# Posts by rina

Total # Posts: 73

**Chemistry **

The lab we are doing is: Determining the ENTHALPY of a Chemical Reaction. There are three reactions. Reaction 1: NaOH + HCl, Reaction 2: NaOH + NH4Cl, and Reaction 3: HCl + NH3. I found the max temp, initial temp, and temp change of each reaction. Can you help me with Reaction...

**math**

the ships leaves a port with a constant course and constant speed. after 2 hours the ship is 55miles south and 20 miles west of port. what is its course and speed?

**Algebra**

Four years ago, twice Athena's age was five less than her cousin's age. At present, the age of Athena's cousin is 18 years less than thrice Athena's age. What are their ages now? If Athena's age 4 years ago is x, then her cousin's age 4 years ago is ...

**science**

how Avogadros hypothesis applied to show molecular mass of volatile substances is twice of Vapour density?

**algebra**

Equation editor is function within blackboard. It allows students to do step by step math problems with equations rather than using the ^2 functions like they would on a calculator. If you see that, all it means is they're probably in an online class or their homework is ...

**History**

What was so significant about the space race? and why is it still significant and important currently today as of 2016?

**Math**

Six friends share 4 apples equally. How much Apple does each friend get?

**Physics**

A 12-V automobile storage battery has an internal resistance of 0.004 ohms. A) Find the current and power dissipation when the terminals are connected by a conductor of negligible Resistance B) The battery delivers 80A to the starter motor. What resistance would draw the same...

**Maths**

4 darts are thrown at the target. If each dart hits the target, How many different point totals are possible?

**Chemistry HELP**

Use the equation lamba=planck's constant/(mass)(velocity) Answer comes out to be: 6.06*10^6 m/s

**Physics**

A 250kg box is pushed horizontally with a force of 750 Newtons. If the coefficient of friction is 0.25, calculate the net acceleration of the crate. I am confused how I am to find the net acceleration. I solved to find FN and FG is 2452 N is that correct

**Physics**

spiderman is racing from the rooftop to catch the green goblin. he runs 125 m off a building 125 m tall to catch a robber coming out of the bank across thenstreet (30.0m away) if he is running at 10.0m/s will he hit the building, land the robber, or hit the ground before ...

**Chemistry**

Consider the titration of 100.0 mL of 0.260 M propanoic acid (Ka = 1.3 ✕ 10−5) with 0.130 M NaOH. Calculate the pH of the resulting solution after each of the following volumes of NaOH has been added. (Assume that all solutions are at 25°C.) (a) 0....

**chemistry**

Ok so I was making it harder than I thought and should have followed my instinct when my brain kept saying limiting reactant. Im gonna get it done then, last problem on homework. Thank You Dr. Bob

**chemistry**

sorry, I get distracted easily: Consider the reaction between 60.0 mL of liquid ethanol (C2H5OH; density = 0.789 g/mL) and 28.0 L of O2 at 27.0°C and a pressure of 1.51 atm. The products of the reaction are CO2(g) and H2O(g). Calculate the number of moles of H2O formed if ...

**chemistry**

Consider the reaction between 60.0 mL of liquid ethanol (C2H5OH; density = 0.789 g/mL) and 28.0 L of O2 at 27.0°C and a pressure of 1.51 atm? I am unsure of where to start with this problem...

**Diff Eq**

Consider a body moving along a straight line, in the presence of an external force providing constant acceleration a. In the absence of other forces, the velocity v of the body would increase without bound if a 6= 0. But in reality, there will always be a decelerating force, ...

**Math! Please help! anyone!**

Sorry. It's because it's a new semester and I got 6 homeworks to finish. I guess I was being a little impatient.

**Math! Please help! anyone!**

Please help me on my previous question for math! I really need help!

**Math**

Nevermind, because 9 8s bigger than 3 of course so it round down to 90 cents.

**Math**

yes, that is right! Because I kept rereading my math book and i found out it says to round off to the nearest ten cents. Thank You DrBob222!

**Math**

72.927 kw-hr. Am I right DrBob222? but do I have to round off 72.927 to the nearest cents?

**Math**

Find the cost of 999 kw-hr at 7.3 cents per kw-hr.

**math**

20/21 is your answer

**math**

alkdjflkajd

**Medical Biology**

Which of the following condition could result from years of smoking? a) tuberculosis b) emphysema c) empyema d) atelectasis

**Math**

Sam Quaker receives a salary of $300 per week plus a 5 and 1/2% commission on his sales. Last week he sold $3,880 worth of merchandise. How much did Mr. Quaker make last week?

**MATH! HELP!**

I got 634.10! I really got it wrong! But I'm still correcting it.

**NMR Organic Chemistry multiple choice**

I would say C. Heptanedioic acid is a chiral molecule. Please let me know if its right.

**math**

Jasmine has 8 packs of candle wax to make scented candles. Each pack contains 14 ounces of wax. Jasmine uses 7 ounces of wax to make one candle. How many candles can she make?

**AP Chem**

Complete and balance the following equations and identify oxidizing and reducing agents. S+HNO3---->H2SO3+N2O

**Trig**

The length of the base of an isosceles triangle is one fourth the length of one of its legs. If the perimeter of the triangle is 16 inches, what is the length of the base?

**College Algebra**

How would I go about solving for x in the equation: ln(4x-2)-ln(4)=-ln(x-2) Thanks in advance

**Math**

Marissa is 12 which means the younger bro is 9

**Trig**

Rewrite 7pi/5 in degrees.

**English**

Does everybody have a dark side? I need to write 4 paragraphs and I don't know how to start.

**Trigonometry**

8pi/17

**Trigonometry**

Find the supplement of 8pi/17.

**Calculus**

A certain calculus student hit Mrs. Evans in the head with a snowball. If the snowball is melting at the rate of 10 cubic feet per minute, at what rate is the radius of the snowball changing when the snowball is 1 foot in radius?

**math**

obesity is defined as a body mass index of 30kg/m2 or more. A 95% confidence interval for the percentage of U.S. adults aged 20 years and over who were obesity was found to be 22.4 to 23.5%. What was the sample size???? Can you please show your work?? Thanks

**Word Problems**

If your car gets 18 miles per gallon of gasoline, how many pints of gas will you need to take a 698- mile trip? I no that 1pt = 480ml and 1g= 3840 ml so do I x 18 miles per gallon by the amount of pints in a gallon?

**Math for pharmacy Tech**

My daughter Kim teaches and notes that the average student uses 75 sheets of paper every week. A) How many sheets will a student use in a 42-week school year? B) How many sheets will a class of 26 students use in a week? Not sure how to approach the problem. Do I first ...

**Perform the indicated operations**

X I I I x I V 10 1 1 1 x 1-5= 4 right above i have what each numerical # represents but i don't no if that's correct so far. How do i solve this?

**Converting Roman numerals to arabic Numbers**

Oh ok I got it now thank you so much

**Converting Roman numerals to arabic Numbers**

How does IX equal 9? I thought X represented 10 and I represented 1?

**Converting Roman numerals to arabic Numbers**

1) CCXIX C = 100 X = 10 I = 1 because there are 2 C's I added them together and I got 200 because there are 2 X's I added them together and got 20 because there is 1 I that equaled 1 So I added 200 + 20 + 1 = 221 which is my final answer But according to the back of ...

**Adding Fractions**

1) 2/3 + 1/8 = 19/24 I do not understand how they got 19/24 can you help me with the steps to show me how. Thank you

**Dividing Decimals**

I need Help with solving these problems. If you could show me the steps I think I will be able to get it. 1) 0.87/0.2 = 4.35 2)4.4/0.3 = 14.66 3)5.0/5.5 = 0.90 I got the answer by Calculator but when I do it myself I don't see how they got the answer. Please help. Thanks

**math**

You can break up 9 to 3 x 3. Then you have 3 x 3 x 3= 27 I don't know how much easier that makes it, but I guess you could do it that way. The smaller the numbers you're working with, the smaller the chance you'll mess up.

**STATS**

Samples of both surface soil and subsoil were taken from eight randomly selected farms in a county. The soil samples were analyzed to determine both surface pH and subsoil pH, which yielded the following results: Farm 1 2 3 4 Surface pH: 6.55 5.98 5.59 6.17 Subsoil pH: 6.78 6....

**Statistics**

A sociologist is testing the null hypothesis that the percentage of school superintendents who earn an annual salary of more than $150,000 is greater than or equal to 50%. The sociologist conducts a poll of 1100 randomly selected superintendents and finds that 565 earn more ...

**Biology**

Ok thank you I think that might will help

**psychology**

lol yes I am confused genetics is not my subject although I love psychology I can do without the gentics portion. But thank you so much for bring patient with me in my quest for the answer

**psychology**

Ok I think I got it now if I am not right this time am just going to have to get this one wrong lol. So I re-read my book and I believe that the answer is D now because the book states the following: "Gentic explanations, however, have a fatal flaw. They use heritability ...

**psychology**

Within groups, differences in intelligence are highly correlated with_______. Between groups, differences are highly correlated with ________. a) heritability: environment b)environment: genes c) heritability:random error in measurment d) genes: the heritability estimate my ...

**Psychology**

Ok now am confused, if its not A or B then is it C? because the book states the following "although intellectual differences within groups are at least partly genetic in orgin, that does not mean differences between groups are genetic.

**Genes**

Genetics and what we inherit from our biological parents play a significant role in our intelligence level. In fact, researcher have found that: a) adotpted children are more similar in IQ to their adoptive parents than to their birth parents b) identical twins raised apart ...

**psychology**

Peter and Maria are adopting a child whose biological parents have low IQs. They want to know if this child, too is likely to have a low IQ? Which one of the following is the best response to their question? a) While IQ is heritable at least in part, environmental influence ...

**psychology**

sara overhears her 21 year old son, joe, telling his friends on the phone that he wants to have sex with two girls he just met at the mall. joe's desire: a) expresses the male tendency to commit to a relationship b) is an example of male nurturance c)expresses the male ...

**psychology**

evolution has installed tendencies in our selection of a mate. Two of the strongest predictors in human mate selection today are: a) wealth and attractive b) attractiveness and youth c) similarity and proximity d) the best genetics and submission i chose A but i think this is ...

**psychology**

lol i guess i was because i was thinking in terms of now how things are and how technology is taking over as far as learning

**psychology**

Parents can help their children acquire language by: a) reading and talking with them b) correcting every grammatical mistake c)placing them in front of a computer d) eating foods rich in vitamin A Am confused between b and c but i am leaning more towards c

**Psychology**

i got it now i did go back and re read it and i believe it is B) A natural inclination, because they relate to language Thank you so much sometimes the answer is really right in front of your face :)

**Psychology**

I agree math in it self is its own language but the question is, is it present in us from birth or are we born with it and need to be challenged in order for it to develop effectively?

**Psychology**

Basic arthmetic is not an easy task for Jeanne. In fact, she has to work hard at understanding mathematical concepts. She finds it hard to believe that basic math skills are: A) present in all species B) A natural inclination, because they relate to language C) Present in all ...

**science**

what does liver do

**CULTURAL DIVERSITY**

hey um i cant find anything on how cultural diversity occurs i wish someone would out it out there this is for a grade and i cont affrod another frakin zero. this looks like a good site so plz put hoe cultural diversity happens for goodness sakes. i don't want to have to ...

**3rd grade math**

bob is the catcher

**Speech**

Well i just started this topic and I viewed Al Gore's presentation on global warming.I thought it had some good ideas. Thanks

**Speech**

I have to give a problem-solution speech on "Global Warming" what would i put into this? I need to point out some good solutions to the problem. It has to be a really interesting speech for the audience any pointers would be good. I also need a power point to go ...

**Calculus**

Thanks. Actually i did not learn that other rule yet and I don't think we will but thanks anyway it was helpful. I solved using bobpursley's idea and got sqrt2/2=1/sqrt2.

**reading**

I need a summary for the following report.Antisemitism (alternatively spelled anti-semitism or anti-Semitism; also rarely known as judeophobia) is prejudice against or hostility toward Jews as a group. The prejudice or hostility is usually characterized by a combination of ...

**math**

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