A chemistry teacher is able to grade chemistry labs at a rate of 5 labs for every 3 minutes. They need to grade 165 labs how many hours will it take?​

Answers

Answer 1

Answer:

1.65hr

Explanation:

Given parameters:

Number of labs  = 5 labs

 Time taken  = 3 minutes

Unknown:

Time taken in hours to grade 165 labs  = ?

Solution:

Let us find the rate of the teacher;

  Rate  = [tex]\frac{number of labs}{time}[/tex]  

  Insert the parameters and solve;

   Rate  = [tex]\frac{5}{3}[/tex]   = 1.67labs/min

Now;

   Time to grade 165 labs  = [tex]\frac{number of labs}{rate}[/tex]  

   Time to grade 165 labs  = [tex]\frac{165}{1.67}[/tex]   = 98.8min

  Since;

               60min = 1hr

               98.8min  = [tex]\frac{98.8}{60}[/tex]   = 1.65hr


Related Questions

How to do this question plz answer me ​

Answers

Answer:

  dissolved

Explanation:

The figure shows sodium chloride is in solution. It gets that way by being dissolved.

calculate the ph of a solution whose(oh^-) is 4.583*10^-5 mole dm cube (pkw=14)​

Answers

pH of solution = 9.661

Further explanation

pH is the degree of acidity of a solution that depends on the concentration of H⁺ ions. The greater the value the more acidic the solution and the smaller the pH.

pH = - log [H⁺]

So that the two quantities between pH and [H⁺] are inversely proportional because they are associated with negative values.

pOH=-log[OH⁻]

[tex]\tt pOH=-log[4.583\times 10^{-5}]\\\\pOH=5-log~4.583=4.339[/tex]

pH+pOH=pKw

[tex]\tt pH=14-4.339\\\\pH=9.661[/tex]

What is the frequency of a photon with an energy of 3.38 x 10-19 J?​

Answers

Hey There!_____________________________________Answer:

[tex]\huge\boxed{5.1x[tex]10^{14}[/tex]Hz}[/tex]

_____________________________________DATA:

E = [tex]3.38 x 10^{-19}[/tex]

h = [tex]6.625x10^{-34}[/tex]

f = ?

_____________________________________SOLUTION:

Energy of Photon is given by,

                                   

                                   E = hf

Rearrange the equation,

                             

                                    f = [tex]\frac{E}{h}[/tex]

where,

           E = energy

           h = planck's constant

           f = frequency

------------------------------------------------------------------------------------------------------------

Substitute the variable in the equation,

 

                                 f = [tex]\frac{3.38x10^{-19}}{6.62x10^{-34}}[/tex]

Simplify the equation,

                               

                                  f = 5.10 x 10^14 Hz          

                         

_____________________________________Best Regards,'Borz'

Answer:

b. 5.10 x 10^14 Hz

Explanation:

Please help me how do i solve this

Answers

Answer:120

Explanation:2gfdxxfgngfnf

What color are the stars on the diagram with the lowest surface temperatures?

Answers

Answer:

red supergiants is the answer

paragraph on water cycle

Answers

Answer:

The water cycle or hydrologic is a continuous cycle where water evaporates, travels into the air and becomes part of a cloud, falls down to earth as precipitation, and then evaporates again. ... These areas are usually close to oceans or large bodies of water that allow more water to evaporate and form clouds.

Explanation:

Directions: Read through each scenario and identify the independent variable, dependent variable, and the control.

Question 1

1 pts

Rob is in charge of waxing the floor at the local mall. He wants to test a new brand of floor wax called

Squeaky Clean. Rob waxes 20 floor tiles with Squeaky Clean and 20 tiles with the original wax brand.

After one week he counts the number of scratches on the floor. What is the independent variable?

number of floor scratches

brand of floor wax

20 tiles with original brand wax

Answers

Answer:

The correct answer is - brand of floor wax.

Explanation:

The independent variable is the variable or the factor in an investigation which is manipulated or change in the experiment and affects the dependent variable and produces a various result.

In this investigation, there are different brands of the floor was are the independent variable as they are changed to see the effect on the scratches on the floor on 20 tiles for each brand.

An isotope of Cesium -137 has a half-life of 30 years. If 1.0 g of Cesium – 137 disintegrates over a period of 60 years, how many grams of Cesium- 137 would remain?

Answers

Answer:

Explanation:

Radioactive decay follows the equation:

Ln [A] = -kt + ln [A]₀

Where [A] is amount of isotope after time t: Our incognite,

k is rate constant: ln 2 / Half-life = 0.0231 years⁻¹

t are 60 years

[A]₀ is initial amount of isotope: 1.0g

Replacing:

Ln [A] = -kt + ln [A]₀

Ln [A] = -0.0231 years⁻¹*60 years + ln 1.0g

ln [A] = -1.386

[A] = 0.25g

The density of lead is 11.4g/cm3. What volume, in ft3, would be occupied by 10.0 g of lead?

Answers

Answer:

The volume is 3.09 ft^3.

Explanation:

The formula for volume is mass divided by density. 10.0 g / 11.4 g/cm^3 = 0.87719. Converted to cubis foot is 3.09 ft^3. I hope this helps you.

A state property X has a value 89.6 units. It undergoes the following changes, first increase by
3.6 units, then increase by another 18.7 units, then decrease by 12.2 units and finally attains a
value of 85.5 units The value for this series of change is A) 14.2 units
B) -4.1 units C) 108.3 units
D) uncertain​

Answers

Answer:

B) -4.1 units

Explanation:

According to this question, a state property X has a value 89.6 units. It undergoes the certain changes as follows:

- first increase by 3.6 units

- then increase by another 18.7 units

- then decrease by 12.2 units

- and finally attains a value of 85.5 units

This can be mathematically represented by 89.6 - {3.6 + 18.7 - 12.2 - x) = 85.5

To get x, we say;

89.6 + 3.6 = 93.2

93.2 + 18.7 = 111.9

111.9 - 12.2 = 99.7

99.7 - 85.5 = 14.2units.

The changes that occured is represented as follows:

= (3.6 + 18.7) - (12.2 + 14.2)

= 22.3 - 26.4

= -4.1 units

After pollen grows on a tube down the style,___

Answers

Answer:

as soon as the pollen reaches the stigma after the pollen grain descends down the style when the pollen tube grows into the ovule when the seed germinates

Explanation:

Dating of Rock Layers
Answer all 12 questions relating to the images below
English (US)
100

Answers

Answer:

I'm sorry, we need the image to answer  it.

Explanation:

Help please If there are 10 moles of HCl gas occupying 15L at 350°C, what is the pressure? Be sure to show the setup and
the final answer and unit.
Show Your Work

Answers

Answer:

P = 34.1 L

Explanation:

Given data:

Number of moles = 10 mol

Volume occupy = 15 L

Temperature = 350°C

Pressure of gas = ?

Solution:

The given problem will be solve by using general gas equation,

PV = nRT

P= Pressure

V = volume

n = number of moles

R = general gas constant = 0.0821 atm.L/ mol.K  

T = temperature in kelvin

Now we will convert the temperature.

350+273 = 623 K

by putting values,

P×15 L = 10 mol ×0.0821 atm.L/ mol.K ×623 K

P = 511.48atm.L/15L

P = 34.1 L

Which of these changes to a modern lifestyle would promote the
development of more-sustainable practices in the world food system?
O A. Switching from chicken to beef
B. Eating fewer processed foods
O C. Buying tropical fruits
D. Eating fresh vegetables year-round

Answers

I think it’s B. At least that’s what makes sense to me

Eating fewer processed foods would promote the development of more-sustainable practices in the world food system.

What are Processed food?

This is the food which has undergone some degree of alteration during preparation such addition of preservatives etc.

Eating less of it will ensure that more sustainable practices in the world food system are promoted.

Read more about Processed food here https://brainly.com/question/21201084

#SPJ2

Hydrogen bond is not formed by 1) oxygen 2) nitrogen 3) chlorine
PLEASE HELP!!!

Answers

Answer:

Input work is the work done on a machine as the input force acts through the input distance. This is in contrast to output work which is a force that is applied by the body or system to something else. Output work is the work done by a machine as the output force acts through the output distance.Jan 15, 2020 bahsgsh bvshgs d hg

the number of molecules in 7g nitrogen​

Answers

Answer:

the number of molecules in 7g nitrogen

Ans) 7 gram of Nitrogen contains 1.5×10^23 molecules =1.5e+23

arrange the following in order of increasing mass . a. 16 water molecules b. 2 atoms of lead 3. 5.1*10^-23​

Answers

the answer is b i just took the test

Given the following equation,
HCl aq) + NaOH aq
NaClaq) + H2O(l)
How many moles of H20 will be produced if there are 5 moles of HCI?​

Answers

Answer:

5 moles

Explanation:

Given data:

Number of moles of HCl = 5 mol

Number of moles of H₂O produced = ?

Solution:

Chemical equation:

HCl + NaOH     →   NaCl + H₂O

Now we will compare the moles of HCl with H₂O.

                          HCl            :           H₂O

                             1               :             1

                             5               :            5

5 moles of water will be produced.

What will happen to the flow of blood in blood vessels (pulse) if heart beat rate increase

Answers

Answer:

"Low levels of the hormone epinephrine, also called adrenaline, cause blood vessels to relax and widen. High levels of this same hormone, along with the hormone norepinephrine, cause the blood vessels to narrow and the heart rate to rise, increasing blood pressure."

Explanation:

Which of the following sets of forces acting on an object will result in the object moving?
5 Newtons Up and 5 Newtons Down
31 Newtons Left and 32 Newtons Right
0 Newtons Up and 0 Newtons Down
9 Newtons Left and 9 Newtons Right

Answers

Answer:

31 N left and 32 N right because

Explanation:

It’s the only one movement because when you subtract them there’s still 1 left

Which of these is an example of chemical separation of a substance?
-Distillation
-Magnetism
-Paper Chromatography
-Bond breaking

Answers

Answer:

Bond broking

Explanation:

Bond broking.

When propane is reacted in the presence of oxygen gas, the products of this combustion reaction are: A. CO + H2O B. CO2 + H2O C. C2H4 + H2O D. CH4 + H2O

Answers

Answer:

B. CO2 + H2O

Explanation:

Propane is an hydrocarbon as it contains only v=carbon and hydrogen atoms.

Whenever an hydrocarbon reacts with oxygen or undergoes a combustion reaction, two products are always formed only,

These two products are;

Carbon dioxide (CO2) and water (H2O)

This means the correct option is option B.

Momentum is mass times

A. acceleration
B. velocity
C. distance

Answers

B. velocity

This is the answer

State the number of degrees of longitude that separates New York City from Denver, Colorado between these two cities.

Answers

Answer:

The number of degrees of longitude that separates New York City from Denver, Colorado is 30.9843 degrees longitude

Explanation:

The longitude of New York City is 74.0060° W

The latitude of New York City is 40.7128° N

The longitude of Denver, Colorado is 104.9903°W

The latitude of Denver Colorado is 39.7392°N

Therefore, the difference the number of degrees of longitude that separates New York City from Denver, Colorado is 104.9903 - 74.0060 = 30.9843°.

helpppppp i hate chemistry
I will give brainiest who helps me with the correct answer
I promise

5. Name the compound which contain Strontium, Fluorine, and Oxygen.

Options:

Strontium fluorate
Strontium fluoride
Strontium chlorate
Strontium fluorine

Answers

Answer:

The first option: Strontium Fluorate.

Explanation:

because Fluorine and oxygen combines to make fluorate, Strontium stays the same.

p.s: i need help in geo and there's an exam tomorrow.

How many grams are equal to 0.11 mole of copper(I) chromate?

Answers

Mass of Copper(I) chromate( CuCrO₄) = 19.75 g

Further explanation

The mole is the number of particles contained in a substance

1 mol = 6.02.10²³

Moles can also be determined from the amount of substance mass and its molar mass

[tex]\tt \large{\boxed{\bold{mol=\dfrac{m(mass)}{MW(molecular~weight)}}}[/tex]

0.11 mole of Copper(I) chromate( CuCrO₄) ⇒ MW=179.54 g/mol, so mass :

[tex]\tt mass=mol\times MW\\\\mass=0.11\times 179.54\\\\mass=19.75~g[/tex]

Why is NCl3 not soluble in water?

Answers

Answer:

Explanation:

NCl3 does not dissolve in water because it is a nonpolar molecule which is different with water. NCl3 is nonpolar due to the difference in electronegativities between 3 atoms of Cl and 1 atom if N2.

Answer:

A polar solute dissolves into a polar solvent and a non-polar compound dissolves into a non-polar solvent, this rule is known as "like dissolves like".

1. What part of the human body has the same role as the power source in a computer?

2.What part of the human body has the same role as the keyboard or the mouse on a computer?

Answers

Answer:

The heart

Hand

Explanation:

The part of the human body that has the same role as the power source in a computer is the heart. A power source in a computer provides energy that powers the whole system.

The human heart provides the pumping action for the circulatory system. Just like current passes through wires in a computer by energy from the power source, the human heart pumps blood throughout the body in a like manner. Without the pumping action of the heart, the human body is dead.

Also, keyboard and mouse are input devices. They are used to give instruction and perform certain tasks on the computer system.

The human body can also carryout tasks by using the hand. Objects are moved from one place to another just as you drag an icon using the mouse. We type word processors using information from the keyboard, also, we are able write using pen on paper.

describe a habitat of giraffe or an elephant(i prefer the giraffe tho, and please make it reasonable)

Answers

Answer:  Savanna, Woodland, or Grassland.

Giraffes eat new shoots and leaves, their habitat needs to have a good supply of trees -- they flock towards acacia trees in particular. Giraffes use their extremely long legs, necks and tongues to browse mainly from the thorns on the acacia tree. The tongue and the inside of the mouth are lined with tough tissue that protects against the thorns.

Please Help!!!

Which of the following is not a good indication that a chemical change has occurred?
A. The formation of gases
B. A change in color
C. A scratched surface
D. The release heat or light​

Answers

Answer:

C.

Explanation:

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