Monday

January 26, 2015

January 26, 2015

Total # Posts: 2,384

**Physics**

Subject: Light and Geometric Optics Question: Where must a light source be placed in front of a concave mirror for a) light energy to be concentrated to a single point b)the light to be reflected in a parallel beam?
*May 22, 2010*

**Honors Chemistry**

Thanks so much!! This helped a lot!! :)
*May 20, 2010*

**Honors Chemistry**

"Would it be possible to have an addition polymer synthesized from a monomer that has only single bonds? Why or why not?" ==> I know that an addition polymer can only be synthesized from a monomer that has double bonds, but my textbook did not explain why. Can ...
*May 20, 2010*

**geometry**

The measures of the angles in quadrilaterals are in the extended ratio of 3:4:5:6. What are the measures of the angles?
*May 19, 2010*

**math**

how to solve y= 3cos2x + 5 pls help me
*May 18, 2010*

**Chemistry**

I know this is supposed to be a really easy concept, but I need help with balancing redox reactions: KClO3 ==> KCl + O2 My textbook says to write the ionic equation next, which I have written like: K(+1) + ClO3(-1) ==> K(+1) + Cl(-1) + O2(-2) (the number in parentheses ...
*May 17, 2010*

**Chemistry**

An air bubble has a volume of 0.500 L at 26 Celsius. If the pressure does not change, what is the volume, in liters, at -14 Celsius? If the pressure does not change, what is the volume, in liters, at 600 k?
*May 17, 2010*

**Math Analysis**

Use the half-angle formula to find the exact value of cos(x/2) when tanx = -5/8 and x is in quadrant IV. (| is a radical) ==> I got sqrt((89 + 8sqrt(89))/178). Is this correct? I hope my answer is easy to read..
*May 3, 2010*

**math analysis**

There's a hidden trigonometric identity.... 2sinxcosx ==> 4sinxcosx = 1 2(2sinxcosx) = 1 2sin2x = 1 Then you solve for x :)
*May 3, 2010*

**Math Analysis**

Oops, yeah those were supposed to be radicals :) thanks so much!!!!
*May 3, 2010*

**Math Analysis**

Find the exact value of cos(x/2) if sin x = 3/4 and x is in quadrant II. ==> I got ã(4-ã7)/2. Is this correct?
*May 3, 2010*

**Physics**

thanks!
*May 3, 2010*

**Physics**

Which is more harmful---smaller wavelength, like gamma ray, or larger wavelength, like radio waves?
*May 3, 2010*

**Physics**

thanks!
*May 2, 2010*

**Physics**

What is a mirror ( reflective surface and back) made out of?
*May 2, 2010*

**Phsyics**

Can you explain to me how an LCD works?
*May 1, 2010*

**Physics**

Thanks you!
*May 1, 2010*

**Physics**

What gases are in a fluorescent and incandescent bulb?
*May 1, 2010*

**Physics**

How when light rays travel outward from their light source in all directions, they are not parallel to each other, but when they approach an object they are parallel to each other?
*May 1, 2010*

**Physics**

DO diffuse reflections still follow the law of reflection? (Angle of incidence equals angle of reflection)?
*May 1, 2010*

**us history**

Do you think the changes in the 1920s gave Americans more control over their lives? Explain
*April 29, 2010*

**Physics**

How do you see your reflection in a plane mirror?
*April 29, 2010*

**Calculus**

Find the absolute max of f(x)=5x-e^(5x)
*April 28, 2010*

**Physics**

Does the law of reflection only apply to mirrors or any object?
*April 28, 2010*

**Honors Chemistry**

Ohhhh I see now! Thanks so much!! :)
*April 27, 2010*

**Honors Chemistry**

That's supposed to be q = mc(delta)T
*April 27, 2010*

**Honors Chemistry**

I have two questions on my review study guide that go like this: 1) What is the equation for calculating the energy change that occurs when a substance changes state? 2) What is the equation for calculating the energy change that occurs when a substance increases in ...
*April 27, 2010*

**Physics**

A balloon appears to be yellow when seen in white light. Explain the colour it will appear in a) green light and b) magenta light. I really don't undestand the subtractive theory of light, and it applies to this question. Can you plese explain to me how to get the answer? ...
*April 25, 2010*

**chemistry**

when 5.0 g of CaCl2 is dissolved in 50 g of water, how do you get the boiling temperature of 101.5 degree c
*April 22, 2010*

**Math**

Idk . how to even do ?
*April 20, 2010*

**Math**

The Relatioship between x and y is y=5x + 18 How does the value of y change when x increses form 1 to 4? a. y increase by 15 b. y increase by 3 c. y decresases by 3 d y dercreased by 15 Help Prettty Pleassseee !
*April 20, 2010*

**geometry**

write an expression for the sum of the angle measures in a regular polygan with n sides. then wirte an expression for the measure of each angle in a regular polygan with n sides.
*April 19, 2010*

**Chemistry**

Why is it not a good idea to use an antacid routinely? (two reasons)
*April 18, 2010*

**Chemistry**

How come the charges of H*2O*2 (asterisk means subscript), which is hydrogen peroxide,don't equal? The charge of hydrogen is 2, and the charge of O is 4. For an ionic compound you can figure out the formula by the charges(when the charges of the ions add up to zero) but ...
*April 17, 2010*

**S.S**

Could you drive from Wisconsin to Michigan without crossing another state? If yes, how? If no, why not?
*April 17, 2010*

**Social Studies**

What is the name of the only colony on the South American continent?
*April 17, 2010*

**Chemistry**

If you have to write the products of the chemical reaction Fe+O*2( asterisk means subscript),how would you know the charge of Fe in the compound FeO? If the charge is 2+, then the product would be FeO, but if the charge was 3+, then the product would be Fe*2O*3. Thanks!
*April 17, 2010*

**Chemistry**

Suppose you place a kettle on the stove and boil some water.Is the steam that forms physical of chemical change?
*April 16, 2010*

**math**

what is the perimeter of a rectangle that measures 27 inches on one side and 56 inches on the other side?
*April 14, 2010*

**business law**

Please give me some insight on a law hypo...? This is the hypo: Joe received an advertising brochure from X Corp. in the mail. The brochure contained a photo of a Peach 442 computer, and above it the statement, "While supplies last. All Peach computers on sale at 25% ...
*April 14, 2010*

**Physics**

i figured it out after all - thanks
*April 13, 2010*

**Physics**

The work function for potassium is 2.24eV. If potassium metal is illuminated with light of wavelength 310 nm, find the maximum kinetic energy of the photoelectrons. I have tried everything and still keep getting the wrong answer. The speed of light is 3 × 108 and Planck...
*April 13, 2010*

**fraction comparisons**

Max did 19 situps. This is 1/7 as many as Isabel. How many situps did Isabel do?
*April 12, 2010*

**chemistry**

help me. i dont understand
*April 11, 2010*

**chemistry**

Excess florine, F2(g) reacts at 150 degrees celius with bromine, Br2(g) to give the compound BrF(n). If 423 mL of Br2 at 150 Degrees and 748mmHg produced $.20 g BrF(n), what is it? describe the bonding in the molecule, using valence bond theory.
*April 8, 2010*

**grammer**

Yesy the correct one is 3. The conjunction in that sentence is for. A conjunction links sentences together. There is always a comma before a conjunction.
*April 8, 2010*

**geometry**

y= 24
*April 8, 2010*

**MATH**

It is a well-known fact that homing pigeons fly faster over land than over water. Assume that they fly at 10 metres per second over land, and only 8 metres per second over water. A pigeon is located at the edge of a straight river bank, 500 metres wide, and must fly to its ...
*April 8, 2010*

**geometry**

If a circle has a diameter of 2 3/8 inches, then what is the length of the radius?
*April 5, 2010*

**algebra **

Find the minimum and maximum values of the objective function subject to the given constraints? Objective Function: C=4x+5y Constraints: x>=0, y>=0, x+y<=6
*April 4, 2010*

**math**

you work at a grocery store. your hourly wage is greater after 6pm than it is during the day. one week you work 20 daytime hours and 12 evening hours and earn $280. another week you work 30 daytime hours and 12 evening hours and earn a total of %276. what is your daytime rate...
*April 2, 2010*

**math**

during a recent telethon people pledged $25 or $50. twice as many people pledged $25 as $50. altogether, $18000 was pledged. how many people pledged $25?
*April 2, 2010*

**Help me think of ideas for my essay?**

My thesis statement for my synthesis essay to connect The Grapes of Wrath, The Great Gatsby and The Death of a Salesman is "It is impossible to maintain honor and also achieve success." Could anybody give me any ideas for my 3 body paragraphs I'm having trouble ...
*April 1, 2010*

**Chemisty**

calculate pH of 50.0 mL of a .100 M solution of the weak monoprotic acid HX
*March 29, 2010*

**Chemistry**

When you balance equations, do you treat polyatomic ions as one unit or treat the different elements in the ion separately? Because if you treat them as one unit, then what if the elements get separated in the products side of the equation?
*March 27, 2010*

**Physics**

i need help on this problem too
*March 26, 2010*

**9th grade**

soil dwelling insects are examples of invertabrates. explain why this statement is true and use examples of two soil dwelling insects
*March 23, 2010*

**Civics**

Are there any reliable websites that would give information and statistics on improvements that should be made to Immigration Canada?
*March 21, 2010*

**science**

I am doing a project on the Silurian time period and we need to know some organisms that were created during the time and some that went extinct. I found a bunch that were created but i didnt find any that went extinct!! Help!!
*March 16, 2010*

**math**

5 x (x + 2y) - (5x +2y) + y(2x + z) translate into a word phase.
*March 12, 2010*

**physics**

A 250. MW coal-fired power plant burns fuel with an energy density of 35.0 MJ kg-1. Water enters the temp reduction tower at 293 K and leaves at 350. K at a rate of 4200. kg s-1. 4. Calculate the energy removed by the water each second. 5. Calculate the energy produced by the ...
*March 11, 2010*

**4gr math**

6/87
*March 7, 2010*

**4th grade math**

write and solve a mixed number word problem
*March 4, 2010*

**fractions **

Claire cut some apples into eights. She ate all but 17 pieces. how many whole apples and parts of apples did she have left over?
*March 3, 2010*

**fractions**

Castor brought 6 3/4 cakes to share with 26 students. Did Castor bring enough for each student to have 1/4 of a cake? Explain your thinking and show your work
*March 2, 2010*

**Math Analysis**

From a ship off-shore, the angle of elevation of a hill is 1.1°. After the ship moves inland at 4.5 knots for 20 min, the angle of elevation is 1.4°. How high is the hill? (1 knot = 1 nautical mile = 6080 ft per hour) As I was just about to get the answer, I realized ...
*March 2, 2010*

**4th grade**

4/5682
*March 1, 2010*

**science**

I figured out the other three questions but im stuck on this one... If you digest an entire human genome with a restriction enzyme you get a blurry smear in the lane of the gel. Why?
*March 1, 2010*

**science**

What type of organism makes restriction enzymes? How did restriction enzymes evolve? How do scientists use restriction enzymes? If you digest an entire human genome with a restriction enzyme you get a blurry smear in the lane of the gel. Why? I have a quiz tomorrow on ...
*March 1, 2010*

**6th grade**

Cone u
*February 24, 2010*

**english**

"There" is defined as "at or in that place." ex. Sit over there. "They're" is a contraction of the two words "they are." ex. They're sitting on the bench. "Their" is the "possessive form of 'they'." ex...
*February 23, 2010*

**Honors Chemistry**

How does heating or boiling a substance affect its pH?
*February 23, 2010*

**pre calc**

You're correct about the numerator. You would simplify the denominator to be x(x-1). So now you have: x(x+2) ------- x(x-1) You can cancel out the x's on both the numerator and denominator, and so for your final answer you would have: (x+2) ------ (x-1) Does this make ...
*February 23, 2010*

**Algebra 2**

Both the numerator and denominator have the same bases for the exponents, right? So, dividing these two variables is the same as subtracting the exponents, like: n^(3-¨i)
*February 23, 2010*

**Honors Chemistry**

Ohhh I see. This makes more sense. Thank you! :)
*February 23, 2010*

**Honors Chemistry**

If 20 mL of 0.01 M aqueous HCl is required to neutralize 30 mL of an aqueous solution of NaOH, determine the molarity of the NaOH solution. ==> I got 0.01 M NaOH as my answer. Is this correct?
*February 23, 2010*

**Honors Chemistry**

I don't exactly understand this question -- can someone maybe explain it to me please? 6) Suppose you have an NaOH solution of unknown concentration. Name three possible substances that could be used in "known" solutions to titrate the NaOH solutions.
*February 23, 2010*

**Math**

In right triangle ABC, altitude CD is drawn to hypotenuse AB. If AD equals 4 and AC exceeds DB by 1, find DB. It is from a worksheet about proportions in a right triangle.
*February 21, 2010*

**pre-Algebra**

Sorry, struggling through pre-Algebra .. :-( .. How do i figure out 5x = -20 ?
*February 19, 2010*

**Pre-Algebra ... again :-(**

Thank you Miss Rose!
*February 19, 2010*

**Pre-Algebra ... again :-(**

How do i go about finding the integers of a product and quotient ... like, product of -20 whose quotient is -5 ..... thanks again
*February 19, 2010*

**Math Pre-Algebra**

Gotcha ... makes sense to me! :-) ... thank you! ... i may be back! :-)
*February 19, 2010*

**Math Pre-Algebra**

What is the value of 1 raised to a negative exponent? ... Maybe an example would help me better understand. Thank you very much ... I know it is like a fraction
*February 19, 2010*

**Data management**

The camera club has 5 members, and the math club has 8 members. There is only one member common to both clubs. In how many ways could a committee of 4 people be formed with at least 1 member from each group?
*February 17, 2010*

**chemistry**

is the correct answer 68.93kJ?
*February 16, 2010*

**chemistry**

Given that the specific heat capacities of ice and steam are 2.06 J/g°C and 2.03 J/g°C, the molar heats of fusion and vaporization for water are 6.02 kJ/mol and 40.6 kJ/mol, respectively, and the specific heat capacity of water is 4.18 J/g°C, calculate the total ...
*February 16, 2010*

**chemistry**

What quantity of heat is required to vaporize 32.5 g of liquid water at 100°C?
*February 16, 2010*

**Ecology**

How does the skin and life cycle of a frog help indicate the health of local ecosystems?
*February 13, 2010*

**cal 2**

Find the number b such that the line y = b divides the region bounded by the curves y = x2 and y = 16 into two regions with equal area. (Round your answer to the nearest hundredth.)
*February 12, 2010*

**Science**

Plants, cows and humans use the same amino acids to make up their proteins and yet the proteins are very different. Why?? Could a plant make a human protein if we could splice a human protein gene into the plant's genome? Why? ----Those questions are from a lab we did, i ...
*February 11, 2010*

**English**

We are doing this group project where we have to teach the class our vocab words. My job for the project is to make big flashcards with pictures of the words on it. One of the words is vignette, and I have no idea what picture to use, the definition is short verbal description...
*February 10, 2010*

**gr. 10 physics **

I must find the speed of an object, the infermation that is given to me is:n height: 0.10 kinetic energy: 0.50 time travel o.72 (m/s squared). i belive that speed = 0.3... is this correct?
*February 9, 2010*

**Yr 10 English - Poetry**

What were the hobbies (if any) of Nobel Prize winning poet Seamus Heaney? I searched everywhere and couldn't find anything. . .
*February 8, 2010*

**algebra**

x - = 12 3
*February 3, 2010*

**English- Mrs.Sue Please**

Hello Im am stuck on these sentence things and we have to say if it is a preposition, verb, pronoun, conjunction ect. what do I do?
*February 1, 2010*

**Spanish **

how do you make comparisions use equality and superlatives?
*January 26, 2010*

**CP Science 9th grade**

A Sample of Air at 35 degrees Celsius has a relative humidity of 15%. How do you find the dew point temperature?
*January 26, 2010*

**FIN200- FV, PV and Annuity Due CP**

Take the $95. Assuming you take the $95 and compound it daily at an annual rate of 12% for 50 years you would have $38,287.96 which is obviously more than $30,000.
*January 26, 2010*

**Literary Analysis and Composition**

Hey, I was trying to figure out some similarities between the Stories Barrio Boy by Ernesto Galarza and No Gumption by Russell Baker. I got some, but I am supposed to make a four paragraph essay out of it. It would be great if you could list some similarities and differences. ...
*January 22, 2010*

**Literary Analysis and Composition**

thanks! i got a B+ (88.2%)
*January 21, 2010*

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