Wednesday

September 17, 2014

September 17, 2014

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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