Thursday

March 5, 2015

March 5, 2015

Total # Posts: 140

**5th grade science**

It might be just a portion of the water cycle - evaporation - since it only mentions water going up.
*May 12, 2009*

**Math**

Start with the relation beween cm and dm. 1 dm = 10 cm Now figure out the relationship between CUBIC dm and CUBIC cm. 1 cubic dm = 1 dm * 1 dm * 1 dm 1 dm * 1 dm * 1 dm = 10cm * 10cm * 10cm so 1 cubic dm = 1000 cubic cm See if you can take it from there.
*May 12, 2009*

**CHemistry**

Does the second question mean, "B. Which of the following molecules are likely to form hydrogen bonds [with themselves]?" You can get different answers depending on whether or not that added part is implied.
*May 12, 2009*

**Science**

Angie, yes, summer and winter are "reversed" in Antarctica. Gabriel, you should post your own question instead of piggy backing on someone else's. And atoms are not the smallest particles: atoms consist of subatomic particles called protons, neutrons, and ...
*May 12, 2009*

**physical science**

The majority of volcanoes form near plate boundaries. A good example is the so-called "ring of fire" encircling most of the Pacific Ocean. However, the chain of islands of Hawaii are volcanic but are nowhere near a plate boundary. They arose from a mantle plume - a ...
*May 12, 2009*

**science**

Karyotypes are pictures of a cell's chromosomes taken when they are the most visible (most condensed). The picture is then edited so that all of the chromosomes are oriented in the same direction, paired up, and then sorted into the correct numerical order. A karyotype can...
*May 12, 2009*

**MATH**

solve the first equation for either variable. For example, solve it for x. x + y = -4 x = -y - 4 Then, where ever that variable appears in the second equation, replace it with the value from the first equation that is equal to it. This will allow you to find the value of the ...
*May 12, 2009*

**math**

Actually, there's a more general way. 1) Is the "state" one of the first 3 elements in the set? Yes {Montana, Washington, Idaho} No {Oregon, Alaska, British Columbia, Alberta}. Suppose the answer is no. 2) Is the "State" one of the first 2 elements in ...
*May 12, 2009*

**math**

You could do the same general thing as Count Iblis suggested but instead of finding the populations, you can use letters in the names of the "States". I will show one possible path (note that the way you phrased the question, you can ask a different set of questions ...
*May 12, 2009*

**Math**

1) Solve the first equation for either variable. 2) Every where in the second equation that the solved-for variable appears, replace it with the value it is equal to. 3) You now have only 1 variable in the second equation. Solve the second equation for that variable and you ...
*May 12, 2009*

**MATH**

*********************** x^4-2x^2+1=0 I dont think you can factor that unless its (x^2+1)(x^2-1) *********************** If you FOIL that, you will get x^4 - 1, not x^4 - 2x^2 + 1. You can factor by grouping x^4 - 2x^2 + 1 = 0 x^4 - (x^2 + x^2) + 1 = 0 x^4 - x^2 - x^2 + 1 = 0 x...
*May 12, 2009*

**algebra**

The only "tricky" part is which part you do before the other: the subtraction [5 - 3](1-2x) or the diistribution 5 - [3(1-2x)]. If you remember your order of operations you can figure that out: which has a higher priority, subtraction or multiplication?
*May 12, 2009*

**math**

The only "ticky" part is the negative outside of parentheses. Just convert the negative sign into the implied + -1 and then distribute it. 2 - (x + 4) = x - 3 2 + -1(x + 4) = x - 3 2 - x - 4 = x - 3 You should be able to finish it.
*May 12, 2009*

**science**

Contraction
*May 11, 2009*

**6th grade**

But, if you feel you need to show the addition step, then you could do something like this (the vertical addition will probably not line up here) 2.3 + 4.09 = N 2.3 + 4.09 ------ 6.39 6.39 = N
*May 10, 2009*

**6th grade**

For simple addition of two terms, it is usually fine to just show the result. For example: 2.3 + 4.09 = N 6.39 = N (And if you want, change the sides so that N is on the left)
*May 10, 2009*

**Math**

Have you figured out the pattern?
*May 10, 2009*

**Algebra**

1) Do you mean what is the square root of 7/10? 2) What process did you use? It look like you just subtracted 4 from the numerator and the denominator and put the four outside.
*May 10, 2009*

**Math**

Remember that "percent" means "per hundred". So 94.6% means 94.6 per hundred, which is the same as 94.6 ----- 100 Either use a calculator or move the decimal point 2 places to the left in the numerator. Either way, you get 0.946. Reading the decimal, we get...
*May 10, 2009*

**math**

It is not that there is NO y value, but that there are an INFINITE number of y values.
*May 10, 2009*

**science**

And if you are allowed to define something by including in the definition what it is not, then for an amphibian I'd define it as amphibian: a non-amniote tetrapod.
*May 10, 2009*

**science**

FYI: For fish, from the linked-to site, use 2 of the defintions: ********************************* 1. Any of numerous cold-blooded aquatic vertebrates of the superclass Pisces, characteristically having fins, gills, and a streamlined body and including specifically: a. Any of ...
*May 10, 2009*

**Math**

Because homeruns aren't hit when pigs swim through molasses.
*May 10, 2009*

**math**

Remove the parentheses. For the second set of parentheses, consider the - in front of it to be + -1 and distribute the -1 across all terms within that set of parentheses. Rearrange terms so that they are in descending order. Combine like terms.
*May 10, 2009*

**science**

temperature high It's common sense that evaporation of water occurs at high temperature more readily than at low temperature. humidity low The less water vapor already in the air, the easier it is to introduce water vapor into the air. wind high Wind helps remove water ...
*May 9, 2009*

**science**

Another possibility (can't tell exactly what the question is asking) is that a bird, in science terms but not everday terms, is a reptile. The newer classifications attempt to be monophyletic, so the term reptile includes all reptiles and all animals descended from ...
*May 9, 2009*

**Math**

There is no general method to do this other than pure trial and error. So try different positions for the parentheses until it works.
*May 9, 2009*

**physics**

Nat, use what Count Iblis provided. PS: drwls, the question asks about the momentum of a proton, not a photon.
*May 9, 2009*

**10th grade Living Environment**

Yes, it is a test cross.
*May 8, 2009*

**PreAlgebra**

Your method should work. area = 2 * pi * radius^2 area ~ 6.28 * radius^2 POND: diameter = 20m radius = diameter / 2 radius = 20m / 2 = 10m area = 6.28 * (10m)^2 = 6.28 * 100m^2 area = 628m^2 POND and WALK: remember, the walk goes all the way around the pond, so there is 5m of ...
*May 8, 2009*

**Biology**

And here are some important experiments that relate to the RNA World (to differing degrees). 1. RNA 20-50 mers were produced using a 10 mer primer on montmorillonite 2. Multiple classes of ribozyme ligases were isolated from a pool of 10^15 **RANDOM** 220 mers 3. Scientists &#...
*May 8, 2009*

**Biology**

Abiotically (that is, non-biologically) produced organic compounds important for RNA World 1. Purines (xanthine, hypoxanthine, guanine, and adenine) were present in the Murchison meteorite 2. The pyrimidine uracil was present in the Murchison meteorite 3. The pyrimidines ...
*May 8, 2009*

**Biology**

Some biochemical evidences that there was once an RNA World... 1. The RNA World solves the chicken-or-egg paradox, “Which came first, DNA or proteins?” The answer would be, neither: an RNA molecule capable of both storing genetic information and catalyzing its own ...
*May 8, 2009*

**Biology**

The origin of life (abiogenesis) is not understood anywhere near as well as evolution is, so no one can give you a really strong answer. There are several different theories for the OOL, one of which is the RNA World theory. Originally, it held that a specific type of RNA (a ...
*May 8, 2009*

**visual basic**

I just figured it out: It's simpler than that. You are declaring all of your numeric variables a LONG. LONG is an integer data type: it does not store anything to the right of a decimal point. Try using DOUBLE (or better, DECIMAL, if your version supports it) for any ...
*May 8, 2009*

**visual basic**

The problem MIGHT be here. result = ((A(Original)) / ((B(Desired)) / Feet)) Some languages (like C and C++) do integer division unless you explicitly make it do "normal" division. In other words, if you do 5/2 in C the result will be the integer 2, not the "...
*May 8, 2009*

**math**

The sum of the measures of the three interior angles of a triangle is 180 degrees. So: 2x + 3x - 15 + 7x + 15 = 180 12x = 180 x = 15 So the measures of the angles are 30, 30, and 120. That should be enough for you to answer the question.
*May 7, 2009*

**math**

Draw it out. Draw an equilateral triangle, then place an circle inside of it such that the circle just touches each side. Then draw another circle slightly larger than the first.
*May 7, 2009*

**math**

p = mgh Solve that for g using algebra. Since in mgh g is multiplied by m and h, do the opposite: divide mgh by m and h. And remember that what you do to one side of an equation you must do the other side as well.
*May 7, 2009*

**Living Environment**

How did Mendel allow a single garden pea plant to reproduce with itself?
*May 7, 2009*

**living environment**

Is that the exact language used in the original question? What are "two pieces of DNA"? Does it mean the two polynucleotide strands? But they are joined together (into a double helix) all the time, except for short segments at a time that separate during replication ...
*May 7, 2009*

**Pre-Algebra [repost]**

If you cannot learn the GENERAL PROCESS, then you need to be taught the same general thing a million different times. You need to learn how to abstract ideas and then apply them to specific instances.
*May 7, 2009*

**visual basic**

In VB, you should use OPTION EXPLICIT whenever possible in order to let the 'compiler' endorce strong typing.
*May 7, 2009*

**Pre-Algebra**

You've been shown how to solve these types of problems multiple times. It's like someone explains to you how to solve x + 1 = 5, but then you create another post because you don't know how to solve x + 1 = 6, and the another post because you don't know how to ...
*May 7, 2009*

**Physics**

Um, how can one determine a relativistically affected length, if no length at all is given in the problem?
*May 6, 2009*

**Math**

Get all of the terms to the left side by adding -3x and -4 to both sides. -x^2 - 3x - 4 = 0 divide through by -1 (divide each term by -1) x^2 + 3x + 4 = 0 factor the trinomial (x + 3)(x + 1) = 0 see if you can take it from there.
*May 6, 2009*

**Physics**

Choose a speed for which relativistic effects are negligible. Say, 0.001 c, which is 300 km/s. Solve the classical (p = mv) and the relativistic (p = 'gamma' mv)equations for momentum, using the value selected above for velocity. The results should be almost identical.
*May 6, 2009*

**math**

What exactly is Lucky Coin? What is the probability of winning given a single shot?
*May 6, 2009*

**math**

If I wanted to be sure to take out a blue block, I would put in only blue blocks.
*May 6, 2009*

**math**

Factor out the GCF of the 2 terms. x(x - 5) = 0 Can you take it from there?
*May 6, 2009*

**Algebra**

You did not split the middle term, you added a term "out of the blue". The numbers to use to split the middle term are 2 and 1. When multiplied together, they give 2 (that is the product of a and c), and when added together they give 3 (that is b). 2x^2 + (2x + 1x...
*May 6, 2009*

**Algebra 1**

w^2 + 15w - 12w - 180 = 0 pull out the GCF of each pair. w(w + 15) - 12(w + 15) = 0 then pull out the common factor (w + 15) from eatch term. (w + 15)(w - 12) = 0 see if you can take it from there.
*May 6, 2009*

**chemistry**

It will help if you start using the unit factor method. It shows up a lot. In it, you find an equation that links the units you have to the units you need. 1m = 100cm Since the two sides are equal, either one over the other will be equal to 1. 1m/100cm = 1 and 100cm/1m = 1 You...
*May 6, 2009*

**MATH!!!!!!**

But no work was shown. Was this just trial and error, or was math used? "the sum of two numbers is 99" x + y = 99 "the difference of those two numbers is 9." x - y = 9 Solve one equation for either variable. x - y = 9 x = y + 9 now substitute this value for...
*May 6, 2009*

**Physics**

In calculating the force of gravity between two objects, if the distance between the objects is increased 4 times, the force of gravity will (DECREASE BY 1/16) Actually, it will be decreased TO 1/16 of the original force. The way you stated it, the force would be decreased BY ...
*May 6, 2009*

**Pre-Algebra**

It would be easier if you solve the equations for y, then plug in a value for x. -3x - 2y = 0 add 3x to both sides -2y = 3x divide both sides by -2 y = (-3/2) x Now just pick numbers for x (because of the 2 in the denominator, it will help to pick even integers). x = 2 y = (-3...
*May 6, 2009*

**math**

Best I can come up with is: (py - by)/(px - bx) = -1 [(px - ax) / (py - ay)] It relates the slopes of two perpendicular lines: each line's slope is the negative reciprocal of the others. The problem arises when one of the slopes is 0, because then the (negative) reciprocal...
*May 5, 2009*

**math**

Best I can come up with is: (py - by)/(px - bx) = -1 [(px - ax) / (py - ay)] It relates the slopes of two perpendicular lines: each line's slope is the negative reciprocal of the others. The problem arises when one of the slopes is 0, because then the (negative) reciprocal...
*May 5, 2009*

**8th Grade Algebra**

(3t^2 - 2t - 4) * (5t + 9) Multiply each term in one set of parentheses by each term in the other set of parentheses. 3t^2(5t + 9) - 2t(5t + 9) - 4(5t + 9) 15t^3 + 27t^2 - 10t^2 - 18t - 20t - 36 combine like terms 15t^3 + (27t^2 - 10t^2) + (- 18t - 20t) - 36 15t^3 + 17t^2 -38t...
*May 5, 2009*

**Algebra**

3/8 (5 + 6x) + 3 > 21 Multiply through by 8 (multiply each term by 8) to eliminate fractions. 8[3/8 (5 + 6x)] + 8[3] > 8[21] 3(5 + 6x) + 24 > 168 distribute the 3 15 + 18x + 24 > 168 combine like terms 18x + 39 > 168 isolate the variable by subtracting 39 from ...
*May 5, 2009*

**7th grade**

You cannot solve the expression for x: it is not an equation (just an expression) and you cannot convert an expression into an equation. x can have any of an infinite number of values. All you can do is simplify the expression to either 5x - 5 or if you are working with ...
*May 5, 2009*

**Algebra**

Can you do the first part, of simplifying the inequality?
*May 5, 2009*

**science**

Which has more volume: a cup of x or a cup of y? Wouldn't they both have the same volume, since they are both a cup of something?
*May 5, 2009*

**Math**

Convert the words into one or more mathematical equations. I'll get you going on the first one. "The difference of two numbers ..." x - y "... is tripled." (x - y) * 3 or equivalently 3(x - y) "The result is decreased by 1." 3(x - y) - 1 "...
*May 5, 2009*

**MAth**

Your coordinates do not make a square. Fix your coordinates first, then see if taking the negative of each number works.
*May 5, 2009*

**Marine Science**

Many fish have a lateral line system that is invovled in their senses: I would guess that a bluefin tuna does too. You might want to Google "lateral line system".
*May 5, 2009*

**math**

The UNION of sets consists of all elements in either set: it is a larger set than either set alone. That is enough to eliminate one of the possible answers. pi (3.1415926535...) is an irrational number, so it is in the union set of rational and irrational numbers. Is pi a ...
*May 5, 2009*

**Marine Science**

Gills?
*May 5, 2009*

**Math**

You should factor out the GCF. 2q^2 + 22q = -60 2q^2 + 22q + 60 = 0 2(q^2 + 11q + 30) = 0 now divide both sides by 2 q^2 + 11q + 30 = 0 (q + 6)(q + 5) = 0 if 2 numbers multiplied together = 0 then one or both factors must be 0. q + 6 = 0 and/or q + 5 = 0 q = -6 and/or q = -5 ...
*May 5, 2009*

**math**

A coin has no memory. Each flip is independent of any flips that came before. So yes, it is 1/2
*May 5, 2009*

**algebra**

(4y^2)(4x^2) = 16x^2y^2
*May 5, 2009*

**Physical Science**

Energy is the ability to do work. Power is work over time.
*May 5, 2009*

**Pre-Algebra**

-12x + 3y = 48 add 12x to both sides 3y = 12x + 48 divide all terms by 3 y = 4x + 16 ------------------------------ -1/4y - x = 0 start as above: solve for y add x to both sides -1/4y = x multiply all terms by -4 y = -4x Now plug in 3 values for x (such as -1, 0, and 1) and ...
*May 5, 2009*

**Chemistry**

DNA uses complementarity in base pairing. That just means that C bonds with G and A bond with T. So for each base (A, C, T, or G) you bond it to its complementary base. AATCCGTAGCTC TTAGGCATCGAG
*May 5, 2009*

**Chemistry**

Yes. The negatively charged phosphate groups would attract the positively charged regions of the molecules making the polar solvent. For example, if the solvent were water, then the H atoms, which carry a partial positive charge, would be attracted to the negative regions of ...
*May 5, 2009*

**critical thinking**

It depends on the audience. To an objective, rational person, yes, logical arguments are more persuasive than emotional and moral ones. But just consider how many times people resort to emotional instead of logical appeals to try to gain adherents. They are hoping to convince ...
*May 5, 2009*

**math help quickly**

How many hous are in a day?
*May 4, 2009*

**Math riddle**

finding a parking space????? drowning in a bathtub????
*May 3, 2009*

**math**

2 - (x + 4) >= 3 - 2x 2 - x - 4 >= 3 - 2x -x - 2 >= -2x + 3 add x to each side -2 >= -x + 3 subtract 3 from both sides -5 >= -x multiply through by -1, remembering to reverse the direction of the inequality 5 <= x means x >= 5 for interval notation use the...
*May 3, 2009*

**chemistry**

Two oppositely charged particles would accelerate as they approached one another, so their kinetic energy would increase. Since their kinetic energy would increase, and the total of kinetic energy and potential energy is constant, then the potential energy would have to ...
*May 3, 2009*

**Physics**

The sun is not involved in this problem, only the earth. The earth does not rotate around the sun. Rotate means to spin around once on its own axis. The earth revolves around the sun in a year, but rotates around its own axis every ~24 hours. 1) They give you the radius, and ...
*May 3, 2009*

**math (algebra)**

0 ft altitude to 4,000 ft (I assume you made a typo) is an increase of 4,000 ft and a decrease of 7.4 degrees F. 4,000 ft to 8,000 ft is an increase of 4,000 ft and a decrease of 7.4 degrees. 8,000 ft to 12,000 ft is an increase of 4,000 ft and a decrease of 7.4 degrees. So, ...
*May 3, 2009*

**algebra**

The first equation is L = 2W Since for a rectangle A = LW, the second equation is 200yd^2 = LW See if you can take it from there.
*May 3, 2009*

**math**

Do you mean ((x^2)^2)^2? If so, you use the rule (x^a)^b = x^ab, working from the inside grouping outward.
*May 3, 2009*

**Physical Science**

Sound pretty good to me except for (3). A lake would be larger (more volume and more mass) than a swimming pool, so the thermal energy of the lake - which is at the same temp as the pool - would be greater.
*May 3, 2009*

**Math**

The 1 is the only problem. The others are multiples of three and if added together will also produce a number divisible by three. Before any numbers are chosen there are 4 numbers, three of which are NOT the number 1. The probability that the first number chosen will NOT be ...
*May 2, 2009*

**chemistry**

At the level of individual nucleons, a neutron is converted into a proton plus a beta particle (high energy electron) and an electron antineutrino. A proton consists of 2 up and 1 down quark and a neutron consists of 1 up and 2 down quarks.
*May 2, 2009*

**math**

For the first one, I will start you off. 5-2{4-(3y-4)} PEMDAS is the order of operations. You cannot simplify anything in the inner most parentheses, but you can for the curly braces. In essence, you distribute the implicit negative one across the terms in the parentheses. 5...
*May 2, 2009*

**Pre-Algebra**

1) Simply combine like terms on the left carry out the division on the right. 2) Let U = measure of UVW and let X = measure of XYZ. U = X - 16 Since the angles are also complementary, then their sum is 90. U + X = 90. You now have two equations to work with: substitution will ...
*May 2, 2009*

**Still needs help**

For volunteers, the original question has not yet been answered.
*May 2, 2009*

**math**

Check your equation again and see if you typed it correctly.
*May 2, 2009*

**Chemistry**

Try Googling chemsketch. There are free downloads.
*May 2, 2009*

**Physics**

Gravity is the weakest of the 4 fources and plays essentially no role in attraction between microscopic particles. One could eliminate the weak force based on its name (as long as one remembers that it is still stronger than gravity). That leaves the strong force and the ...
*May 1, 2009*

**algebra**

My guess as to what the problem is needing: (4x^2 - 7x + 3) - (3x^2 - 5x) remove parentheses then combine like terms 4x^2 - 7x + 3 - 3x^2 + 5x 4x^2 - 3x^2 - 7x + 5x + 3 x^2 - 2x + 3 Then factor x^2 - 2x + 3
*May 1, 2009*

**math**

I noticed that you have unbalanced parentheses in the (9 - 4/(t^2) + 1 part.
*May 1, 2009*

**chem**

As stated, the answer is wrong. Covalent bonds are stronger than ionic bonds.
*May 1, 2009*

**algebra**

In algebra, you often end up with something like (x + 17)(x - 25) = 0 You solve that for x by setting each factor = 0. x + 17 = 0 and x - 25 = 0 x = -17 x = 25 Just do that in reverse. x = 5 and x = -3 x - 5 = 0 x = 3 (x - 5)(x + 3) = 0 Now use FOIL to get ... x^2 - 2x - 15 = 0
*May 1, 2009*

**math**

Use the equation Tt = 1/Tf + 1/Ts where Tt is the total time, Tf is the first person's time, and Ts is the second person's time. Now just plug and chug.
*May 1, 2009*

**algebra**

3x/2 + 8-4x/7=3 The denominators are 2 and 7, and the LCM for them is their product: 2 x 7 = 14. So multiply through (multiply each term on both sides of the equation) by 14 to eliminate the fractions. 14(3x/2) + 14(8) + 14(-4x/7) = 14(3) 21x + 112 - 8x = 42 combine like terms...
*April 30, 2009*

**Algebra Riddle**

The speed of the lion is greater than or equal to that of the train: otherwise, the train would catch up to run over the lion (and the question says the lion runs in front of the train). Ask a silly question .... Or maybe the answer is, you get lion segments?
*April 30, 2009*