Sunday
May 29, 2016

Posts by bobpursley

Total # Posts: 40,892

geometry
no table?
May 28, 2016

Bio
a miracle. The genetics of rabbit hair color are very compliated. The genetics of the white rabbit with BLUE eyes is even more complicated.
May 28, 2016

SCIENCE HELP
2.3.4,6 nope, think harder.
May 28, 2016

Math- Prob Stat
you test the outcomes over time, to see if the outcomes are within the confidence intervals of the theoritical probability. And, one has to define fair.
May 28, 2016

Calculus
d^2=(12t)^2 + (19t)^2 where t is time in hours sailing. In this case, t=1hr take the derivative 2d dd/dt=2*144t+2*19^2 t dd/dt = relative velocity v= (288 +261)/d where d=sqrt(12^2+19^2)
May 28, 2016

Calculus
d^2=(12t)^2 + (19t)^2 where t is time in hours sailing. In this case, t=1hr solve for d.
May 28, 2016

SCIENCE PLZZ HELP!!!
strong base has very few H3O+ ions
May 28, 2016

Physics
The simple answer is yes, it is going 20k mph. However, that is a simple answer.
May 28, 2016

Physics
velocity has to be relative to something. What was the planet moving at 10Kmph relative to? Was it moving? What was the rocket relative to?
May 28, 2016

Mathematics
w=ax+bx^2+c 169=5a+25b+c 18=3a+9b+c So, assume c=0 first find a and b. multiply first equation by 3, second by 5 169*3=15a+75b 90=15a+45b subtract second equation from first 507-90=30b b=13.9 then find a in the second equation then, go to the original statement, check it with ...
May 28, 2016

business math
http://www.calculatorsoup.com/calculators/financial/depreciation-declining-balance.php
May 28, 2016

Physics
Pressure is the same, and the area of the output is proportional to the ratio of diamenters squared, so output force=(16/4)^2 *170N = 16*170N
May 28, 2016

physical science
Hydrogen bonding has a great effect on cohesive forces on molecules.
May 28, 2016

Maths
the tile has to be evenly divisible into 11.2 and 7.2 area=11.2*7.2=80.64 I see that .2 will go in both evenly. tiles .2x.2= .04 area number tiles=80.64/.04
May 28, 2016

Physics
mass=density*volume=density*area*t thickness=mass/density*area = 6.20E-6kg/(19.300kg/m^3*(2.98cm^2)(m/100cm)^2 = 6.20E-6/(19.300*2.98E-4) m =1.08mm check my work, that seems pretty thick .
May 28, 2016

PHYSICS
100=distance kicked+distance ran 100=48*cos37*t+v*t but t is time in air. hf=hi+vi*t -16t^2 0=0+48sin37 t-16t^2 0=t(48sin37-16t) t=4sin37 so put that t into the distance equation, solve for v. One wonders why your teacher is not using SI units.
May 28, 2016

Math pronto please help mrs sue
and you are wrong on both. Why don't you just multiply it out?
May 27, 2016

Probability
incorrect. Pr(2dimes)=2/8*1/7=2/56=1/23 In reality, because the coins are very different in size, they are not equal probability to draw out.
May 27, 2016

Physics
current=2.91sin30=.. speed of boat across 2.91cos30
May 27, 2016

Chemistry
yes, draw them out, and name them. Stick to alkanes.
May 27, 2016

Chemistry
Depends on the temperature of the solution. At zero C, .455g of lead bromide can be dissolved in 100g water. At 100C, about ten times that can be dissolved.
May 27, 2016

English
no, I think not. Cyclopes, giants, and louts are hardly civilized. All are strong...
May 27, 2016

U.S. History
Thoreau supported in writing John Brown in has violent actions at Harpers Ferry, which was hardly peaceful. In his essay Civil Disobedience, I find zero references to only peaceful resistance...but references to any means necessary. One should read the essay itself. Thoreau ...
May 27, 2016

U.S. History
Well, on 6 I disagree. However, others might agree. There has been in my lifetime a change in the connotation of the word "civil". However, in my understanding of Thoreau, "civil" does not mean peaceful, it meant government. You can do your own reading of ...
May 27, 2016

Chemistry
fast is a physical entity, it can be measured.
May 27, 2016

MATH ANSWER HELP
I think you are answer grazing. Lets try this: you give your explaination, and I will comment.
May 27, 2016

math
.06*Cost=75 Cost=75/.06=not 1175
May 27, 2016

Matt
outside surface=PI*D*L = PI*3.2cm*5.6cm
May 26, 2016

Math
x=.3*80
May 26, 2016

Physics
This is not physics, it is algebra I. 1/rt=1/r1+1/r2 common denominator on right is r1r2 1/rt=r1r2/r1r2 (1/r1+1/r2) 1/rt=(r2+r1)/r1r2 multiply both sides by rt*r1r2/(r1+r2) r1r2/(r1+r2)=rt
May 26, 2016

English
Raise is better. Lift implies something attached is raising.
May 26, 2016

physics
Henry
May 26, 2016

physic
force*distance=pressure*area*distance= 2.40E5Pa*PI( .0125)^2*.3 = ?
May 26, 2016

Math please help pronto
what is your thinking? z^a * z^b= z^(a+b)
May 26, 2016

Math-Calc
take the derivative... 2(x^2+y^2+2xy)=25(x^2-y^2) 2(2x dx + 2ydy+2ydx+2xdy=25(2xdx-2ydy) collect the dy terms dy(4y+2x-50y)=dx(-4x-2y+50x) dy/dx= you do it, then put in the point 3,1 and solve for dy/dx
May 26, 2016

Mrs.Sue?
Balance=2975(1.04)^t after t is what? Put this into your google search engine, with whatever t is supposed to be. 2975(1.04)^t=
May 26, 2016

Math topic part 2
b = .8a- .2
May 26, 2016

physics
work=600*4=2400joules power=2400/3 =800 watts
May 26, 2016

physics
vf=vi+at solve for a.
May 26, 2016

Algebra Plz help :)
I have no idea what the question is, and I have no idea what link you were following nor why. Please repeat the entire question. Thanks.
May 26, 2016

Quick physics help
http://www.theguardian.com/notesandqueries/query/0,5753,-19877,00.html
May 25, 2016

math
A+B=90 x+6+3x-8=90 4x=92 x=23 A=29 B=61
May 25, 2016

Math(PleaseHelp!)
proof. a+b = sum of even numbers 2(a/2)+2(b/2)= where a/2 and b/2 can be even or odd, or both. 2 ((a/2+b/2) ) has to be an even number, because it is evenly divislble by 2 (note the leading 2). Therefore, the sum of two even numbers is even.
May 25, 2016

Math
B, D
May 25, 2016

Math
If the base of the tower is on the same horizontal plane as the point 2m below P, then (h-2)/15= tan65 h=2+15tan65
May 25, 2016

mathh help plsss plsss
can be solved by factoring. ?? I wonder if your teacher meant "can have real roots". All can be factored, however, if the (b^2-4ac) is negative, the roots are complex, and Difficult to factor, however, they can be solved by factoring. b^2-4ac 36-34...=4
May 25, 2016

Algebra
(x-19)(x+1)....k=18 (5x+7)^2 k=70 (25x+7)(x+7) k=181, or (25x-7)(x-7) k=-181 (5x+49)(5x+1) k=150 or -150 (25x+49)(x+1) k=74 or -74 (25x+1)(x+49) k=1275 or -1275
May 25, 2016

CHEMISTRY
.4? That is very acid, very, very acid. Color depends on the specific indicator, but commonly, it will be very red. http://www.gcsescience.com/Indicator-Color-pH-Scale.gif
May 24, 2016

Algebra
slope of the line: m=(-3-1)/(4+1)=-4/5 slope of the perpendicular (gradient)=5/4
May 24, 2016

science
sinTheta=n/1.03 n/1.03=.994 n= 1.028 http://www.physicsclassroom.com/class/refrn/Lesson-3/The-Critical-Angle
May 24, 2016

calculus-help.. .Me
y=e^(-kt)[Acosh(qt)+Bsinh(qt)] y'=-ke^-kt [Acosh(qt)+Bsinh(qt)] +e^-kt[Aqsinh(qt)+Bqcosh(qt) y"=k^2 e^-kt[Acosh(qt)+Bsinh(qt)] -ke^-kt[Aq^2cosh(qt)+Bq^2sinh(qt)]-k^2e^-kt[Aqsinh(qt)+Bqcosh(qt)+e^-kt[Aq^2cosh(qt)+Bq^2sinh(qt) regrouping y'=(q^2-k^2)y-k^2(y')=0
May 24, 2016

Pre-Calc
cot2x+csc2x= cos2x/sin2x + 1/sin2x= [(1-sin2x)+1]/sin2x [2-sin2x]/sin2x 2csc2x-1= and done
May 24, 2016

Math
x=y^3+y well, you can use the method of http://www.ms.uky.edu/~corso/teaching/math330/Cardano.pdf
May 24, 2016

Physics
hf=hi+vi*t-4.8t^2 4.8t^2-22t-30=0 use the quadratic equation to solve for time t.
May 24, 2016

science
half-life, means statistically, the random events of disintegration half will have occurred on the average in that time. Half life only works when there are many, many particles: when 12 are involved, one cannot predict when six will have disintegrated. The model fails on ...
May 24, 2016

Math
scale factor; 1331/85184 =1:64
May 23, 2016

Math
I am not certain I am understanding. If I have it, it went 70km in 3hours speed=70/3=23 km/hr
May 23, 2016

astronomy
Nope. .83=e^(-.693*t/5730) take ln of each side. ln(.83)=-.693t/5730 t= -5730*ln(.83)/.693=1541years which is about 400 years different than the first answer.
May 23, 2016

Chemistry help asap
Alkaline buffer solutions An alkaline buffer solution has a pH greater than 7. Alkaline buffer solutions are commonly made from a weak base and one of its salts. A frequently used example is a mixture of ammonia solution and ammonium chloride solution. If these were mixed in ...
May 23, 2016

MATH PLZ HELP
An number cube is rolled 360 times and the results are recorded as follows:61 ones 26 twos 36 threes 76 fours 73 fives and 88 sixes what is the experimental probability of rolling a 2 or a 3 A. 0.07 B. 0.17 C. 0.26 D. 0.83 I DONT UNDERSTAND THIS ONE! Pr(exp)=Pr(2)+Pr(3)=(26+36...
May 23, 2016

Science - 6th grade
well, you ignored the air resistance during his forward motion (as he jumps out of the plane). It slows him.
May 23, 2016

Math
it also could be f(x)=- x^2 The data is not complete enought to make a decision on the function
May 23, 2016

Math
looks to me: f(x)=x-2
May 23, 2016

Physics
what happened to vo? it was 6.1m/s, not zero.
May 23, 2016

Math (Vectors)
theta=arcTan(7.2/5.7) and since it is in the third quadrant, theta=arctan(7.2/5.7) + 180 degrees
May 23, 2016

Geometry
Euler's Formula For any polyhedron that doesn't intersect itself, the Number of Faces plus the Number of Vertices (corner points) minus the Number of Edges always equals 2 Faces=Edges-Vertices+2 = 24-15+2=11
May 23, 2016

Algebra Please help me :(
The theoretical probabiliyt for any of the events is 1/2*1/2=1/4 the experimental probability for any trial is the number of successes divided by the trials. Example: TT(50) = 18/50=9/25=.36 Dont forget each outcome is random...
May 23, 2016

Physics
Pressure=80m* 1.03*9.8 kPa+101.3kpa now in terms of atmosphers, divide that all by 101.3kpa
May 22, 2016

Physics
pressure=h*1.2*9.8 kpa set that equal to 345kpa, solve for h in meters
May 22, 2016

Math
73 and 37
May 22, 2016

Algebra
.02*66+.08*Va=.04(Va+66) solving for Va Va(.08-.04)=66(.04-.02) Va=66(.02)/.04=33 liters so your chart should be... 66 - 0.02 - 1.32 x - 0.08 - .08x 66+x - 0.04 -2.64+.04x Your x is my Vacid Va I am not certain why your teacher is using these charts, most students get lost in ...
May 22, 2016

Algebra
Ta-940=Tb Ta+Tb=1540 subtract the first equation from the second. Tb+940=1540-Tb 2Tb=600 Tb=300 which implies Ta=1240feet
May 22, 2016

Math (pre-celc 12)
2x(x-30)(x^2-1) how did you get that from the previous line? Not possible. 2x^4-62x^2+60x Ok, looking for roots. by inspection, x=0, x=1 are roots so, I see 5 as a root, and finally, -6 (2x(x+6)(x-5)(x-1))
May 22, 2016

Physics
I assume that is gauge pressure, not absolute. weight of a column of water h high with diameter of 1m^2: weight=h*1*1E3kg/m^3*9.8N/kg pressure from that (weight /area) pressure=h*1E3*9.8 N/m^2=9.8h kPa 252kPa=9.8 kPa * h h=252/9.8 meters
May 22, 2016

Pharm
750ml/1.5hr= rateperhour
May 22, 2016

Chemistry
2HNO3+Mg(OH)2>>Mg(NO3)2 + 2 H2O so you need 1/2 mole magnesium hydroxide for each mole of nitric acid. MoleNitricAcid=.385*2.5*(molmassNitricacid) = .385*2.5*63 MassMg(OH)2=above/2 * molmassMgOH2 = above/2 * 58.3 grams
May 22, 2016

cfgcfhbcncf
volume=flowrate*area*time 50*44*.7 m^3=5000m/hr*PI (.7/2)^2 *time solve for time time=50*44*.7/(5000*PI*(.7/2)^2) hr
May 22, 2016

math
less than three is a one, or two. pr=1/2 * 1/6 + 1/2 * 1/6= 1/6 or is a word that indicates add the probabilities of each.
May 21, 2016

Math
ok, the three rectangles run at x=1, 2, 3 for the left endponits, at y=x^.5 the width is 1, so the area is 1*x^.5 areas: first 1-2, area=1*1^.5 left endpoint second 2-3, area=1*2^.5 third 3-4, area=1*3^.5 so the sum of areas is 1+sqrt2 + sqrt3
May 21, 2016

Physics
weight car=pressure*area*4tires pressure=1350*9.8/(.15*.13*4)Pascals now if you want to change from pascals to psi, pressurePascals*0.000145 psi
May 21, 2016

Chemistry
well, which is more? 2*5/4 ? 16/32 10/4 ? .5 2.5>.5 so H2 is far in excess.
May 21, 2016

chemistry
actually, no. M(OH)2 it means you have two hydroxide ions, consisting of 2 O atoms, and 2 H atoms, which are bonded as OH- in a covalent bond, a rather strong bond.
May 21, 2016

Hisyory
I have one comment on Mr Moore's blog on Aristotle, and it is in reference to <<Students sometimes use the theories and equations without understanding how they were developed, their limitations, or even what problems they address. The development of an idea from ...
May 21, 2016

ordinary differential equation
see solution 3 http://www.math.cmu.edu/~doffner/teaching/122/quiz7sol.pdf
May 21, 2016

mathematics
100=45+85-both both=30 which means biology only is 85-30
May 21, 2016

chemistry
CO2+Na2CO3 + H2O>>2NaHCO3
May 21, 2016

Science
an answer key. Or a magic 8 ball. or the I Ching.
May 21, 2016

math
well,then cotX=-3/4 or cotx-1 which means X=arcTan(-4/3) is in quad II or IV = 90+53.13, or 360-53.13 deg if cotx=1, then tanx=1, so x is in quad I or III x=45deg,or 180+45deg
May 21, 2016

math - analytic geometry
see other post
May 21, 2016

analytic geometry
http://www.purplemath.com/modules/ellipse.htm if the distances from the two foci are constant, then it is an ellipse, center at 0,0, Consider the point on the x axis x=5, the sum of distances to the foci is 10, so a=5, c=3, and b=sqrt(a^2-c^2)=4, so now you have all the ...
May 21, 2016

Pharmacy (Specific gravity of mixtures)
you want this basic algebra equation (first change pint to 483ml) 483ml*1.20+V*1.20+500*1=(V+483+500)1.15 solve for V of additional ml of glycol. V(1.20-1 )=1.15(983)-1.2(483)-500 V=I get 254ml check that.
May 20, 2016

BOB PURSLEY PLEASE HELP
Fq=.55*sinTheta Fg=.55*cosTheta first q: F=kqq/r^2=... http://hyperphysics.phy-astr.gsu.edu/hbase/electric/elefor.html
May 20, 2016

math
b is definitely wrong.
May 20, 2016

Global Communicaiton Studies
Psychology Wiki On the Wiki Wiki Activity Random page Videos Images TopContent community Contribute Watchlist Random page Recent changes Sociocultural factors 34,200pages on this wiki Edit Talk0 Assessment | Biopsychology | Comparative | Cognitive | Developmental | Language...
May 20, 2016

MATH REPOST
quadrant II
May 20, 2016

math
3/4 * 3 1/2= 3/4 * 7/2= 21/8= 2 5/8 Cups
May 20, 2016

chem.
Assuming NaI is the limiting reactant, so mass of PbI2 .. moles NaI=.7*.240=0.168moles, which means .168*2 moles of PbI2, so convert that to mass. mass=.168*2*(461) grams.
May 20, 2016

Physics
lAW OF INERTIA: An clark which is not in motion, will stay not in motion until a force acts on it. the train moved, clark did not. Claudette moved also, right underneath Clark.
May 20, 2016

pre algebra
I assume white means negative x^2-2x+3x-4+1= x^2+x-3
May 20, 2016

physics
A and C. Pythagorean theorem
May 20, 2016

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