Wednesday
September 17, 2014

Posts by bobpursley


Total # Posts: 35,988

Science
Seems to me it is output of a decision process.
September 16, 2014

college algebra
L(L-1)=342 L^2-L-342=0 (L-19)(L+18)=0 L=19, w=18
September 16, 2014

college algebra
23^2=(x)^2 + (x+7)^2 x is the base distance. solve for x.
September 16, 2014

physics
Tension=weigh+ma 33.8=4.69(g+a) solve for a, upwards if +, if negative, downward)
September 16, 2014

World History Answer Check--Help me!
The first answer is brief, but pretty much correct. Righteousness in itself is worthy of a longer answer. The second question is very biased. What makes you certain Islam is the correct term? Are your meaning Quran, or Shara Law instead of Islam? What makes this question to me...
September 16, 2014

Physics
Tan 55=height/radius Circumf=2PI Radius or radius=34/2PI height= 34/2PI * tan 55
September 15, 2014

chemistry
you did not add the heat given off during cooling from 100C to 0C
September 15, 2014

Physics Need Help
potential energy at start=Kenergy at end mgh=1/2 m v^2 h= 1/2 v^2/g
September 14, 2014

Physics Help Urgent
The acceleration is constant, which means the ball is slowing down with time at a constant rate. velocity-time graph velocity starts at some V, then decreases linearly to zero (at the top), and continues down on the same line as it descends. it ends at v=-12m/s. position time...
September 14, 2014

Physics
avg speed=distance/time time for a lap=1.600/250 hr=.0064 hr time for the first half lap=.800/225= .0035555 hr time for second half lap= .0064-.0035555= .0028445 avg speed on second half= .8/.0028445 km/hr This certainly is a small track for such high speeds.
September 14, 2014

physics
power=Voltage*current=14E3*2.3E-3 watts
September 13, 2014

Physics
energy= power*timeinsecond=1220*60*1.3 Joules cost=1.22Kw*1.3/60 hr * 12.1 cents/kwhr
September 13, 2014

physics
what is the relationship of A and B?
September 13, 2014

Physics
KE=workbraking 1/2 m v^2=mu*mg*distance solve for mu.
September 13, 2014

HISTORY
first is correct. Second. rice was native to Western Hemisphere. Wheat and Bananas were not. Tobacco is native to the Western Hemisphere. cats are not a plant.
September 13, 2014

Physics
time in air: vf=vi-gt=42-9.8t in the vertical , vf=-vi t= 2*42/9.8=84/9.8 figure that out. horizontal distance=vh*time vhoriz=211/time above Looks right.
September 13, 2014

Science
a= change in velocity/time
September 13, 2014

math
four-sevenths http://www.grammarbook.com/numbers/numbers.asp
September 13, 2014

physics
1ft=.3048m 1cubic ft= (.3048)^3 meters^3 so in meters cubed, the volume= 3.70*6076ft * 2.8*6076ft * 26*6ft * (.3076)^3 m^3/ft^3
September 13, 2014

chemestry
what is a gg?
September 13, 2014

physics
see other post
September 13, 2014

Chemistry
Cu + Cl2>>CuCl2 + 220.1kJ/mole
September 13, 2014

law
They have the same rights as others, however, some may be limited due to employment (right to sue the chief), or restricted by the constitutional rights of those they arrest (they cannot listen to an arrestee unless he has been warned of their 4th admendment rights). They ...
September 13, 2014

Goverment
Texas is the one of the state that has the right to divide into up to five new states, each with Senators. That is different. This was agreed to when the Republic of Texas was admitted to the Union. In a compromise designed to overcome objections to annexation, the 1845 joint ...
September 12, 2014

Algebra
find x for when A=0 it is a quadratic, you get two values of x. Because the maximum is half way between these two minimums, (it is a parabola), then the max is at the sum of the roots divided by 2. put that average x into the formula, and you have the max value.
September 12, 2014

CHEMISTRY
http://misterguch.brinkster.net/q10.html
September 12, 2014

Science (college level)
Wien's displacement law Lamdamax*temp=b where λmax is the peak wavelength, T is the absolute temperature of the black body, and b is a constant of proportionality called Wien's displacement constant, equal to 2.8977721(26)×10−3 m K.[1] Watch your ...
September 12, 2014

physics
avg speed=distance/time=617/105 Direction is S, and N is positive, however, speed does not include any direction notation. avgspeed=617/105 m/s
September 12, 2014

Physics
total acceleration^2=centacc^2 + tangentialacc^2 solve for centripetal acceleration then v^r/r=centripacc solve for v. Now for later, wf^2=wi^2+2 alpha*displacement alpha*r=tangential acceleration, displacement=1/8 *2PI vf^2/r^2=v^2/r^2 + 12/r * 1/8 *2PI solve for Vf
September 12, 2014

math
is there a question here?
September 11, 2014

physics
Is there a question here?
September 11, 2014

math
d=r1*t+r2*t job=job/13 hrs*timetotal1+job/15*timetotal2 but time total2=2 hrs time total1 is what is to be determined 1=1/15* 2 + 1/13 * (t-2) where t is the time after the two hours left. 13*15=26+ 15t-30 15t=13*15-4 t= 12.7333 hrs check my thinking
September 11, 2014

physics
during the run: vf^2=vi^2 + 2ad solve for vf but vf= ai*t solve for time t. so sqrt (2ad)=ai*t square both side 2ad=a^2 t^2 t= sqrt (2d/a)
September 11, 2014

Chemistry please help
balance the reaction equation. C2H4+3O2>>>2CO2 + 2H2O if one assumes temp and pressure remain constant, then the law of volumes indicates one gets two volumes of carbon dioxide for each volume of ethene. So ...208ml volume of O2 remaining, you used 3*104ml, so ...
September 11, 2014

3
this makes no sense.
September 11, 2014

3
So the path was 5.79ms further? so the distance half that? d=velocity light*time
September 11, 2014

physics
horrizontal distance=vi*cosTheta*time vi*costheta=12/.650 now, for time in the air hf=hi+1/2 g t^2+ vi*sinTheta*t 2.8= -4.9 t^2+vi*sinTheta*t you know t, for vi put in 12/(cosTheta*.65) 2.8= -4.9 t^2+ sinTheta*t*12/(cosTheta*.65) now you have an equation you can solve for Tan ...
September 11, 2014

Physics 1
at ???
September 11, 2014

math
Because you have to add place values...
September 10, 2014

Chemistry
I will be happy to critique your work. Read the statements, it tells you what the limiting reactant should be in any case.
September 10, 2014

algebra
wouldn't abs(.357) be the least?
September 10, 2014

Algebra
if it is a negative number, then it goes from -2.78 to +2.78
September 10, 2014

Physical Science
change km/hr to m/s KE=1/2 m v^2 it took that much work to give it that much KE Same amount
September 10, 2014

Physic
and then?
September 10, 2014

Chemistry
didn't the most outer energy level become depleted, and the net force on the electrons become stronger stronger in the absence of two outer electrons?
September 10, 2014

math
start with... x^2+8x+8=0 then x^2+8x+8+8=8 x^2+8x+16=8 (x+4)^2=(2sqrt2)^2 x+4=+-2sqrt2 x= -4 +2sqrt2, and x=-4 -2sqrt 2 (x+4-2sqrt2)(x+4+2sqrt2)
September 10, 2014

math
didn't I just do this? http://www.jiskha.com/display.cgi?id=1410350888
September 10, 2014

engineering science
break the 44 N force into components up the slope, and normal to the slope. F=44cos17.5 u + 44sin17.5 n now break the weight in to normal, and up the slope components. 60N down= 60cos17.5 n - 60 sin17.5 u frictional force opposes upward, so it is a negative force up the slope...
September 10, 2014

math
x^2+8x+8? it has no factor until it equals something. Do you mean x^2+8x+8=0? then x^2+8x+8+8=8 x^2+8x+16=8 (x+4)^2=(2sqrt2)^2 x+4=+-2sqrt2 x= -4 +2sqrt2, and x=-4 -2sqrt 2 (x+4-2sqrt2)(x+4+2sqrt2)
September 10, 2014

College Physics
I am wondering if the tank axis is horizontal, or vertical?
September 10, 2014

math
This term "retardations".... It has units of velocity. Velocity is not a "retardation", see Newtons first law of motion. I do not know what you are asking.
September 10, 2014

physics
work done=weight of water into tank*20m power= work done/time power=1/.65 * 300m^3*densitywater*g*20m/(5hr*3600sec/hr)
September 10, 2014

physics
didn't air replace the juice, and that air is at atmopsheric pressure?
September 10, 2014

physics
displacement=34kmN+ 99*cos32 N + 99*sin32E combine the first two terms, you will have total displacement.
September 9, 2014

Physics
b. consider a mirror: if it were a light beam, wouldn't tilting it more make the light beam go further horizontal? c. whatever the gain in velocity coming down before hitting the ramp, the same force reduces it going up. Range, remains the same.
September 9, 2014

physics
velociy=110/5.1 m/s acceleration= (0-110/5.1 )/4.3 m/s^2
September 9, 2014

Physics
force=G m1 m2/distance^2
September 9, 2014

physics
ok, when they meet. finalpositionB=x =vB*time final poistionA=x+DB=vA*time+DB setting these final positions equal vA*time+DB=vB*time time=DB/(vB-Va)
September 9, 2014

math - please help
-1<=x<=5 f(x)=-2x domain: from -1 to 5
September 9, 2014

calculus
I cannot determine exactly your first term. Put the quadratic in this form ax^2+bx<=200 then ax^2+bx-200<=0 then solve the left side x=(-b+-sqrt(b^2-4ac)/2a
September 9, 2014

Physics
Yes, to get the same pressure on the tank, total area has to be 1000x. area is proportional to diameter squared. A=PI/4 (D^2)... so if the diameters were 20 cm, then the new diameters should be 20sqrt(1000)
September 9, 2014

physics
distance. separation. It is not parallax.
September 9, 2014

phycis
time to fall: 1969=1/2 g t^2 t= sqrt(2*1980/g) now, horizontal distance traveled during that time t AB= 600km/hr*t(inseconds)*1/3600 in meters.
September 9, 2014

History
Add elevation, it gets colder. Snow forms on mountain tops. The went to lowlands to avoid the cold. Many animals do the same. Birds go to lowlands, or South.
September 8, 2014

physics
you have to know something more. Is there a magnetic field involved? what is its strength?
September 8, 2014

Physics
see related questions below
September 7, 2014

Physics
at the starting point, t is very small. If A is ahead, then A-B must be negative. A-B=αt+βt^2-γt^2+δt^3. For very small t, the first term will predominate. A is ahead. When is A-B=0? 2.6t+1.2t^2-2.8t^2+.2t^3=0 combine the t^2 terms. then factor out a t, you...
September 7, 2014

physics
find the velocity of the first car at 4.4 seconds. AT that point, both have the same starting point, one is accelerating, one is const velocity. When they meet again, they have traveled the same distance. d1=vi*t+1/2 a t^2 d2=68.1*t d1=d2, set them equal, solve for time.
September 7, 2014

Ed. Tech
yes, A
September 7, 2014

physics
distance=avgvelocity*total time
September 7, 2014

Physics
force gravity=force elec mg=kqq/r^2 solve for r.
September 7, 2014

Physics
Tension in the spring = (1/2)k*x^2 For equilibrium, 9*10^9*Q^2/(0.5 + x)^2 = (1/2)k*x^2 that is your error. Tension in the spsring is kx and for equilibrium, kx=9*10^9*Q^2/(0.5 + x)^2
September 7, 2014

chemistry
one amu is equal to 1/12 mass C12 nuclues one amu is 1.66E-27 kg
September 7, 2014

chemistry
see the other post, multiply 1 amu in kg by 278, then multipy it by 1000 to convert to grams.
September 7, 2014

Calculus-Math
f'=1/2 ln(x^6) + 1/2 x/x^6 * 6x^5 put in x=-1, f' is the slope of the graph at x=-1,0 tangent line: y=mx + b 0=f'(-1,0) * -1 + b solve for b then y=f'(-1,0) x + b is the equation
September 7, 2014

Physics
energy density= 1/2 epsilion abs(E^2) 9 mm^3=9 (1m/E3 mm)^3=9E-9 m^3 energy density= 17/8E-9= 2.125E9 J/m^3 now solve for E
September 7, 2014

Math
what is 20/34 of 2? 20*2/34=30/17= 1 13/17 34:20::2: 1 13/17
September 7, 2014

8th grade math
3.14*1000= 3140
September 7, 2014

Physics
avg velocity= (finalvelocity+initialvel)/2 first, find the stop and start velocityies t(0) t(2.02) t(4.00) I will do one for you, the last one. avgvel=(v(4.00)+v(2.02))/2
September 7, 2014

Physics
momentum is conserved, energy is conserved in an elastic collision. first pendulum: m g h= at the bottom 1/2 m v^2 v= sqrt (2g*.75) that is velocity of m1 at the bottom. solve for v Now, the collision momentum: .065*v=.065v'+.085v2 energy: 1/2 .065v'^2=1/2 .065v'^2...
September 7, 2014

Physics
distance=avgvelocity*time
September 7, 2014

physics
assuming the target is horizontal from the gun. distance bullet falls: h=1/2 g t^2 where the time is from t=45.6/480 seconds so aim h above the target.
September 7, 2014

chemistry
amount of iron in product 37.9g*(2* 55.84/(2* 55.84+16*3)( how much Fe3O4 would this iron make? moles Fe= (massironabove/55.84) mole O= molesFe * 4/3 mass fe304=(2* moles Fe above+ 4 moles O above)* molemass Fe#O4) percent Fe3O4 in ore= massFe3O4/65.46
September 7, 2014

physics
it means to find true speed over ground, you have to add water velocity. Example, a river is going 10m/s North. You jump in the water, with zero relative speed...you will go with the current, speed over ground 10 N you swim upstream at 2m/s back to the dock, but the stream is ...
September 7, 2014

Chemistry (concentrations)
there are two Cl- for each magnesium chloride unit. 26.2 ppt for chloride ions
September 7, 2014

science
initial momentum=.5*25 kg m/s at halfway up, it has lost 1/2 of its energy. energy then=initial energy. 1/2 m v^2=1/2 *1/2 m 25^2 so v= .7*25 momentum then= .7 of initial momentum
September 7, 2014

Physics
add them. forcenet=F1 + F2 = -2.5*9/(.250+.7)^2 + 3.3*9/(.250+0)^2 put units on charges, I ignored that. Direction. think quickly, which force on q3 is greatest, the repulsive, or the attractive.
September 7, 2014

Physics
force=kqq/r^2 solve for q
September 7, 2014

Physics
1. find time toaccelerate vf=a t t= 9/1.5=6 seconds then find time to deaccelerate vf=vi+at 0=-vi/a +t t= 9/ 2= 4.5 seconds now the distance it went at constant velocity 400=1/2 (1.5)*6^2 + 9 tc +9/2 * 4.5 400=27+9tc+10.1 tc=(400-27-10.1)/9=40.3 second total time: 40.3+4.5+6 ...
September 6, 2014

Physics
v(t)=vi-9.8t d(t)=+vi*t-4.9t^2
September 6, 2014

algebra
solve it a number of ways, I will do determinates. Det=-18*7-36= -162 x= 70+92 / det= 162/-162=-1 y=-18*23+90 /det= -324/-162=2
September 4, 2014

chemistry
All at the same pressure and temperature? It matters. Now percentage by mass? Percentage by number molecule? I suppose you want precentage by mass, but am not certain. PercentN2= massN2/total mass So assume sTP, as long as all are the same temp pressure, it doesn't matter...
September 4, 2014

Exponential decay
amountleft=akmountoriginal (1/2)^t left/original= (1/2)^t taking the ln of each side ln(left/orig)=t ln(.5)=kt now take the antilog of each side left/orig=e^kt left=yo*e^kt so what is k? if left/yo=e^kt at 1/2= e^k*T ln of each side .693=kT k= .693/T so the equation is of the ...
September 4, 2014

writing
If you didn't catch it, that is my favorite, Lady Gaga. My daughters despise her.
September 4, 2014

writing
It depends on how much depth you want. Deep: compare the foreign policy of Hitler in 1938/39/40 to Putin in Georgia and Ukraine. Shallow: Compare Elizabeth Barrett's poem "How do I love thee?" with Shakespear"s sonnet 116. A puddle: Compare Lady Gage to ...
September 4, 2014

physics
hf=hi+vi'*t-4.9t^2 hf, hi =0 Vi'=25*sin30deg. solve for t.
September 4, 2014

science
Thus, the correct molecular weight of horse myoglobin is 16,951.49 and that of the sperm whale protein is 17,199.91 atomic mass units. So in grams, one multiplies that by the mass of 1/12 of a Carbon 12 atom, so the horse myoglobin=1.66053892E−27 *16,900= 455087.807=2....
September 4, 2014

physics
hf=hi+vi*t-4.9t^2 hf=0, hi=1.59, vi given, solve for time t in the air. how high? at the top, vf=0 vf^2=vi^2-2g*height solve for height.
September 4, 2014

Physics
4x or 160units
September 4, 2014

Physics
A: d=Va*t1-4.9t1^2 B: d=-Va*t2-4.9t2^2 set them equal -Va*t2-4.9t2^2=Va*t1-4.9t1^2 -Va(t1+t2)=4.9(t2^2-t1^2) -Va(t1+t2)=4.9 (t2-t1)(t2+t1) -Va=4.9(t2-t1) or t1-t2=Va/4.9
September 4, 2014

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