Tuesday

March 31, 2015

March 31, 2015

Total # Posts: 107

**perpendicular vectors**

Find two unit vectors each of which is perpendicular to vectors (1, 1, 0) and (1,0,1) What I did: a x b = (1, -1, -1) |axb|=square toot 3 correct answer is +/- (1/√3 - 1/√3 - 1/√3) or =+/- 1/√3 (1, -1, -1)
*February 11, 2015*

**Cross Product of Vectors**

Find a unit vector perpendicular to a=(4,-3,1) and b=(2,3,-1) What I did: a x b = ((-3)(-1)-(3)(1), (1)(2)-(-1)(4), (4)(3) - (2)(-3)) =(0,6,18) Answer is (0, 1/square root 10, 3/square root 10)
*February 9, 2015*

**Vectprs and Scalars**

Why are some of these scalars and others are vectors? What's the difference and how can you tell? 1. a dot (b x c) 2. (a dot b) x (b dot c) 3. (a + b) dot c 4. a x (b dot c) 5. (a x b) dot (b x c) 6. (a + b) x c 7. a dot (b dot c) 8. (a x b) + (b x c) 9. (a x b) - c 10. a ...
*February 9, 2015*

**Vectors/Scalars?**

is (u dot v)dot (a dot c) a scalar quantity or vector quantity? What's the difference? (I'm thinking scalar since it has no direction and it only has magnitude.)
*February 8, 2015*

**Vectors and Math**

Find x, y, and z if 2(x,-1,4)-3(-4,y,6)-1/2(4,-2,z)=(0,0,0) What I did: (2x,-2,8)-(-12,3y,18)-(2,-1,1/2z)=(0,0,0) (2x-14,-1-3y,-10-1/2z)=(0,0,0) Textbook answer is -5, -1/3, -20
*February 8, 2015*

**dot product of vecotrs**

Question: Find (3a+b)dot(2b-4a) if a=-i-3j+k and b=2i+4j-5k I did: =3(-1,-3,1)+(2,4,-5)dot 2(2,4,-5)-4(-1,-3,1) =(-3,-9,3)+(2,4,-5)dot(4,8,-10)-(4+12,-4) =(-1,-5,-2)dot(0,-4,-6) =(0,20,12) =0+20+12 =32 The text book answer is -80. What did I do wrong/
*February 7, 2015*

**Math: Intro to Vectors**

but the left side has a negative sign in between the x and y, and if you multiply it by -2, it makes the x negative.
*February 3, 2015*

**Math: Intro to Vectors**

Left side = right side check type of question. x - (x + y)/2 = (x - y)/2 What I did was times the x in the left side by 2. I got: =(2x-x+y)/2 which equals =(x+y)/2 But the left side is (x-y)/2. What am I doing wrong?
*February 3, 2015*

**Vectors**

if a=3x+2y and b=5x-4y, find x and y in terms of a and b What I did: 2a=6x+4y +b=5x-4y --------- 2a+b=x 2(3x+2y)+(5x-4y)=x 6x+4y+5x-4y=x 11x=x 11x dvided by x = 11 ...that isn't the correct answer. The correct answer (according to text book) is x=2/11a+1/11b y=5/22a-3/22b ...
*February 2, 2015*

**Chemistry**

Calculate the normal boiling point of a compound that has a vapor pressure of 19.30kPa at 167 Fahrenheit and a vapor pressure of 1.86kPa at 77 Fahrenheit.
*January 27, 2015*

**Math**

(2/3)y= 15-6 (2/3)y=9 2y=3(9) 2y=27 y=27/2 y=13.5 To Check: Plug y back into equation (2/3)(13.5) +6=15
*November 3, 2014*

**biology/cells**

Plant, animal, bacteria and protist cells all can use sugar to make energy Plant cells and bacterial cells can use photosynthesis and animal cells do cellular respiration (more specifically- glycolysis).
*November 3, 2014*

**Civic**

Country A has always focused on producing cotton. Country B is a producer of coffee, grain, and textiles. Based only on this information, which statement is true about these two countries? (1 point) Country A exports more than Country B. Country A has a more diversified ...
*June 2, 2014*

**Social Studies**

How is affirmative action related to education and students?
*March 23, 2014*

**Social Studies**

I found to things: 1) that it limited the number of immigrants in the country 2) that it required a certain number of minority to be hired. Which one of the two is it?
*March 23, 2014*

**Social Studies**

What is a quota system?
*March 23, 2014*

**Social Studies**

What is affirmative action?
*March 21, 2014*

**English**

Hi can you check my topic sentences? Antigone and Creon argue as she fights for the gods and he fights for his beliefs, resulting in the division of the city. Despite of the many warnings he receives, Creon’s discounting of prophecy produces destruction due to his ...
*February 28, 2014*

**Algebra 1**

Subtract them so the x's cancel out. Then solve for y, and plug it back in.
*February 28, 2014*

**Geometry**

Find the area of the circle than multiply it by the height to get your answer.
*February 28, 2014*

**science**

A lever scale is balanced with a beaker filled of air on one side. The scale is very sensitive and can easily measure a change in weight of about 1/2 mg. What happens If you put your finger carefully into the beaker without touching the glass?
*February 16, 2014*

**physical science**

Vi up = 10 sin 60 = 8.66 m/s if ax is horizontal acceleration, there is none. Horizontal component of velocity is constant
*February 15, 2014*

**science**

Hello Damon i have asked my teacher and he said that the air part is not what you said. He gave me one more chance to tell him what is the right answer.
*February 13, 2014*

**science**

A lever scale is balanced with a partially filled glass of water on one side. Will the balance be upset (and if so how?) if you put your finger carefully into the water without touching the glass? What happens if the beaker is filled with air instead of water?
*February 13, 2014*

**English**

ok thank you.
*January 10, 2014*

**English**

What is the tone in "The Bungrass Edge of the World" By Annie Proulx?
*January 10, 2014*

**English**

thank you. You should read it. it is interesting
*January 2, 2014*

**English**

would the tone for "The Life You Save May Be Your Own" by Flannery O'Conner be selfish because Mr. Shiftlet wants the car only and the mother is looking for any man to hand her daughter to?
*January 2, 2014*

**College**

What id the difference between University of maryland college park and University of Maryland Baltimore? I know they are at different locations but which one has what? I looked online but got so many different answers that i got confused.
*December 11, 2013*

**Health/profession**

thank you
*December 10, 2013*

**Health/profession**

when i looked at UMD, it said Pre-Medicine (Allopathic, Osteopathic, Optometry, Podiatry). What does that mean? I looked up the words, but I dont know why it is placed there though.
*December 10, 2013*

**Health/profession**

If I wanted to become a cardiovascular surgeon, would I take pre-medicine for osteopathic?
*December 10, 2013*

**physics**

A merry-go-round (pictured) is sitting in a playground. It is free to rotate, but is currently stationary. You can model it as a uniform disk of mass 200 kg and radius 110 cm (consider the metal poles to have a negligible mass compared to the merry-go-round). The poles near ...
*December 7, 2013*

**eng 1511**

He thought that he could afford to pay his own school fees.
*August 22, 2013*

**help please**

Two six sided dice were rolled, and a friend tells us that the numbers that came up were identical. Find the probability that the sum of the numbers was as follows: a) 4 b) 11 c) an even number d) an odd number
*July 7, 2013*

**math**

John has 2 coins, one fair and the other unbalanced so that the probability of its coming up heads is 2/3. He picks one of the coins at random, tosses it, and it comes up heads. What is the probability that he picked the unbalanced coin?
*July 7, 2013*

**math**

Three boxes, labeled A,.B. C, contain 1 red and 2 black balls, 2 red and 1 black balls, and 1 red and 1 black ball, respectively. Compute the terminal probabilities by using the multiplication technique. Then add the terminal probabilities for all the outcomes in which the ...
*July 7, 2013*

**math**

A card is drawn from an ordinary deck of 52 cards, and the result is recorded on paper. The card is then returned to the deck and another card is drawn and recorded. Find the probability that the following occurs: a) the first card is a diamond b) the second card is a diamond ...
*July 7, 2013*

**algebra**

a) 143/5544 b) 2808/5544 c) 2736/5544
*July 7, 2013*

**4th grade math**

So what I think is that first you havr to add 4 to the number you are starting with and keep on going. Basically you are skip counting by 4 but is starting on the number you are given.
*January 14, 2013*

**English-CItation**

MLA 7th edition..I am using citation machine I dont know which one of the categories I need to use because I need to show the pages too...
*December 21, 2012*

**math**

On three tests you earned grades of 88%,94% and 90%. Each test was worth 150 points. The final exam is worth 250 pts. How many pts do you need on the final exam to earn 93% of the total points on tests? What percent do you need on the final?
*December 4, 2012*

**math**

The final exam is worth 250 points. How many points do yu need on the exam to earn 93% of the total points ? What percent do yu need on the final?
*December 4, 2012*

**math**

how do you get the percent of 1 over 12
*November 27, 2012*

**Algebra**

The equation is 5= -z - 3 Why is the answer -8 and not just positive 8? Please explain the whole negative variable thing.
*September 4, 2012*

**Chemistry**

What mass of ice would you have to add to water to get the same change in temperature as if you add 7.55 grams of dry ice to water if they both started at the same temperature?
*April 17, 2012*

**physics**

a 43.7 kg student runs down the sidewalk and jumps with a horizontal speed of 4.48 m/s onto a stationary skateboard. the student and the skateboard move down the sidewalk with a speed of 4.25m/s. find the mass of the skateboard in units of kg. how fast would the student have ...
*January 22, 2012*

**physics**

a 43.7 kg student runs down the sidewalk and jumps with a horizontal speed of 4.48 m/s onto a stationary skateboard. the student and the skateboard move down the sidewalk with a speed of 4.25m/s. find the mass of the skateboard in units of kg. how fast would the student have ...
*January 22, 2012*

**physics**

a 43.7 kg student runs down the sidewalk and jumps with a horizontal speed of 4.48 m/s onto a stationary skateboard. the student and the skateboard move down the sidewalk with a speed of 4.25m/s. find the mass of the skateboard in units of kg. how fast would the student have ...
*January 22, 2012*

**Science help please**

My homework asks of me to write a sentence for each word reflecting the scientific meaning and showing how I understand what the word means. I am so puzzled and stuck. I have figured out the definition for the words, but I don't know how to write the sentences. The words ...
*September 25, 2011*

**psy 220**

Choose a public figure who has acted unwisely. Describe if it was a lack of emotional intelligence, successful intelligence, or both that caused his or her lack of judgment.
*July 11, 2011*

**math**

If you make a glass in the shape of a right circular cone (martini glass) how wide would the glass be if it is 4 inches tall and again holds 12 ounces?
*June 27, 2011*

**math**

How tall would a glass (in the shape of a right circular cylinder)with a diameter of 3 inches need to be to hold 12 ounces.
*June 27, 2011*

**math**

one fluid ounce of liquid is approx. 1.73 cubic inches so how many cubic inches are there in 12 ounces.
*June 27, 2011*

**principles of marketing**

what would be a good emotional advertising topic? I am having such a hard time trying to find something to write about please help me.
*May 28, 2011*

**emotinal advertising on life that have a marketing**

what is a good marketing focused emotional advertising on living
*May 28, 2011*

**pinciples of marketing**

what is a good emotinal advertising that could be used that would have a marketing focus
*May 28, 2011*

**Trigonometry**

You would start off by setting up the equation as follows: tan20=50/x (You would use tan because of the chief, SOHCAHTOA tan is opposite over adjacent. multiply by x on both sides leaving you with xtan20=50 Divide by tan 20. Your answer would be 137.37 meters
*May 18, 2011*

**math**

x=0 and -8 Set -x and x+8 equal to 0 and solve
*May 17, 2011*

**Trig/Pre-Calc**

The demand equation for a microwave oven is given by: p=500-0.5(e^0.004x) Find the demand x for a price of (a) p=$600 and (b) p=$300 Any help would be greatly appreciated.
*May 17, 2011*

**math**

Welcome
*May 17, 2011*

**math**

Yes, I'm sorry. That was a typo. It would be your width
*May 17, 2011*

**math**

You know that area of a rectangle is A=lw. If you know the area to be 15.86 square inches and the length to be 2.6 inches, you would set up the equation as follows and solve: A=lw 15.86=(2.6)(w) You would divide by 2.6 to get w by itself. You're length would be 6.1 inches...
*May 17, 2011*

**math**

You know the area of a triangle is A=1/2bh. So, to find how much larger the 2nd triangle is compared to the first, you would first find the area of the first triangle. Area of 1st triangle: A=1/2bh A=1/2(16.5)(8) A=66 feet Then find the area of the second triangle: A=1/2bh A=1...
*May 17, 2011*

**Chemistry**

To culinary experts and to the average person the term “Extra Virgin” has a ring of exclusiveness and quality to it. When it comes to olive oil, exactly what does this term signify? I am supposed to explain the chemistry behind Extra Virgin Olive oils, what makes the...
*March 29, 2011*

**chemistry**

To culinary experts and to the average person the term “Extra Virgin” has a ring of exclusiveness and quality to it. When it comes to olive oil, exactly what does this term signify? I am supposed to explain the chemistry behind Extra Virgin Olive oils, what makes the...
*March 28, 2011*

**chemistry**

What is the chemistry behind the “Breathalyzer” test. I'm supposed to explain the chemicals and structures involved with the reactions which produce the positive and negative results
*March 24, 2011*

**chemistry lab**

what contaminant will be the one that most affects the pH of soap?
*March 20, 2011*

**chemistry**

Why would you find ethanol or water during an aspirin lab?
*March 20, 2011*

**chemistry**

Why would you find ethanol or water during an aspirin lab?
*March 20, 2011*

**chemistry lab**

if you find salicylic acid or acetic anhydride in your aspirin synthesis product why are they there? Where did they come from?
*March 20, 2011*

**chemistry **

What is the principle source of Caffeine? I cannot find it at all!!
*March 10, 2011*

**chemistry **

What is the chemical structure, its principle source, its legals uses (if any) and its relative addictiveness on scale 1-10 : CAFFEINE
*March 8, 2011*

**statistical research**

Considering that a researcher can test at the <p = .05 (95%), p = .01 (99%), or p = .001 (99.9%) level for statistical significance, how do you use these three levels in relationship to evaluate risk to patients in implementing the decisions based on research findings?
*February 2, 2011*

**chemistry **

Draw the line structure for the compound: 2,5-dimethyl-3-hexane I believe the compound is C8H16...i am not sure!! :(
*January 30, 2011*

**chemistry **

Draw the line structure for the compound: 2,5-dimethyl-3-hexane I believe the compound is C8H16...i am not sure!! :(
*January 30, 2011*

**Calculus**

solve [1-cos(7pi/4)]/2
*January 24, 2011*

**chem help**

A sample of methane gas, CH4 was collected over water at 25 degrees celcius and 720 torr. The volume of the wet gas is 2.50L. What will be the volume of the dry methane at a standard pressure?
*November 30, 2010*

**chem help!**

An expandable balloon contains 1400L of He at .950atm pressure and 18 degrees Celcius. At an altitude of 22 miles (temperature of 2.0 degrees Celcius and pressure of 4.0 torr), what will be the volume of the balloon?
*November 30, 2010*

**math**

a rengular prism is made of 1-centimeter cubes. the volume of the rectangular prism i 60 cubic centimeters. which set of dimensionscould describe the rectangular prism?
*November 3, 2010*

**Chemistry**

If 10. g AgNO3 is available, what volume of 0.25M AgNO3 solution can be prepared?
*October 28, 2010*

**General**

Why don't my questions never get answered even after I post them several times.
*October 22, 2010*

**calculus**

i dont know
*September 29, 2010*

**calculus**

thanks
*September 19, 2010*

**calculus**

what normal annual interst rate has an effective annual yield of 7.8% under continuous compounding?
*September 19, 2010*

**calculus**

the second answer is 194.052 days
*September 16, 2010*

**Science**

It wasnt my hypothesis, though,. It was the one in the article.
*July 25, 2010*

**Science**

I was wondering the same thing...
*July 25, 2010*

**Science**

AI was wondering the same thing...
*July 25, 2010*

**Science**

Thanks for everything guys! This really helped! But I have another question related to my other question on here: Will the control be different, though, because the article says this: One one cup, she writes WATER, and fills the cup with water. On the next cup, she writes PURE...
*July 25, 2010*

**Science**

Please help me with my homework! OK, so there is this girl conducting an experiment to see whether a solution (juice) will take longer to freeze than a substance )pure water).She predicts that water will take less to freeze. So there is this article that goes on and on to list...
*July 25, 2010*

**math**

where does the 1.06 come from?
*January 27, 2010*

**math**

I think the answer is 1.2. 1. You simplify both sides: -1/2x = -3/5 2. Solve both sides separately: -0.5x = -0.6 3. And then you divide both sides: (-0.6 divide by -0.5]. 4. You get 1.2. I'm not sure if this is right :P Hope it is.
*May 8, 2009*

**math**

flip a coin 3 times a) what are the odds in favor of getting exactly 2 heads b) what are the odds against getting at most 1 tail
*October 31, 2008*

**A Tale of Two Cities**

wait, is this question u posted from 2008? why am i answering this question. its like 3 years later already!
*August 12, 2008*

**A Tale of Two Cities**

well read carefully and dont rush on getting a chapter done or u`ll not get it. read slowly and picture whats going on in the book. use sparknotes before you read so you get an idea of whats going on.
*August 12, 2008*

**Law and Ethics**

Wow you guys have been stuck on this for 3 months!? Are you kidding me!? I just started the book last week and I'm finishing it today. If you read the book, it gives you ALL the answers. Then go to AMA's website (as it says) and you can find most of the answers there ...
*July 20, 2008*

**chem**

name the following compounds and tell what type of compound they are (binary ionic. ternary ionic, or binary molecular) a)FeBr3 b)CBr4 c)Na2Cr2O7
*March 9, 2008*

**pre algebra 2**

you hate mr.chesley right?
*December 17, 2007*