Graham
Most popular questions and responses by Graham
Chemistry
I had a 1.094g of mystery Alum. "AB(SO4)c. dH2O" (I assume that that the Alum is KAl(SO4)212H2O but we don't know A B c or d, we do know that mass percent of water is 51.9) After processing the alum (Ba(NO3)2 and HNO3 through a gooch crucible) we end up
asked on February 1, 2013 
Math
Find how many digits the base seven number 7^(7^7) has when written in base seven.
asked on February 26, 2019 
Calculus
Find the number b such that the line y = b divides the region bounded by the curves y = 4x2 and y = 1 into two regions with equal area. (Round your answer to two decimal places.)
asked on November 18, 2013 
physics
A 2.41 kg ball is attached to a ceiling by a 1.86 m long string. The height of the room is 3.38 m. The acceleration of gravity is 9.81 m/s 2 . What is the gravitational potential energy associated with the ball relative to a) the ceiling? Answer in units
asked on December 6, 2013 
math
dara spent 25% of his money in one shop , he spent 33 1/3 of the remainder and had £6.80 left , how much had he at first
asked on December 15, 2010 
science
If the absolute temperature ooh 6 inches cubed of a gas decreases by a factor of 2, what will be the new volume? How do set up this problem and solve it?
asked on November 18, 2014 
Algebra IIPlease check fpr explanation
I have a question concerning this problem:I just want to make sure my formulas are correct before I do problem It is a hyperbola equation (y4)^2/49  (x6)^2/72 = 1 1.It is a vertical hyperbola, correct? 2. the a^2 is 49, correct? 3. the b^2 is 72,
asked on January 14, 2012 
chemistry
Predict the products and then write the complete balanced chemical equation with states of matter: 1. Sulfuric Acid and sodium hydroxide 2. Aluminum and copper (II) sulfate 3. Silver nitrate and iron (III) chloride 4. Magnesium heated 5. Aluminum oxide
asked on February 8, 2011 
Physics
A satellite moves in a circular orbit around the Earth at a speed of 5.3 km/s. Determine the satellite’s altitude above the surface of the Earth. Assume the Earth is a homogeneous sphere of radius 6370 km and mass 5.98 × 1024 kg. The value of the
asked on October 29, 2013 
Algebra IIplease check
Write the polynomial in simplest form with roots 4, 5i and 5i(multiply it out so no parentheses remain (x4)(x+5i)(x5i)(NOT SURE ABOUT THIS ONE) (x4)(x^225i^22) (x4)(x^2+25) x^3+25x4x^2100 x^34x^2+25x100 Is this correct
asked on January 16, 2012 
chemistry
I'd like to do a titration test, I've got a sulphuric acid solution @ 1M (2N) but I need one @ 0.12N. How many ml of the 1M (2N) solution do I need to add to distilled water to make up 100ml please?
asked on August 2, 2013 
Math
Hi, I have been asked to simplify the square root of 28 by writing it as a product of an integer and a surd. By practising other calculations I have come up with the answer of 2/7 (sorry couldn't do a square root symbol so have used / instead). I think I
asked on January 26, 2010 
maths
Can you tell me how you arrive at the answer to this question: if you multiply meby2, I become a number greater than 20and less than 40. If you multiply me by 6 I end in 8. If you multiply me by4,I end in 2.
asked on May 2, 2011 
maths
How many Sq metres is there in a area of 200cm x195cm x10cm deep?
asked on November 20, 2015 
Maths
the length of a rectangle L metres and the width of the rectangle is W metres. Each measurement is correct to the nearest cm. Find, in terms of L and W the difference between the lower bound and the upper bound of the area of the rectangle.
asked on November 12, 2014

Language Arts
its a fire poem i couldn't find a better one o
posted on March 22, 2018 
Social Studies Help ASAP Please!
a
posted on January 28, 2018 
American Government
shoutout (: you are my god
posted on December 12, 2017 
English
It's B
posted on December 1, 2017 
Algebra II
Let's start here: "Write an equation to determine how far she can drive based on the gallons of gas in her car." So when we write an equation, there's usually an independent and dependent variable. In this case, how far she can drive DEPENDS ON the gallons
posted on September 14, 2016 
math
No, you didn't waste my time, understanding is an important part of learning.
posted on September 14, 2016 
math
So, J = 4, and we have the equation: s + j = 17 You can solve this by substituting 4 for j in that equation.
posted on September 14, 2016 
Math
So, she has 5.5 pounds and wants to split it into 50 bags. This is a division problem. She wants to divide 5.5 pound into 50 bag: 5.5 / 50 Since this is a fraction as well, she could divide both 5.5 and 50 by 5 (same thing as multiplying by (1/5)/(1/5) or
posted on September 14, 2016 
geometry
Do what two recipes? You'll have to be more specific.
posted on September 14, 2016 
math
First of all, don't start a new post every time you ask, reply to the same original one. I assume you're referring to the problem where I answered: "Sam's age is five years more than twice Jessica's age." So, Sam's age, which I will designate a "s" is 5
posted on September 14, 2016 
Algebra
Yeah, if it's coefficient, it's definitely "of". Crossword puzzles are really not the best way to understand math concepts anyway.
posted on September 14, 2016 
MAth
Well, do you know what a function is? A function is an equation where every input has only one output. In notation, x is the input. So the question is really asking: "Can x equal anything in following equation which will result in multiple yvalues?" The
posted on September 14, 2016 
Algebra
Ok, so we've got: _ _ E _ _ _ _ _ _ T My best guess is "Coefficient", given the context, although that is 11 letters.
posted on September 14, 2016 
math
No, that is not correct. If you want better help, show whatever work you've done on the problem. That will help me understand where you aren't understanding. And I've already answered this question twice.
posted on September 14, 2016 
Math/Algebra
If that is the case: Refactor the denominator (bottomm), and you'll get the right answer.
posted on September 14, 2016 
Math/Algebra
I'm assuming the original equation is: (Z^2  8Z + 12) / (Z^2 + Z 6) So, that 8 is actually an 8Z, right?
posted on September 14, 2016 
math 101
Ok, so first, n + 2 > 8 can be simplified: n + 2 > 8 n + 2  2 > 8 2 n > 6 and the replacement set for the variable is all onedigit prime numbers To answer that, we have to know the 1 digit prime numbers, which are {2, 3, 5, 7}. So n can equal any of
posted on September 14, 2016 
math
I already answered this in the previous question, but here it is again: "Sam's age is five years more than twice Jessica's age." So, Sam's age, which I will designate a "s" is 5 years more than twice Jessica's age, which I will designate as "j". From this
posted on September 14, 2016 
math
"Sam's age is five years more than twice Jessica's age." So, Sam's age, which I will designate a "s" is 5 years more than twice Jessica's age, which I will designate as "j". From this we can realize that twice Jessica's age (2j) plus 5 is equal to Sam's
posted on September 14, 2016 
Math Help
"8 less than y" What is would you do to y to get 8 less than y? "is 2" Is means equal in this context. So, 8 less than y = 2
posted on September 14, 2016 
World History
The assignment sounds like two stories: the headline article, which would be on the front page in a real newspaper, and the international article, which could fill up other space that the headline article doesn't fill up, and perhaps continue onto another
posted on September 14, 2016 
Math
So, you know the values of a, b, and c. You have an expression with the variables a, b, and c. Because you know what each variable equals, you can substitute each number for its respective variable. The expression is: a  b + c = And, a = 2 (2)  b + c =
posted on September 14, 2016 
Pre algebra
That should be right, as long as the first term is "2st^2" and not "(2st)^2".
posted on September 14, 2016 
math
Let the folders cost f. Let the rulers cost r. Sarah paid: 8f + 3r Lea paid: 8r + 3f Sarah paid 1.25 more than Lea. 8f + 3r = 1.25 + 8r + 3f 5f = 1.25 + 5r f = 0.25 + r The rulers cost: r = 0.45 .: f = 0.70 Each folder costs 70 cents. Check. 8*(0.70) +
posted on November 1, 2013 
Calculus
f(x) is continuous over the domain. [3,3] f(x) is differential. f'(x) = 3x2 9 f(x) has two equal value points on the independent axis. f(3) = f(3) = 0 Therefore Rolle's Theorem Applies .: Exists c such that f'(c)=0 Solve for c: 0 = 3c2  9 ...
posted on October 10, 2013 
algebra
Redistribute for like terms. = (8+8)m3+(3+3)m2+(14)m+(52) = ...
posted on October 10, 2013 
MathAlgebra
Again, use Pythagorus. d2 = 152 + 152 d = 15√2
posted on October 9, 2013 
MathAlgebra
Use Pythagorus. 122 = 22 + h2
posted on October 9, 2013 
Physics
The centre of gravity is the point around which the weighted distribution of mass of the body sums to zero. Its relative placement within the body is independent of the orientation of the whole body; though of course it is affected by redistribution of
posted on October 9, 2013 
Chemistry
Use: E = hc/λ Where: Planck Constant: h = 6.62606957(29)×10−34J∙s Speed of Light: c = 2.99792458×10+9m∙s1 Wavelength: λ = 0.130m
posted on October 8, 2013 
math
a) S'(t) = dS(t)/dt S'(t) = ((d5t/dt)(t2+1)  5t d(t2+1)/dt)/(t2+1)2 S'(t) = (5(t2+1)  10t2)/(t2+1)2 S'(t) = (55t2)/(t4+2t2+1)
posted on October 6, 2013 
Physics
m1 × 3.10m/s2 = m2 × 2.00m/s2 m2 = 1.55 × m1
posted on October 6, 2013 
chemistry
Use V = m / (w c) Where: V : volume m : mass w : molecular mass c : concentration
posted on October 6, 2013 
Calculus
Don't forget the constants of integration.  A = ∫ √(a2x2) dx Let x = a sin(θ) dx = a cos(θ) dθ A = ∫ a2cos(θ)√(1sin2(θ)) dθ A = ∫ a2cos2(θ) dθ A = (a2/2) ∫ (cos(2θ)+1) dθ A = (a2/2)(sin(2θ)/2 + θ) + C1 A =
posted on October 3, 2013 
Calculus
(B) You have two simultaneous equations in two variables. The original equation, and the derivative for specified values of dy/dx. When dy/dx=1/2 : 1/2 = y/(2yx) Rearrange: 2y  x = 2y Hence: x = 0 Substitute back into y2 = 2 + xy: Therefore: y = ±√2
posted on October 2, 2013 
PreCalculas 11
I cannot see the diagram, so I am going to assume the new fencing is formed into an 'E' shape, with the opening pressed up against the existing fence line. That is: one long side (l), two short sides and the divider (3w). The fence length is: 800 = 3w + l
posted on October 1, 2013 
Math
The 200m fencing is used for two lengthsides (l), two widthsides (w) and the middle divider (w). This: 200 = 2l + 3w
posted on October 1, 2013 
Chemistry
Compare to the tossing two coins. P(Head ∩ Head) = P(Head) × P(Head) = 1/4 P(Head ∩ Tail) = 2 × P(Head) × P(Tail) = 1/2 P(Tail ∩ Tail) = P(Tail) × P(Tail) = 1/4 (Note that there are two ways to toss a head and a tail.) The formation of hydrogen
posted on October 1, 2013 
MATH
Which of what following? ... And what do you think is the right one?
posted on October 1, 2013 
maths
Hint: The first sequence is: 1/(1+1), 2/(2+1), 3/(3+1), 4/(4+1)
posted on September 30, 2013 
la sallle
Three consecutive even integers are: 2n, 2n+2, 2n+4, where n is an integer. The rule is thus: 2(2n+4)/2n = (3/5)(2n+2)  3 Rearranging gives: 0 = 6 n2  19n  20 Find the integer root(s) of this quadratic. Solve for integer n. Use n to find the three
posted on September 30, 2013 
maths
y = 7x + 21 a = 7*8 + 21
posted on September 30, 2013 
MATH
Let N = a.bcd c = d+3 > 3 ≤ c ≤ 9 b = c2 > 1 ≤ b ≤ 7 a = b+c a = 2c2 > 4 ≤ a ≤ 8 c = (a+2)/2 > 3 ≤ c ≤ 5 .: c = 3, N= 4.130... c = 4, N= 6.241... c = 5, N= 8.352... Though of course the rules only fix the first four significant
posted on September 30, 2013 
maths
Hint: the sequence is: 21,22,23,24,25,...
posted on September 30, 2013 
Probability With Cards
The events are independent. Use: P(Ki ∩ ♥) = P(Ki)×P(♥)
posted on September 30, 2013 
Card Probability
There are 52 cards in the deck; 13 in each of the four suits, and two of the suits are red. The four face cards in each suit are: jack, queen, king, and ace. P(face card) = 4/13 P(red) = 1/4 The events are independent. The probability of an intersection of
posted on September 30, 2013 
Dice Probability
No. The probability of the first die rolling a 2 is 1/6. The probability of the second die rolling a 3 is 1/6. The combined probability is 1/36.
posted on September 30, 2013 
chemredox
Opps. Cut and paste error. 2 Ca + Cr2O72 + 14 H+ = 2 Ca2+ + 2 Cr3+ + 7 H2O
posted on September 29, 2013 
chemredox
In acidic aqueous solution you use water to balance oxygen and hydrogen cations to balance hydrogen. Ca = Ca{2+} + 2 ē Cr2O7{2} + 14 H{+} + 6 ē = 2 Cr{3+} + 7 H2O ===================================================== 3 Ca + Cr2O7{2} + 14 H{+} = 3
posted on September 29, 2013 
physics
Hint: What affect does horizontal velocity have on vertical fall? Use: vector displacement equation. x(t) î + y(t) ĵ = [x(0) + u(0)t] î + [y(0) + v(0)t  ½ gt^2] ĵ xt î + yt ĵ = (x0 + u0 t) î + (y0 + v0 t  ½ g t2) ĵ
posted on September 29, 2013 
Math
Check the bracket placement. ±√(10/3) = ±√(10)/√(3) = ±√(30)/3 = ±(⅓)√(30)
posted on September 29, 2013 
Chemistry
An ionic exchange reaction only occurs when dissolved ions are removed from solution as (1) a precipitate (solid), (2) a gas, or (3) form a molecule that remains in the liquid phase. Sodium and Potassium Biphosphates (and Phosphates) are soluble.
posted on September 29, 2013 
Math
When y = 0 then x = 1. As y rises towards positive infinity, x rises towards positive infinity. As y falls towards negative infinity, x falls towards 0. There is no real value of y corresponding to any negative value of x. ∞ ≤ y ≤ +∞ 0 ≤ x ≤
posted on September 29, 2013 
Computer Science
The main should declare and load the list structure (or object), and also a variable to hold the result. The list structure cannot be fixed length; it needs to grow arbitrarily long. You'll also need a way to input numbers into the list. Given your modular
posted on September 28, 2013 
Calculus & Vectors
Use z = x + yi Plot on the Cartesian (x,y)plane a) Plot (x, y) = (2, 0) b) Plot √(x^2 + y^2) = 2 c) Plot (x, y) = (5, 4) d) Plot (x, y) = (√2, √2)
posted on September 28, 2013 
physics
Rearrange the equation: A = F_x / t^2 Then simply substitute the numbers: .: A = (781.25/1.45^2) N/s^2 Answer in three significant figures.
posted on September 28, 2013 
math
Do you mean: 4 (x^2 + x) / (x3x) = 2 (x+1) = 2x 2
posted on September 28, 2013 
Math
Consider the quadratic: 9z^2  148z + 64 Its roots are: (148 ±√(219042304))/18 = (148±140)/18 .: either 4/9 or 16 Thus we can factorise the quartic: 9x^4  148x^2 + 64 = (9x^2  4)(x^2  16) Next, factorise each of these two quadratic terms in turn.
posted on September 28, 2013 
math
Please be clearer. What does the bracketed 4 mean? Is everything to the right of the division sign on the denominator, or just the first x?
posted on September 28, 2013 
math
Yes. Exactly. (x^2 7x 8) / (x+1) = x + (8x 8)/(x+1) = x 8
posted on September 28, 2013 
chemistry
(CH3)2NH + H2O = (CH3)2NH2{+} + OH{} Kb = [(CH3)2NH2{+}] [OH{}]/[(CH3)2NH] At 11.98 the contribution of OH{} concentration from dissociated water is negligible. [OH{}] = 10^(11.9814.00) [(CH3)2NH2{+}] = [OH{}] [(CH3)2NH] = 0.164M  [OH{}] Kb =
posted on September 27, 2013 
Science
You simply need to express 2.16 micrometres in 5.0 seconds as some kilometres per hour, retaining the appropriate number of significant figures during conversion. 1 μm = 1×10^–6 m 1 km = 1×10^+3 m 1 hr = 3600 s 2.15μm / 5.0s = _._ ×10^__ km/hr
posted on September 27, 2013 
Physics
Use the classical mechanic equations of force, displacement, and velocity under constant acceleration from rest. (1)... F = m a (2)... s = a t^2 /2 (3)... v = a t From (1), doubling the force will double the acceleration (for the same mass). From (2),
posted on September 27, 2013 
Significant figures
The count of significant figures for the product is the least count of significant figures of the terms. To determine how many significant figures to use, count the significant figures of each of the terms and use the least one.
posted on September 27, 2013 
AP CHEM
This question is incomplete. It contains insufficient information to answer.
posted on September 26, 2013 
Combinatorics
C(4,1) C(5, 1) C(6, 1) = (4!/1!3!) (5!/1!4!) (6!/1!5!) = ...
posted on September 26, 2013 
Math
x ≤ 1
posted on September 25, 2013 
Math
6 ≤ 4 + (2x) 2 ≤ 2x x ≤ 1
posted on September 25, 2013 
chemistry
You have 5.6 mL of NH3. There are 22.4 L per mole of gas at STP. So 5.6e3 / 22.4 mole of NH3. Balance the equation to determine the corresponding number of H2.
posted on September 25, 2013 
calculous
cannot see figure.
posted on September 25, 2013 
physics
Given: v1 = 34.5 [cos(50°) W + sin(50°) N] km/hr v2 = 16.1 [0 W + 1 N] km/hr Let: s = 3 v1 + 0.5 v2 Find: s s = (3*34.5*cos(50°)) W + (3*35.6sin(50°)+0.5*16.1) N s = √((3*34.5*cos(50°))^2 + (3*35.6sin(50°)+0.5*16.1)^2)
posted on September 25, 2013 
calculus
ln(2) = 0.69314718... (A) P(6)/P(0) = 2 .: k_g = ln(2) /6mth (B) P(3mt) = 4000 e^{3 k_g} (C) k_d = ln(2) /10day
posted on September 25, 2013 
physics
The same current flows through the same crosssectional area, but with only half the diameter, P has only ____ the area. Thus it passes ___ the current. [If you halve the diameter what happens to the area?]
posted on September 24, 2013 
Chemistry
You also need the molar mass of water. Let x represent the amount of sodium sulfate in the sample. Solve these simultaneous equations: 142.05 x + 18.015 nx = 8.5 18.015 nx = 4.776
posted on September 24, 2013 
physics
Using the standard orthogonal unit vectors î and ĵ. Momentum of the system: 0.045*9.0 î  0.145*7 ĵ kg∙m/s Magnitude: √((0.045*9.0)^2 + (0.145*7)^2) kg∙m/s Direction: angle measured off xaxis arctan((0.145*7)/(0.045*9.0))
posted on September 23, 2013 
Physics
If a 100%efficient engine transfers 100% of the fuel's energy to work then, 0% of the fuel's energy would be wasted as heat, vibration, or otherwise. If it extracts 100% of the available energy from the fuel then anything left will have 0% available
posted on September 23, 2013 
math
Let the number of Zerg be z, and Borges be b. Heads: 45 = z + 4b Feet: 55 = 3z + 2b Solve the simultaneous equations. Hint: multiply the first by 2 and subtract the second, then simplify. Hint 2: multiply the second by 3 and subtract the first, then
posted on September 22, 2013 
math
Let the number of Zerg be z, and Borges be b. Heads: 45 = z + 4b Feet: 55 = 3z + 2b Solve the simultaneous equations. Hint: multiply the first by 3 and subtract the second, then simplify. Hint 2: multiply the second by 3 and subtract the first, then
posted on September 22, 2013 
physics
Solve for t to find the breaking time. 0 = 19m/s  t_b 4.6m/s^2 Substitute to find the breaking distance. d = t_b 19m/s  t_b^2 2.3m/s^2 Find the time to travel to that point. t_d = (48.2m  d) / 19m/s.
posted on September 22, 2013 
Chemistry is this correct?
Yes. 34m/s = 34m/s * 1000mm/m * 60s/hr = 2040000mm/hr ≈ 2.0×10^6mm/hr
posted on September 22, 2013 
Physics
Given: speed of v = 30[m/s] radius of r = 25[m] Use: Centipetalacceleration of: a_c = v^2/r
posted on September 22, 2013 
Physical Chemistry
∫ β δT = ∫ 1/V δV Since β independant of T, ∫ β δT = βT + constant. βT = ∫ 1/V δV Use ∫ 1/x dx = ln(x) + constant βT = ln(V) + constant .: V = k e^(βT)
posted on September 22, 2013 
Science
Let u be the horizontal speed and v the vertical. u(0)=8.0m/s, v(0)=0m/s Let x be the horizontal height and y the vertical. x(0)=0m, y(0)=20m y(t) = y(0) + v(0) t (9.81/2) t^2 Find t when y(t) = 0m So: 0m = 20m  4.905(m/s^2) t^2
posted on September 22, 2013 
Algebra
If n is the least of the three consecutive odd numbers, the others are: n+2, n+4. So: 5(n) +35 = 2(n+2+n+4) Solve for n, then find 3n+6
posted on September 22, 2013 
Math
A(x+5)+2(−Bx+2) = (A2B)x+(5A+4) So: (A2B) = 17 (5A+4) = 219 Solve the second for A, substitute into the first and solve for B, then find AB.
posted on September 22, 2013