RickP

If you are studying the eye, look up the difference between rods and cones: one type (I won't say which one) is very sensitive but does not let us see color, whereas the other requires a lot of light but does allow us to see color.

16 years ago

The seasons are not caused by the earth being different distances from the sun: the earth's orbit is only slightly elliptical - it is essentially circular. The seasons are caused be the axial tilt of the earth. So if there were no tilt, there would be onl...

16 years ago

A higher resistance should generate more heat. Which do you think is hotter, the glowing filament in a light bulb or a copper wire? DO NOT TRY TO TOUCH EITHER!

16 years ago

If there is no relative motion between you and the bus, then you could never reach the back of the bus no matter how long you kept walking. But you would, so there must be relative motion between you and the bus.

16 years ago

Let's start with the basics. V = IR But the form you need is solved for the electric current. 1) Which variable is that? 2) Can you solve the above equation for that variable? 3) One of the variables remains constant for a, b, and c. Which variable is tha...

16 years ago

Whatever book you are using for electronics must have a definition for short circuit. Why not post it and then indicate exactly what part of it are you having trouble with? PS: Wikipedia says ... ************************************ Definition A short cir...

16 years ago

The question is ambiguously stated. It apparently means that you are INSIDE the bus walking towards the back of the bus.

16 years ago

The planets orbiting a star can make it "wobble", because while it is obvious that the star gravitationally influences the motion of the planets, gravitational attraction is a two-way affect, and the planets also influence the star's motion (though since...

16 years ago

They can either share electrons with other atoms (forming covalent bonds) or gain/lose electrons with other atoms (forming ionic bonds).

16 years ago

For (1), consider this as a starter. A car travels due east for 30 miles, then turns due north and travels for another 40 miles. What is the distance? What is the displacement? I won't say which one, but the distance and displacement form a right triangle...

16 years ago

For (a), consider Newton's third law. For (d), consider accleration in the form of the equation: a = (Vf - Vi) / t where a is acceleration, Vf is final veloctiry, Vi is initial velocity, and t is the elapsed time. Or more simply, consider acceleration to...

16 years ago

You description was cut off. Product (you have to keep track of what you sell and what customers order) Order (you have to keep track of orders) Customer (not absolutely necessary - you could just enter the Customer information for each order, if you are...

16 years ago

A few excerpts from pages 8 & 9 of Scott Mueller's "Upgrading and Repairing PCs: 18th Edition" "... 1952 The UNIVAC I delivered to the U.S. Census Bureau is the first commercial computer to attract widespread attention. ... 1954 A silicon-based junction t...

16 years ago

Here are some of the main parts: you will need to look up their functions (you have to do some of the work). HARDWARE motherboard processor (CPU) memory (RAM) case/chassis power supply hard drive CD or DVD drive keyboard mouse monitor SOFTWARE OS (operati...

16 years ago

W = fs where W is work, f is force, and s is the distance through which the object was moved (PS: we assume that the force is in the direction of motion, not at a angle to it). Plug in and solve.

16 years ago

KE = 1/2 mv^2 where KE is kinetic energey, m is mass, and v is velocity. Plug in and solve.

16 years ago

Start by figuring out the change in gravitational potential energy of the backpack, then relate that energy to work.

16 years ago

x intercept: y = 3x^2+18x 0 = 3x^2+18x 3x is common to both terms on the right: factor it out. 0 = 3x(x + 6) If 2 values are multiplied together and the product is 0, then one or both of the values must be 0. 3x = 0 and/or x + 6 = 0 Take it from there.

16 years ago

Also, you are not adding up the molarity of the compound. Molarity is numer of moles of solute per liter of solution.

16 years ago

Jacob's answer explains it better, but there is an equation you can use. Tt = 1/T1 + 1/T2 where Tt is total time, T1 is the first person's time, and T2 is the second person's time (this can be carried out as far as needed, such as by adding a 1/T3 term, a...

16 years ago

A codon consists of 3 consecutive bases in mRNA, with those 3 bases coding for a particular amino acid (or "stop"). Examples of codons would be AGU, AAG, CGU, GCA, etc. The mRNA is transcribed from DNA, so each codon in mRNA is complementary to a triplet...

16 years ago

Without parentheses, you would divide 2.6 x 10^9 by 2.49, then multiply that result by 10^8. So at a minimum you need to use one set of parentheses: 2.6 x 10^9 / (2.49 x 10^8)

16 years ago

The question is worded poorly. It might be that the experiment is supposed to show something like: the temperature of water with lots of ice in it does not increase when heated, until the ice has melted. The heat energy goes into disrupting the hydrogen b...

16 years ago

6) is wrong too (I didn't get any further). 6) 4^11/4^8*4^-2 = 4^5 PEMDAS (Please excuse my dear aunt sally). Parentheses exponentiation multiplication & division (left to right) addition & subtraction (left to right) Because multiplication and division h...

16 years ago

Let f = father's age and s = son's age. "the father's age is three times his son's age" f = 3s "the difference between a father's age and his son's age" f - s If we want to know f - s, and have f = 3s, then we need to subtract s from the left side. And wh...

16 years ago

Energy is the ability to do work. The two main types are kinetic energy (the energy of motion) and potential energy (stored energy). Anything moving (relative to you) has energy because it has kinetic energy. But things that are not moving (relative to yo...

16 years ago

Without commas in the English phrasing, it would be 3x + (15/2).

16 years ago

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.

16 years ago

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 =...

16 years ago

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 segme...

16 years ago

I think Ms. Sue made a typo. It is 1 1/2 cupcakes.

16 years ago

I could, but you haven't shown that you've put any effort into doing so yourself. Also, your third homework question you want someone to do for you is missing a term.

16 years ago

The terms are in descending order, so a = 4, b = -35, and c = -9. find 2 numbers that when multiplied give you a * c (which is 4 * -9 = -36) and when added give you b (which is -35). Try -36 and 1. When multiplied they equal -36, and when added they equal...

16 years ago

How many ounces are in a pound? 16. So you multiply the number of ounces (z) by 16 to get the pounds. Therefore, p(z) = 16z The selling price (s) is the original cost (c) plus 45%. That is 1.45 * cost, or 1.45c. Therefore, s(c) = 1.45c

16 years ago

Starting off, there are 105 items, of which 30 are bats. The probability for that draw is 30/105. There are now 104 items remaining, of which 15 are gloves. The probability of getting a glove now is 15/104. There are now 103 items remaining, of which 60 a...

16 years ago

When adding numbers with unlike signs, subtract the larger absolute value from the smaller absolute value, then keep the sign of the number that had the larger absolute value. -3 + 5 absolute values are 3 and 5: the larger absolute value is 5, which start...

16 years ago

Mistake in my wording (not in my solving). When adding numbers with unlike signs, subtract the SMALLER absolute value from the LARGER absolute value, then keep the sign of the ORIGINAL number that had the larger absolute value.

16 years ago

When adding numbers with like signs, add their absolute values then retain the sign. -2 -8 -2 + (-8) absolute values are 2 and 8 2 + 8 = 10 keep the negative sign from the original numbers, so the answer is -10

16 years ago

a population of 600 plants contains 294 AA, 252 Aa, and 54 aa individuals. the AA and Aa produce purple flowers while the aa plants produce white flowers. what are the frequencies of the following? please show work or explain how you got it. please A. All...

16 years ago

The genotype frequencies are much easier to calculate. F(AA) = # of AA individuals / 600 F(Aa) = # of Aa individuals / 600 F(aa) = # of aa individuals / 600

16 years ago

A population that meets Hardy-Weinberg requirements is in genetic equilibrium, and neither its allele frequencies nor its genotype frequencies changes from generation to generation. If allele and genotypes frequencies are not changing from generation to g...

16 years ago

In H-W equilibrium, the 3 genotype frequencies are p^2 + 2pq + q^2 = 1 where p is the frequency of the dominant allele (A, which is 0.8) and q is the frequency of the recessive alleled (a, which is 0.2). (0.8)^2 + 2(0.8)(0.2) + (0.2)^2 = 1 0.64 + 0.32 + 0...

16 years ago

As stated, the answer is wrong. Covalent bonds are stronger than ionic bonds.

16 years ago

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 ge...

16 years ago

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

16 years ago

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

16 years ago

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 stro...

16 years ago

Try Googling chemsketch. There are free downloads.

16 years ago

Check your equation again and see if you typed it correctly.

16 years ago

For volunteers, the original question has not yet been answered.

16 years ago

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 wi...

16 years ago

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 i...

16 years ago

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.

16 years ago

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...

16 years ago

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.

16 years ago

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

16 years ago

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.

16 years ago

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...

16 years ago

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...

16 years ago

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 th...

16 years ago

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 energ...

16 years ago

finding a parking space????? drowning in a bathtub????

16 years ago

How many hous are in a day?

16 years ago

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...

16 years ago

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?

16 years ago

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 a...

16 years ago

Can you do the first part, of simplifying the inequality?

16 years ago

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 "If the lesser of...

16 years ago

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

16 years ago

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".

16 years ago

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...

16 years ago

Gills?

16 years ago

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...

16 years ago

(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) -...

16 years ago

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

16 years ago

(4y^2)(4x^2) = 16x^2y^2

16 years ago

Energy is the ability to do work. Power is work over time.

16 years ago

-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 a...

16 years ago

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

16 years ago

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...

16 years ago

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 a...

16 years ago

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 (ne...

16 years ago

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 (ne...

16 years ago

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 in...

16 years ago

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...

16 years ago

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 +...

16 years ago

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.

16 years ago

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 =...

16 years ago

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 f...

16 years ago

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

16 years ago

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.

16 years ago

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 alm...

16 years ago

What exactly is Lucky Coin? What is the probability of winning given a single shot?

16 years ago

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

16 years ago

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

16 years ago

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.

16 years ago

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.

16 years ago

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.

16 years ago

How did Mendel allow a single garden pea plant to reproduce with itself?

16 years ago

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...

16 years ago