# Posts by John

Total # Posts: 8,424

**Chemistry**

An aqueous solution containing 17.1 g of an unknown molecular compound ( nonelectrolyte) in 105.0g of water was found to have a freezing point of -1.8 degrees Celsius. What is the molar mass of the unknown compound?

**Advanced Functions/Precalculus**

Trigonometry Questions 1. Using a compound angle formula, demonstrate that sin2π/3 is equivalent to sin π/3 2. The expression sinπ is equal to zero, while the expression 1/cscπ is undefined. Why is the identity sin(theta)=1/csc(theta) still an identity? 3. ...

**first year chem**

There are two naturally occurring isotopes of chlorine with ratios of 76% and 24%. One mole of PCl3 is made using a sample of isotopically pure chlorine gas (containing only one of the two isotopes). The product weighs 142 g. If chlorine gas containing the other isotope were ...

**Advanced Functions/Precalculus**

Trigonometry Questions 1. Using a compound angle formula, demonstrate that sin2π/3 is equivalent to sin π/3 2. The expression sinπ is equal to zero, while the expression 1/cscπ is undefined. Why is the identity sin(theta)=1/csc(theta) still an identity? 3. ...

**Advanced Functions/Precalculus**

thanks! i forgot to include the exponent. I re-typed them here: 2. Solve the equation 7sin^2x-4sin2x/cosx=-1 where 0≤x≤2π 3. Determine the exact value of cos2(theta) when tan(theta)=3/4 and π<theta<3π/2 4. The average number of customers, c, at...

**Advanced Functions/Precalculus**

Trigonometry Questions 1. Solve the equation sin2x+1=-2sinx for 0≤x≤2π 2. Solve the equation 7sin2x-4sin2x/cosx=-1 where 0≤x≤2π 3. Determine the exact value of cos2(theta) when tan(theta)=3/4 and π<theta<3π/2 4. The average ...

**Advanced Functions/Precalculus**

Trigonometry Questions 1.) Find the exaqct value of tan(11π/12) 2.) A linear trig equation involving cosx has a solution of π/6. Name three other possible solutions 3) Solve 10cosx=-7 where 0≤x≤2π

**Geometry**

How is the size of a TV measured? If we are comparing a 15-inch TV and a 30-inch TV, what is twice as big about the bigger TV?

**math**

Mrs. Smith had 1/2 of a pumpkin pie left over. She split the leftover pie evenly between her 3 children. What fraction of pie did each child get?

**Geometry**

To determine the relationship between miles and kilometers, if we use the conversion 39.37 inches= 1 meter, we find that 1 kilometer is approximately equal to 0.62 mile. What if we use the conversion 2.54 centimeters = 1 inch? How far apart are the answers (1 kilometer = x ...

**physics**

A child and sled with a combined mass of 53.0 kg slide down a frictionless hill that is 7.63 m high. If the sled starts from rest, what is its speed at the bottom of the hill?

**AP Physics**

A 67.0 kg diver steps off a diving board and drops straight down into the water. The water provides an upward average net force 1480 N. If the diver comes to rest 4.7 m below the water's surface, what is the total distance between the diving board and the diver's ...

**AP Physics**

A 67.0 kg diver steps off a diving board and drops straight down into the water. The water provides an upward average net force 1480 N. If the diver comes to rest 4.7 m below the water's surface, what is the total distance between the diving board and the diver's ...

**Physics Classical Mechanics**

anyone solved this ?????

**Algebra**

For the integers from 1 to 1000, how many multiples of 9 are also multiples of 6?

**physics**

A monatomic ideal gas is thermally insulated, so no heat can flow between it and its surroundings. Is it possible for the temperature of the gas to rise? If the temperature can rise, how does it rise?

**math**

For the integers from 1 to 1000, how many multiples of 9 are also multiples of 6?

**communicate**

consider an artifact that is prominently displayed by a friend or co-worker - either at home or in some other space. In 1-2 paragraphs, explain how this artifact has influenced your interpretation of this person's identity. Is your perception more positive or negative ...

**Calculus**

An observer stands at a point P, one unit away from a track. Two runners start at the point S in the figure and run along the track. One runner runs 2 times as fast as the other. Find the maximum value of the observer's angle of sight è between the runners. Thank ...

**Solar Energy**

Formula in first question: a)Pmpp < Voc X Isc Formula in second question: Load resistance = Vmpp/Impp

**Solar Energy**

With respect to a PV module's I-V and P-V curves, and the module's operating point, consider the following statements: a) When the operating point of the PV module is on the MPP (maximum power point), \(P_{mpp} \lt V_{oc} \times I_{sc} \) b) For a given Irradiance and ...

**Math**

Thanks Ms. Sue!

**Math**

What is the smallest positive composite integer?

**Comm 215**

Do these look correct? Part I: True or False 1. The following word group is a FRAGMENT: That movie, one of my favorites. _X_True __False 2. The following word group is a FRAGMENT: The local baseball team, needing a good pitcher most of all. _X_True __False 3. The following ...

**math**

how can you use the product of 12 x 6 to find the product of 12 x 12 ?

**chemistry**

A mixture of NaCN and NaHSO4 consists of a total of 0.60 mol. when the mixture is dissolved in 1.0 L of water and comes to equilibrium the pH is found to be 9.9. Find the amount of NaCN in the mixture.

**math**

Find recursive and explicit formula for -40 -36 -32 -28

**Liquid capacity of pitcher**

1 quart

**Science**

A pelican flying along a horizontal path drops a fish from a height of 125 m while traveling 40 m/s. How far does the fish travel horizontally before it hits the water below?

**Statistics**

this makes no sense, u said which would be inferential and which would be inferential

**science**

Chemistry Hey guys, i have a question about how to figure out how much mass of a compound i need to find 130ppm here is the question. What mass of Fe(NH4)2(SO4)2*6H2O is required to prepare 2.25 L of a 130 ppm iron solution? Now i know that ppm is (mg of desired compound)/(kg ...

**Chemistry ppm**

Oh okay, I understand. Wow thanks alot.

**Chemistry ppm**

Hey guys, i have a question about how to figure out how much mass of a compound i need to find 130ppm here is the question. What mass of Fe(NH4)2(SO4)2*6H2O is required to prepare 2.25 L of a 130 ppm iron solution? Now i know that ppm is (mg of desired compoun)/(kg of solvent ...

**chemistry**

OH is correct haha sorry i read that wrong um well C is incorrect same as D, B is incorrect because if the constituent is the first number than you wouldnt use the number 1 plus its a methyl as the first carbon making it decane and then A is the only correct one for reasons ...

**chemistry**

4,5-dimethylpentane is incorrect, not only is it not using the lowest constituents numbers in the name I.E. using 1,2 instead of 4,5 it is impossible to have a methyl constituent on the first or last carbon because that would just mean the compound is not a pentane but in fact...

**Math**

Well W = 3 L = (2W)-5 = (6) - 5 = 1 so W + W + L + L = perimeter so 2W + 2L = perimeter so subbing 2W-5 in for L we get 2W + 2(2W-5) = perimeter = 2W + 4W-10 = perimeter = 6W - 10 = perimeter = 6(3) - 10 = perimeter =18 - 10 = perimeter = 8 = perimeter or solving the other way...

**Chemistry**

i dnt see any relevant equations, i don't know how u expect someone to help you also is strain a spring constant? too much information is lacking

**criminal**

1. local police should be prohibited from arresting or detaining persons for the sole purpose of investigating their immigration status. 2. Officers should arrest persons who violate the criminal laws of their jurisdictions without regard to immigration status of the alleged ...

**physics**

A 160 kg child jumps at 7 m/s into a boat floating a rest. After the jump, they both move at 3 m/s forward. Find the boat's mass.

**science**

Ms. sue, shut up, he isn't cheating he was answering the kid's question, get off his back and get a life

**phyics**

A glass bottle of soda is sealed with a screw cap. The absolute pressure of the carbon dioxide inside the bottle is 1.60 x 105 Pa. Assuming that the top and bottom surfaces of the cap each have an area of 3.60 x 10-4 m2, obtain the magnitude of the force that the screw thread ...

**phyics**

18m

**English**

also mood coward

**English**

is sarcasm one

**English**

which poetic device does this quote use “Why no one on our side had even thought of firing a gun, because when you came right down to it, we didn’t like guns and did not believe in them”

**First year chem**

It was on a test and computer wasn't allowed.

**First year chem**

Barium has 6 stable isotops (132Ba, 134Ba, 135Ba, 136Ba, 137Ba, and 138Ba) with natural abundances ranging from 0.1% for least abundant to 71.7% for the most abundant. Which isotope of barium is the most abundant? (Answer is 138Ba) Thank you for your help!!

**PRE-CALC HELP**

1) Two boats leave the same port at the same time. One travels at a speed of 27 mi/h in the direction N 50° E and the other travels at a speed of 22 mi/h in a direction S 70° E (see the figure). How far apart are the two boats after one hour? (Round your answer to the ...

**PRE-CALC HELP**

Two boats leave the same port at the same time. One travels at a speed of 31 mi/h in the direction N 50° E and the other travels at a speed of 20 mi/h in a direction S 70° E (see the figure). How far apart are the two boats after one hour? (Round your answer to the ...

**PRE-CALC HELP**

A communications tower is located at the top of a steep hill, as shown. The angle of inclination of the hill is 58°. A guy wire is to be attached to the top of the tower and to the ground, 150 m downhill from the base of the tower. The angle α in the figure is ...

**physics**

Water is flowing down through the pipe shown in the drawing. Point A is 0.410 m higher than B. The speed of the water at A and B are vA = 5.00 m/s and vB = 3.80 m/s. Determine the difference PB - PA in pressures between B and A. The density of water is 1.00x10^3 kg/m3.

**math**

Flawed question. 3 answers to this: 1200:like Ms.Sue answered 700: in they mean June, July, & Aug. Or 500 if they mean between May(200) + Sept. (300) = 500. Common Core stinks!!

**geography**

What are some reasons why society, especially in the U.S., has been more and more accepting of the view of global warming? Please post to these questions by the end of Week 3.

**physics**

a)188 Nm^2 b)77m

**chemistry**

Assuming reaction goes to completion, determine the final concentration of NH4Cl in the calorimeter. heat capacity =3.03J/g.c density =1.012 5g of NH4Cl used 100 mL of water used NH4Cl(s) + H2O(l) --> NH4Cl(aq)

**math**

HOw can i explain this to a 4th grade student as it seems her teacher did not do the number substitution like W and dividing to get the answer.

**math**

the girls high school basketball team played 12 games. they won 6 more games than they lost. find the number of games the basketball team won.

**ashford**

Mrs. Orlof teaches two history classes, one in the morning and one in the afternoon. Yesterday she gave the same test to both classes. Anyone who failed the test must take a retest. Since a greater percentage of students who took the morning test failed the test than students ...

**Algebra**

-2 |h-7|= -28

**chemistry**

Compared to the particles of a gas, the particles of a liquid are not in constant motion collide with the sides of the container, but not with each other do not completely fill their container can move longer distances have more space in between the molecules

**Physics**

MASS PUSHED BY A SPRING A block of mass m=2 kg on a horizontal surface is connected to a spring connected to a wall (see figure). The spring has a spring constant k= 16 N/m. The static friction coefficient between the block and the surface is μs= 0.7 , and the kinetic ...

**Medical Billing and Coding**

CAN I KNOW THE ANSWER FOR THIS QUESTION?

**math**

A small wheel of radius r is situated at the top of a ramp having an angle Î¸ = Ï€/3 rad At t = 0 the wheel is at rest and then it starts to rotate clockwise in the positive x direction with constant angular velocity Ï‰. Find the parametric ...

**informal logic**

Which of the following may not qualify as a falsifiable claim? (Points : 1) Your luck will improve. Your house will be sold tomorrow. Granite is more dense than sand. Smoking may cause heart disease.

**Algebra**

a car repair shop charge $80 per hour for labor and $210 for the parts of a car . if the total cost of repair for the car was $490 , how many hours did it take ro repair the car ?

**Probability**

7. The random variable X is distributed normally with a mean of 12.46 and variance of 13.11. You collect a random sample of size 37. a. What is the probability that your sample mean is between 12 and 13? b. What is the probability that a single observation is between 12 and 13...

**chemistry**

Based on the calculations above, which of the following equations is the one represented by this experiment? Justify your answer by comparing the moles of iron consumed and the moles of copper produced to the coefficients in the equation of your choice. (16 points) Fe + CuCl2...

**Social studies**

"There capitols"? Really? You're a teacher? How about "their capitols"? And your map left off the capitol of Mississippi altogether.

**physics**

A person jumps from the roof of a house 4.0-m high. When he strikes the ground below, he bends his knees so that his torso decelerates over an approximate distance of 0.66m. If the mass of his torso (excluding legs) is 42kg , what is the magnitude of the average force exerted ...

**Science**

I have too much swaggg

**Physics**

A car is parked on a cliff overlooking the ocean on an incline that makes an angle of 22◦ below the horizontal. The negligent driver leaves the car in neutral, and the emergency brakes are defective. The car rolls from rest down the incline with a constant acceleration ...

**physics**

A place kicker must kick a football from a point 34.0 m (about 37 yd) from the goal. As a result of the kick, the ball must clear the crossbar, which is 3.05 m high. When kicked, the ball leaves the ground with a speed of 21.0 m/s at an angle of 56◦ to the horizontal. To...

**Math- URGENT**

find the value of x or y so that the line through the points has the given slope. (12,y) and (15,-8); slope: 2/3

**Chemistry**

Is a more negative corrosion potential more susceptible to corrosion or a less negative corrosion potential?

**science**

What keeps the very dense gas at the core of the Sun from becoming a solid?

**English ---- check grammar---**

I know that looks like a long paragraph . I wrote it like a essay , but when i post it , it changed all my style and space !!! I don't know why !

**English ---- check grammar---**

Can you guys check grammar for me ? Thank you!

**English ---- check grammar---**

When I was fifteen years old, I left the Vietnam to begin a new life with my family in the United States. But my young heart has never stopped yearning for that one day when I would go back home. One peculiar thing about Vietnamese is that they associate homesickness with ...

**5TH GRADE MATH**

50*2 = 100 100/3 = 33 1/3

**5TH GRADE MATH**

Um...Stephon could you stop typing in caps?

**5TH GRADE MATH**

basically we need to find the greatest whole number to be given out to each student. so, 3 to each student means 3 + 3 +3 or 3* 3 = 9. There are 10 pencils, so 10-9 = 1 remaining pencil.

**milli**

What's the question, my good man?

**Trigonometry**

Yes sir, this is supposed to be a precalculus problem. Thanks

**Trigonometry**

Find all x such that 0< = x <= pi/2 and sin^7 x + cos^7 x = 1. (Be sure to show that no other values of x satisfy the equation. Remember, x is in radians.) I'm confused. I posted this before but my thick skull couldn't absorb the answer I was given. Could someone...

**Please help mrs Sue**

I'm pretty sure it's A.

**Biology**

Which of the following cells check for during the G2 check point? a. Growth hormone c. DNA integrity b. Nutritional status d. Cell size In mitosis, if a cell has 4 chromosomes in prophase, how many chromosomes will this cell have in metaphase? a. 64 b. 32 c. 16 d. 8 e. 4 The X...

**Trigonometry - Slopes stuff**

Point A is the terminal point of angle phi and point B is the terminal point of angle theta. Point A is in the first quadrant and point B is in the second quadrant, while tan phi = 1 and tan theta = -7. Find the slope of AB. Ok so since A is in the first quadrant and tan phi...

**Math**

You are making a recipe that consists of 5 different ingredients. In how many different orders can you add the ingredients to the bowl?

**quantum physics**

Well, technically, they could cheat via email so it's not exactly a better way per se, however, yes that is cheating I suppose.

**math**

What would be your answer after all these problems?

**Statistics**

In probability and statistics, mean is used to refer to one measure of the central tendency either of a probability distribution or of the random variable characterized by that distribution. In statistics and probability theory, the standard deviation (represented by the Greek...

**math**

Yerp

**math**

Whoops, I meant 100/100 - 21/100 = 79/100 100/100 + 6/100 = 106/100 79/100 * 106/100 * 44 = ?

**math**

Do what you did on the previous problems :P 100/100 - 21/100 = 79/100 100/100 - 6/100 = 94/100 79/100 * 94/100 * 44 = ?

**Math**

Actually, that would be 1.23 x 10^-10. Move it over one more place. Count 11 places from 1.23. From 1.23 to 0.123 there is one jump.

**Math**

This means: how many times larger is a proton then an electron? Thus we put the proton on the numerator and the electron on the denominator. From pure chemical science, a proton is wayyy bigger (and heavier) than an electron. Thus, if you get an answer that is really small ...

**math**

Oh right, I'm sorry.

**math**

We need a 17% discount. We need a 5% discount as well. These discounts are on something valued at $89. If you have a 17% discount, it means you get 100/100 - 17/100 = 83/100 off the original price. In the same way, if you have a 5% discount, it means you have a 100/100 - 5/100...

**Physics**

What do you say?