Tuesday

October 21, 2014

October 21, 2014

Total # Posts: 18,972

**algebra/please help I have been wrong twice**

p(oil) = 1/40 p(gas) = 1/20 p(oil and gas) = 1/800 so (1/40)(395,000) = 9875 (1/20)(125,000) = 6250 (1/800)(520000) = 650 So I get 16,775 income - 25,000 expense = -8225 They expect to lose money I think.
*May 28, 2014*

**PRECAL MULTIPLE CHOICE**

sin A/a = sin B/b sin B = (b/a) sin A = 1.036 no solution (sin may not be greater than 1)
*May 28, 2014*

**math**

f' = -12 x^2 + 16 x + a f" = -24 x + 16 sheds water when when f" is negative holds waster when f" is positive f" is 0 when x = 2/3 sheds water when x < 2/3 holds water when X>2/3 so B
*May 28, 2014*

**math**

f(4) = 64 f(1) = 1 63/3 = 21 = average slope in interval f' = 3 x^2 = 21 x = +/- sqrt 7 in interval x = sqrt 7 = c so A
*May 28, 2014*

**Physics**

g is about 32 ft/s^2 in these obsolete units 61.8 miles/hr * 5280 ft/mi * 1 hr/3600seconds = 90.6 ft/s 7 * 32 = 224 ft/s^2 a = change in v/change in tim 224 = 90.6/t t = .4 seconds
*May 28, 2014*

**Science**

+2e
*May 28, 2014*

**Science**

By the way, remember transportation losses and expenditures including expense and losses of electrical cables particularly under sea.
*May 28, 2014*

**Science**

Actually I did not intend to write a PhD thesis before lunch. Post your attempt first please. Use the sources you have learned about (coal, oil, natural gas (fracked or otherwise) , nuc, hydro, wind, waves, solar panels etc )
*May 28, 2014*

**physics**

away of course in general for non-relativistic Doppler effect f heard = f emmitted (c+vr)/(c+vs) c = v of wave vr = v receiver (plus if toward source) vs = v source, (plus if source moving away from receiver) use your c of sound 78 = 80 (c+0)/(c+vs)
*May 28, 2014*

**calculus**

Horizontal speed constant forever = 80 cos 45 = u = 56.6 ft/s Initial vertical speed Vi = 80 sin 45 = 56.6 ft/s Now you did not give me the quadratic so I will have to solve it with physics v = Vi - g t where g = about 32 ft/s^2 in these obsolete units then h = Hi + Vi t - 16 ...
*May 28, 2014*

**English**

I think it could mean one of two things: 1. Instead of arguing about who would pay how much, I "simply" picked the bill up. 2. I "just" picked the bill up a minute ago.
*May 28, 2014*

**Math**

2/50 - 75/50 = -73/50
*May 28, 2014*

**technology**

work in = work out 10 * 100 = F * 20 F = 50 N
*May 28, 2014*

**Physics**

volume of man = 75 liters so density of man = 80 kg/75 L = 1.067 kg/L x(fat density ) + (1-x)(bone density) = 1.067 .9 x + 1.1 (1-x) = 1.067 1.1 - 1.067 = (1.1-.9)x x = .167 or 17%
*May 28, 2014*

**Algebra 1**

sorry, read reply wrong. You have it fine
*May 28, 2014*

**Algebra 1**

number or blacks = b number of whites = b+10 total - b +b+10 = 2 b+10 black first b/(2b+10) now we have b-1 blacks we have b+10 whites still total = 2b+9 b/(2b+10) * (b+10)/(2b+9) note - not 2b+10 in numerator
*May 28, 2014*

**trig**

rise = .1 run tan theta = .1 theta = 5 deg
*May 27, 2014*

**algebra**

36 possible outcomes if order matters If it is the sum that matters you have to figure a different probability for every sum for example there are 4 ways of getting a sum of 5 1+4 or 4+1 2+3 or 3+2 to get a sum of 6 though, there are 5 ways 1+5 or 5+1 2+4 or 4+2 3+3 On the ...
*May 27, 2014*

**algebra**

I suspect they mean including 1 and 100 and not 2 through 99 so 100 numbers total so 5, 10, 15 ...... 100 are multiples How many? 10 * 2 = 20 20/100 = 1/5 so 1 - 1/5 = 4/5
*May 27, 2014*

**Trig**

current north speed = 3.2 sin 38=1.97 N current west speed = 3.2 cos 38 = 2.52 W Total North speed = 8.5+1.97 = 10.47 Total west speed = 2.52 tan theta = 2.52/10.47 theta = 13.53 degrees west of north or 47.47 degrees north of west Is the direction you are GOING (you are still...
*May 27, 2014*

**trig**

cos 35 = h/15
*May 27, 2014*

**Physics**

Yes, if the friction was less than the force required to accelerate the upper block, it would accelerate more slowly than the bottom one. In other words slip :)
*May 27, 2014*

**Physics**

You are welcome :)
*May 27, 2014*

**Physics**

F = - k x = -130 (.1) = -13 N if they do not slip m = 6.25 kg a = 13/6.25 = 2.08 m/s^2 force required to accelerate small block = 1.25 *2.08 = 2.6 N do we have that much? weight = m g = 1.25 * 9.81 so max friction = .3*1.25*9.81 = 3.68 N so no slip :)
*May 27, 2014*

**Math? Check Answers Please!!**

You are welcome :)
*May 27, 2014*

**Math? Check Answers Please!!**

1) yes 2)4^4 * 4^6 = 4^(4+6) = 4^10 3)4^(4+44) = 4^48 4) 3^(4-4) = 3^0 = 1 note ANYTHING^0 = 1 5) 3^-3 = 1/3^3 = 1/27 yes
*May 27, 2014*

**Physics**

2.05 2.04
*May 27, 2014*

**Physics**

initial momentum forward = (69.5+.47)(2.15) = 150.4 so 150.4 = 69.5 v + .470*16 in second part v ball = 2.15 + 16 = 18.15 m/s 150.4 = 69.5 v + .470*18.15
*May 27, 2014*

**Science**

Thanks for catching that !!!
*May 27, 2014*

**Science**

You have to add heat so endothermic 129 J per 2 mol 1 mol = 23 + 1 + 12 + 48 = 84 grams 2 mol = 168 grams we only have 18.5 grams so (18.5/168)129 = 14.2 Joules
*May 27, 2014*

**Physics**

change in x momentum = 2 * mass * x velocity = 2 * .275 * 4.5 sin 35 force on ball by wall = change in momentum /time = change in momentum/.008 wall on ball is -x so ball on wall is + x direction
*May 27, 2014*

**Math Homework: Check Answers**

You are welcome.
*May 27, 2014*

**Math Homework: Check Answers**

1. Suppose you earned 8t - 3 dollars on Monday and 6t + 5 dollars on Tuesday. What were you total earnings? Simplify your answer. A) 2t + 2 B) 2t - 8 C) 14t + 2 D) 14t - 8 Answer: A ------------------------------- 8t+6t= 14 t !!! so 14 t + 2 -------------------------------- 2...
*May 27, 2014*

**physics**

r w^2 = Ac = 6*10^5*9.81 w^2 = 58.9 * 10^5 /.02 = 29.4 *10^7 = 2.94 * 10^8 w = 1.72 * 10^4 = 17,200 radians/sec
*May 27, 2014*

**probability**

-->1 2 3 4 5 6 1 ----- * 2 ----* 3 --* 4 * 5 6 36 possible outcomes get 5 from four of them so p = 4/36 = 1/9 (1/9)180 = 20 times
*May 27, 2014*

**geometry**

Area of base = (1/2)(.25)(.25 sin 60) = .0271 m^2 .0271 * h = 7.5 h = 277
*May 27, 2014*

**physical science**

You are welcome :)
*May 27, 2014*

**physical science**

see below I got 94 %
*May 27, 2014*

**physical science**

100( power out ) /power in 100*3760/4000 = 94 %
*May 27, 2014*

**Geometry**

between 0 and 1 hour Ann went 3 miles per hour between 1 hour and 4 hours, Ann went 2 miles (5-3) so 2 miles /3 hours = .67 mph between 4 hours and 7 hours Ann went zero miles (5-5) so zero miles/hour (lunch break?) between 7 ours and 10 hours (3 hours) Ann went 5 miles (10-5...
*May 27, 2014*

**ALGEBRA! URGENT. Check Answers!**

You are welcome.
*May 27, 2014*

**ALGEBRA! URGENT. Check Answers!**

yes
*May 27, 2014*

**ALGEBRA! URGENT. Check Answers!**

in #3 + 5x - 7x = NEGATIVE 2 x #4 negative 7
*May 27, 2014*

**math**

bottom = pi r^2 top = pi r^2 side = 2 pi r h
*May 27, 2014*

**Physics, am i right?**

If you have a whole bunch of resistors in parallel you can do 1/R = 1/R1+ 1/R2 + 1/R3 + 1/R4 .... Since the current has a choice which resistor to go through, you are adding CONDUCTIVITIES (inverse of resistance) C = C1+C2+C3 ... then in the end R = 1/C or you can do them ...
*May 27, 2014*

**Physics, am i right?**

You are very welcome :)
*May 27, 2014*

**Physics, am i right?**

R = 10*20 /30 = 20/3 i = 9 /(20/3) = 27/20 = 1.35 Amps Yes !
*May 27, 2014*

**calculus**

(14x + 4)cos(7x^2 + 4x)dx,substitution u = 7x^2 + 4x. u = 7 x^2 + 4 x du = 14 x dx + 4 dx = (14x+4)dx so we have integral of cos u du which is - sin u + c - sin (7x^2+4x) + c
*May 27, 2014*

**calculus**

u = x3 + 5x2 + 18 then du = 3 x^2 dx + 10 x dx so in fact we have u du integrate u^2/2 + c so the hard part is squaring .5 (x^3 + 5 x^2 + 18)^2 + c
*May 27, 2014*

**histoy**

Life tenure is democratic NO ! Important people have special rights in a democracy NO People vote in a democracy YES Some slaves freed? What about the rest ? Not the question anyway. Some democracies had slaves (Athens, USA). They may not be proud of it.
*May 27, 2014*

**Physics**

R = 10*30 / (40) = 7.5 45/7.5 = 6 Amps
*May 27, 2014*

**Physics**

10 in PARALLEL with 30 1/R = 1/R1 + 1/R2 or R = R1 R2 /(R1+R2)
*May 27, 2014*

**Physics**

NO!!!
*May 27, 2014*

**algebra**

P(mean of A) if mean P(A) = .6 If we have six Apples and four Oranges in a box then P(A) = .6 when we draw one thing at random. If we have a whole bunch of boxes and on the average there are six apples in each then P(A) = .6 BUT The probability that we will draw that mean on ...
*May 27, 2014*

**algebra/Can you see if I am right**

Probability of the first one being a king is 4/52 probability of the first one being a face card = 12/52 the probability of the second one being a face card if the first was a king is 11/51 so if you mean probability of choosing a king, then a face card it is 4/52 * 11/51
*May 27, 2014*

**physics**

I have no idea.
*May 27, 2014*

**math**

add x to both sides x + y = a add -y to both sides x = a - y
*May 27, 2014*

**general chemistry**

Number of mols/liter
*May 27, 2014*

**math**

Instead of posting it again, read what you posted. It is incomplete. What is K and what does it have to do with the problem. We do not know the ratio of speeds for walking or taking the bus.
*May 27, 2014*

**Physics**

V = i R 20 = i (10) i = 2 amps so yes, b
*May 27, 2014*

**algebra/check my answer**

find probability that NONE are heads (1/2)^3 = 1/8 so we want 1 - 1/8 = 7/8 agree with you
*May 27, 2014*

**Calculus**

y^2 + 4 y = -8 x + 12 y^2 + 4 y + 4 = -8 x + 16 (y+2)^2 = -8 (x-2) vertex at (2,-2) opens left etc
*May 27, 2014*

**algebra**

You are welcome.
*May 27, 2014*

**algebra**

out of 13 men, 12 are bald? 12/13
*May 27, 2014*

**7th grade Math (polynomials)**

maybe: -8.5 x^3 + 0 x^2 + 1.1 x + 0
*May 27, 2014*

**algebra**

(-3)^2 -4(-3) + 3 9 + 12 + 3 24
*May 27, 2014*

**math**

7! = 7*6*5*4*3*2*1 = 5,040 agree
*May 27, 2014*

**maths**

10 *(10^x)^2 - 7 (10^x) = 26 let z = 10^x 10 z^2 - 7 z -26 = 0 ( z - 2)( 10 z + 13) = 0 10^x = 2 or 10^x = -1.3 if you log is base 10 log 10^x = x = log 2 but if x = log a then log a = log 2 so a = 2 similarly log 10^x = x = log (-1.3) but not allowed :)
*May 27, 2014*

**science (check!)**

agree, If the predator is not to run out of food, he needs a lot of prey per predator.
*May 27, 2014*

**Math, grade 10**

anyway a^2 + (17-a)^2 = 185 a^2 + 289 - 34 a + a^2 = 185 2 a^2 - 34 a + 104 = 0 a^2 -17 a + 52 = 0 (a- 13)(a-4) = 0 a = 4 or 13 so they are 4 and 13 and my initial thought was wrong
*May 26, 2014*

**Math, grade 10**

not real numbers 17^2 = 289 which is greater than 185
*May 26, 2014*

**please help**

Well, I had a dislocated shoulder once.
*May 25, 2014*

**Algebra II**

By the way, there are an infinite number of solutions. eg 3 cos (4x - 7 pi/2)+4 or - 3 cos(4x -pi/2) + 4 etc
*May 25, 2014*

**Algebra II**

You are welcome :)
*May 25, 2014*

**Algebra II**

also in your explanation explain that the cosine curve is 90 degrees or pi/2 radians behind the sine curve if you graph y = sin theta and y = cos theta versus theta
*May 25, 2014*

**Algebra II**

trig identity: sin theta = cos (pi/2-theta) so y = 3 sin (4x-pi) + 4 but from above trig identity y = 3 cos [ pi/2 - (4x-pi) ] + 4 or y = 3 cos (-4x + 3 pi/2) + 4 but cos (- theta) = cos theta so y = 3 cos (4x-3 pi/2) + 4
*May 25, 2014*

**PRECALC QUESTION**

6 x +0 y = -24 so x = -4 -4 x + .5 y = 19 so y = 6 -6 + 0 = -6 true (-2)(-2) + (1)(1) = 5 true
*May 25, 2014*

**3D Shapes & Scale**

I mean big surface area for its weight
*May 25, 2014*

**3D Shapes & Scale**

by the way the ant is not only immensely strong for its weight but that A - k L^2 ratio means it has a big surface area for its length. Therefore it's terminal velocity is much lower than yours.
*May 25, 2014*

**3D Shapes & Scale**

1) Archimedes holds you up in the ocean. Water is about 800 times as dense as air. In fact it is about the density of most animals, including people and whales. Therefore when you are in the water you need to exert very little force to hold yourself up. Similarly a whale is ...
*May 25, 2014*

**3D Shapes & Scale**

L2 = 10^3 L1 Area 2 = (10^3)^2 = 10^6 Area 1 volume 2 = (10^3)^3 = 10^9 volume 1
*May 25, 2014*

**Ed Tech**

By the way, if you include analog as well as digital computers, I was using tube varieties as late as 1964 for simulation of ship motions and vibration measurement and analysis.
*May 25, 2014*

**Ed Tech**

Code breaking was one use but the use I am familiar with is generation of tables solving spherical triangles for navigation by sextant. Using a companion volume " Nautical Almanac" you looked up where a ray from the sun or moon or star intercepted the surface of ...
*May 25, 2014*

**Earth Science Regents!!!**

Laruen: Google "celestial navigation".
*May 25, 2014*

**need help1 what function to use? math**

That is correct
*May 25, 2014*

**ALGEBRA**

sorry, 4200-x
*May 25, 2014*

**ALGEBRA**

4300 - x
*May 25, 2014*

**Math**

I assume you mean with integer lengths L + w = 10 L = 5, w = 5 as you said L = 6, w = 4 L = 7, w = 3 L = 8, w = 2 L = 9, w = 1 the ones with w>L do not count because they are indistinguishable from the ones we have now. , So, 5.
*May 25, 2014*

**chamastry**

a mL IS a cm^3 p v = n R T P1 V1/T1 = P2 V2/T2 if n and R constant I guess you want the pressure to be the same? then V1/T1 = V2/T2 so T2 = (V2/V1)T1 T2 = (40/500)400 T2 = 32 k very cold
*May 25, 2014*

**Physics**

Since you do not specify, I will assume 60 degrees from horizontal tan 60 = mg/(m v^2/r) v^2/r = g/tan 60 v^2 = g r/tan 60 v = sqrt(981/tan 60) v = 23.8 m/s
*May 25, 2014*

**math trig**

cos 38 = h/3.8
*May 25, 2014*

**math**

maybe you mean 3^(2x) - 3^(x+2) + 8 = 0 let z = 3^x z^2 - 9 z + 8 = 0 (z-8)(z-1) = 0 z = 1 or z = 8 x = 0 or x = 2
*May 25, 2014*

**English III**

LOL - Who led the troops who arrested John Brown ?
*May 24, 2014*

**English III**

The tone is certainly firm. Of course the effect is wishy-washy in that if you are a slave you are only to be freed if you are in an area in rebellion. If you happen to be a slave in a state that did not rebel, well you better wait for a constitutional amendment.
*May 24, 2014*

**English III**

I agree with you.
*May 24, 2014*

**algebra1a**

first equation is 2 x + 6 y = -4 second equation is 2 x + 6 y = -4 the same, no intersecting lines, no solution
*May 24, 2014*

**Algebra**

remaining = x walked = 3 x 3 x + x = 1164 4 x = 1164 x = 291
*May 24, 2014*

**History: Check My Answers PLEASE**

I may be anticipating the next chapter :)
*May 24, 2014*

**History: Check My Answers PLEASE**

Which are accurate descriptions of how the Christian church influenced daily life in the Middle Ages? Choose all answers that are correct. A.encouraged people to rebel against unjust feudal lords B. oversaw the writing of wills and contracts C. made and enforced the rules and ...
*May 24, 2014*

**History: Check My Answers PLEASE**

A. Most were weakened and eventually overthrown by feudal lords. B. Their power was held in check by parliamentary bodies elected by freemen. C. They were required to ask the pope's permission before they could wage war. D. Many extended their control and left larger ...
*May 24, 2014*

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