbBr₂) formed, we first multiply the stoichiometric ratio (1 mol PbBr₂/2 mol LiBr) by the actual number of moles of limiting reactant we have (0.1 mol):

moles of PbBr₂ = 0.1 mol LiBr x (1 mol PbBr₂/2 mol LiBr) = 0.05 mol PbBr₂

Finally, we convert the moles of PbBr₂ to gram by using the molar mass of the compound:

Molar mass PbBr₂ = 207.2 g/mol + (2 x 79.9 g/mol) = 367 g/mol

grams of PbBr₂ = 0.05 mol x 367 g/mol = 18.35 g

Consider the following elementary reaction:

2NO(g) → N2O2(g)

Suppose we let k1 stand for the rate constant for this reaction, and k-1 stand for the rate constant of the reverse reaction. Write the expression that gives the equilibrium concentration of NO in terms of k1, k-1. And the equilibrium concentration of N2O2.

Answers

Answer:

[tex][NO]=\frac{k_{-1}}{k_1} [N_2O_2][/tex]

Explanation:

Hello!

In this case, since the reaction may be assumed in chemical equilibrium, we can write up the rate law as shown below:

[tex]r=-k_1[NO]+k_{-1}[N_2O_2][/tex]

However, since the rate of reaction at equilibrium is zero, due to the fact that the concentrations remains the same, we can write:

[tex]0=-k_1[NO]+k_{-1}[N_2O_2][/tex]

Which can be also written as:

[tex]k_1[NO]=k_{-1}[N_2O_2][/tex]

Then, we solve for the concentration of NO to obtain:

[tex][NO]=\frac{k_{-1}}{k_1} [N_2O_2][/tex]

Best regards!

Which of the following are correct for zero-order reactions?
A. A higher concentration of reactants will not increase the reaction rate.
B. The units for the rate constant and the rate of reaction are the same.
C. The rate of reaction does not equal the rate constant.
D. The concentration of the reactants changes nonlinearly.
E. A zero-order reaction slows down as the reaction proceeds.

Answers

Answer:

The answer is "Choice A and Choice B"

Explanation:

The Zero-Order reactions are usually found if a substrate, like a surface or even a catalyst, is penetrated also by reactants. Its success rate doesn't depend mostly on the amounts of the various reaction in this reaction.

Let the Rate = k

As [tex]\frac{dx}{dt} \ rate\ \ K_0[/tex] doesn't depend on reaction rate, a higher reaction rate does not intensify the reaction.

By the rate [tex]k_0 =\frac{dx}{dt},[/tex] the created based and the reaction rate is about the same.

Below statement are correct about zero order reaction.

higher concentration of reactants will not increase the reaction rate. The units for the rate constant and the rate of reaction are the same.

What is Zero order reaction?

Zero-order reaction is a chemical reaction in which the rate of chemical reaction does not change with increase or decrease in the concentration of the reactants.

Example is the decomposition of ammonia to nitrogen and hydrogen. the rate does not vary, it is the same.

Therefore, Below statement are correct about zero order reaction.

higher concentration of reactants will not increase the reaction rate. The units for the rate constant and the rate of reaction are the same.

Learn more about zero order reaction from the link below.

https://brainly.com/question/13314785

Based on your answers to Question 3 above, why do you think that, as a general practice, when antibiotics

(including azithromycin) are prescribed to adults, the same dose is usually given, regardless of weight of the

patient?

Answers

Answer:

See explanation below

Explanation:

Since question 3 is not here, I will answer based on a general perspective.

The dosage of most antibiotics and drugs generally are prescribed without considering the weight of adults. Unlike children that are given dosages based on their weight.

The weight of adults is not considered because the extent to which they weigh is majorly as a result of their adipose (fat) tissue. And the adipose tissue does not determine the tolerance level of drugs. So an adult weighing 200kg and another weighing 50kg will be able to tolerate the same dosage of medications.

Because the adults are adults with fully developed organs, their weight does not matter when prescriptions are made.

Why does heating increase the speed at which a solute dissolves in water?
O A. It decreases the surface area of the solute.
B. It prevents the solute from cristallizing.
O c. It makes the water molecules move faster.
D. It raises the pressure of the water molecules.

Answers

Answer: C

Explanation:

It gives kinetic energy to the molecules and it breaks the bonds faster because they jiggle more

A student assembles ball bearings that are 0.19 inches in diameter into an FCC lattice using glue which makes for a 0.001 inch thick bond between bearings. What is the lattice constant in inches of this FCC crystal? Three significant digits and fixed point notation.

Answers

Answer:

the lattice constant is 0.270 inches

Explanation:

Given the data in the question;

For FCC lattice;

a = b = c, ∝ = β = α = 90°

from the image below;

AC = 0.19 + 0.19/2 + 0.19/2 + 2(0.001) inch

AC = 0.19 + 0.095 + 0.095 + 0.002

AC = 0.382 inches

Now using Pythagoras theorem

AC² = AB² + BC²

since a = b = c

AC² = a² + a²

(0.382)² = 2a²

2a² = 0.145924

a² = 0.145924 / 2

a² = 0.072962

a = √0.072962

a =  0.27011 ≈ 0.270 inches

Therefore, the lattice constant is 0.270 inches

Other Questions
explain why the town in canada is colder than the amazon village Solve for x -12=-32+55 NEED HELP QUICK!!What does this translate to I can't find it anywhere. Plz help. Anna purchased a phone with a rectangular screen that measures 6,5 centimeters in width and 12 centimeters in length. She wants to know the diagonal measure ofthe screen. Round your answer to the nearest tenth of a centimeter6.5 cm12 cm What religious observance is expected of faithful Muslims at least once during their lifetime? A copper atom has an atomic number of 29 and an atomic mass of 64. What is the structure of this atom?A. It has a central nucleus composed of 29 protons and 35 neutrons,surrounded by an electron cloud containing 29 electrons.B. It has a central nucleus composed of 29 protons and 64 neutrons,surrounded by an electron cloud containing 29 electrons.C. It has a central nucleus composed of 35 protons and 29 neutrons,surrounded by an electron cloud containing 29 electrons.D. It has a central nucleus composed of 29 protons and 29 neutrons,surrounded by an electron cloud containing 35 electrons. Louis Pasteurs Publication of the Germ Theory was the biggest turning point in medicine in the period c1700-c1900How far do you agree with this statement?You may use the following in your answer:Edward JennerRobert KochYou must also use information of your own (20 marks) How can we use the study of genetics to help determine traits in organisms? Your answer must be in three complete sentences The following are the typical classifications used in a balance sheet: a. Current assets f. Current liabilities b. Investments and funds g. Long-term liabilities c. Property, plant, and equipment h. Paid-in-capital d. Intangible assets i. Retained earnings e. Other assetsRequired:For each of the following 2016 balance sheet items, use the letters above to indicate the appropriate classification category.1. Equipment2. Accounts payable3. Allowance for uncollectable accounts4. Land held for investment5. Notes payable due in 5 years6. Deferred rent revenue for the next 12 months7. Notes payable due in 6 months8. Income less dividend accumulated9. Investment in xyz corporation10. Inventories 11. Patents12. Land in use13. Accrued liabilities14. Prepaid rent for next 9 months15. Common stock16. Cash17. Building in use18. Taxes payable Son los que se produjeron en determinado periodo: los costos de los productos vendidos o los costos de los que se encuentran en proceso 27. What were the three rules for the colonists that came with James Oglethorpe? How does Shakespeare's selection of characters create a mood of evil and foreboding? Read the sentence and choose the option with the correct amount in the sentence.Los departamentos cuestan 700.590 pesos. Setecientos mil quinientos noventa Seiscientos mil seiscientos ochenta Ochocientos mil cuatrocientos setenta Quinientos mil trescientos cincuenta what is the constant of proportionality in y=3 and x=46.50plsssssssss help its for homework Which of the following three side lengths would form a triangleA)2 ft, 3ft, and 7ftB)3ft, 1 ft, and 2ftC)10ft, 5ft, and 7ftD)20ft, 10ft, and 5ft Does anyone know what the solid orange line represents? Agony refers to anguish. It refers to pain. The anguish is mental. The pain is intolerable.How do I combine those sentences? How do you divide -15/-5 7 The speed s can be found by dividing the distance d by time t. It took Kevin 3h traveling at an average speed of 45 mi/h from his house to Cooperstown.What is the distance between Kevin's house and Cooperstown? Help please I have no idea