# Posts by bobpursley

Total # Posts: 44,357

**history**

The were siblings for the most part, sometimes hugging, sometime advesaries, sometimes at war. Money and status were prime factors.

**Chemistry**

Where did you use lambda of 7E-7 m?

**physics**

E=k(3/d^2 +2/d^2) where d is the half distance E=k(5/d^2) now d=.01m so E=k(5E-4) N/C

**sociology**

A brief overview, but would need to be amplified n an intelligent discussion. https://www.boundless.com/sociology/textbooks/boundless-sociology-textbook/deviance-social-control-and-crime-7/theories-of-crime-and-deviance-61/sociological-theories-of-deviance-371-10205/ Not ...

**Math**

5 (3cd+b) = A(3cd+b) A = 5 Math - Hatsune Miku, Sunday, April 30, 2017 at 10:58am On the last thing which is 5 (3cd+b) = A(3cd+b), how did you get 5 as an answer? Can you teach me step by step? Sorry omg I'm so confused Math - Hatsune Miku, Sunday, April 30, 2017 at 11:...

**Science**

It probably won't be enough for the fare,she will ask for more. What are you thinking of?

**science**

I think you do not know what an open circulatory system is. Google: reptile circulatory system

**Social Studies**

What was the cause of the collapse of the Soviet Union? The causes of the fall of the Soviet Union were many and included ethnic conflict, a lack of support for the idea of communism and economic troubles caused by a focus on arms. Despite reform efforts by Mikhail Gorbachev, ...

**Advanced Functions**

x^2-2x-8 (x-4)(x+2)<=0 x<=4, x<=-2

**electrical**

you need the current requirements for that motor, then, use your cable charts to see what cable is safe for that current.

**Grade 12 Advanced Functions**

l=w=h+5 or h= l-5 500=Lwh= l^2(l-5) l^3-L^2-500=0 I would solve that graphically on your calculator, see were L satisfies the function...about 7.6cm

**physics help**

KE in the rotation= 1/2 *momnet*w^2 moment is given w=2PI*1100/60 rad/sec solve for KE

**physics help**

period? Time=distance/2PIr=39m/s /.34*PI= 2PIr/39m/s= .0548sec each rotation of 2PI occurs in that time, so in one second it angle= 2PI*1/.0548 radians

**Pre**

letters: usually do not use O. Let N be number of letters, ten the number of numerals. a) N*N*10^4 b) N*N*10!/(10-4)! c) N!/(N-2)! * 10!/(10-4)!

**Chemistry**

Answer A. The sign for the electron spin is arbitrary, as the spin axis is arbitrary, if based on anything, it is an external magnetic field. There is no difference in energy levels, or order of filling the +- 1/2 spins.

**Physics**

force=coulombs law= k qq/.028^2 you are given q, and I assume you know coulombs constant, if not look it up and memborize

**Math**

In geometry, an octahedron (plural: octahedra) is a polyhedron with eight faces, twelve edges, and six vertices. A regular octahedron is a Platonic solid composed of eight equilateral triangles, four of which meet at each vertex. A regular octahedron is the dual polyhedron of ...

**Social Studies help ASAP**

2.Which one D or C? C of course.

**Social Studies help ASAP**

4. Crime, gangs threatening business owners, and corruption were and are challenges. Which answer ties to that? Think. 3. I dunno, I recommend you reread the story. 1,2. both look ok to me.

**physics heat**

newtons law of cooling Tf=ti*e^k*time 40=60*e^k*7 ln 40/60 = 7k k= 1/7 * ln(2/3)=-0.058 Tf=40(e^(-.058*7)=26.6

**SCIENCE**

one would have to have an E force which opposed the weight to just enough to make friction eactly the same as the weight down the plane. weight down the plane mgsinTheta force of friction= mg*mu*cosTheta Now E must reduce weight enough to reduce friction, so force friction=...

**Precalculus -- Systems of Equations**

Well done, Scott.

**Geometry**

a) pr(3red, replacement)=(9/20)^3 b) pr(3red, wo replacement)=9/20 * 8/19*7/18

**phy**

a. wf=wi+alpha*t 5500*2PI= 9000*2PI+alpha*7.5 angular acceleratin=-(3500*2PI)/7.5 rad/sec^2 b. Torque: wf^2=wi^2+2*torque*displacement where displacement=avg speed*time = (9000+5500)*PI * 7.5 radians solve for torque

**electrical**

I have no idea what your text says happens.

**electrical**

see your text.

**Math**

totalamount=amounteach*numbershirts =3/4 * 15=45/4=12 yards.

**math**

what is 101kN/m^2 * .4m*.3m ?

**Algebra**

N2+m1=21 N+m=17 subtract second equation fromfirs N=4 M=13

**Chemistry**

proton: H+ di protic H2SO4, H2CO3 triprotic H3PO4 most ionize in steps https://en.wikipedia.org/wiki/Diprotic_acid

**physics**

water molecules move.

**science**

one-third of 24 joules PE=weight*height

**Please help with MATH**

Twice as fast mean Al will be back home (there and back) when Bill reaches Al's end (ie, they both get there at the same time. That is the second time they meet, the first was at 2/3 the way from Al to Bill's end.

**physics HELP!!**

http://hyperphysics.phy-astr.gsu.edu/hbase/electric/pplate.html C=epsilon*area/separation energy=1/2 C*V^2

**social studies**

B. determining who most needs them most turns out to be not so clear, and often depends on social values. And in politics, social values carry a lot of weight.

**Physics**

Your diagram is beyond understanding.

**Math (Physics)**

Hours? Ridiculous. resistance=resitivity*length/area area= PI (d/2)^2 you are given diameter d, 0.0011meter area= PI (.00055)^2=9.50e-7 can you handle it from here?

**Physics**

The force on each of particle has magnitude... no kidding. The force will be along the directions of the sides, due to symettry. Each of the two forces on a charge is kqq/.5^2 but we want only the compoent in the direction of the angle bisector, which is 30 deg from each side...

**fgh**

I agree, I often can't count past 10.

**fgh**

number: 9!/(5!4!) * 8!/(4!4!) * 3!/2!1! b. 7!/(5!2!)*7!/(4!3!)*3!/2!1! See the pattern?

**college physics HELP**

you know force (mg) and stretch. Find k. F=kx b. standard formula for period of a spring, period is 1/frequency. c. total energy: 1/2 k (initial stretch)^2 d. 1/2 m v^2 + 1/2 k (.15)^2=totalenegy, solve for v. e. acceleration=force/mass=kx/mass where x is the max stretch given...

**college physics HELP**

What is it that you are having difficultly with? This question is incredibly cookbook.

**science**

http://www.nationalgeographic.org/media/earths-fresh-water/ first paragraph

**physics**

conservation of momentum .3*10+.3*O=.6V solve for V

**buisness**

B. Jack gave John the disk for a day. John accepted it, and has promised to ride him back home.

**college algebra**

in Matrix form: 1,0,2 P5 3,-1,-1:12 6,-1,-5:27 so subtracting equation 2 from 3 we get equation 1, and 3,0,-4:15 Now multiply equation 1 by a factor of 2 to get 2,0,4:10 now adding those two equations 5,0,0:25 orx=5 putting that into equation 1, we get z=0 putting those into ...

**Technology and Society**

release of personal identification.

**education**

http://www.mass.gov/eohhs/docs/dcf/c-fp-ap-guide.pdf https://www.acf.hhs.gov/cb/laws-policies You have to cautious on this: Foster care is the domain of States, not the federal government, nor cities.

**Math- Please help**

see level 2 prob six on page 15 on this document: http://math.fau.edu/MathematicsCompetition/spring2000/spring2000solution.pdf

**alg 2 cotangent**

sure: what is the angle whose cotan is 1? what is the angle whose cot is sqrt3?

**algebra**

x can be any real number.

**Math**

correct.

**math**

The probability of winning is 1 38 so the odds are one in thirty-eight

**2 math questions, urgent plz help!!**

a, correct b, slope is 1, or tan Theta=1 (tanTheta)=y/x

**ALG II COT**

which cotangent formula?

**algebra HELP PLEEEEASE**

y = x^2 - 2x - 6 y = 4x + 10 subtract the second equation from the first: 0=x^2-6x-16 then factor (x-8)*(x+2)=0 x=8, or x=-2

**English**

Are you certain you have the right line numbers? In 586-87 it is another example (following several) comparing Satan's victories over mortals, specifically Charlemain. I don't see a connection with the earlier lines in which Satan was justifying the greatness of Hell.

**geomeotry PLEASEE HELPPPPPPp!**

each of the base sides is 7.5cm if it is regular. The perimeter of a lateral face less the base is 20cm So the perimeter of the edges on the faces is 40 cm, plus the base perimeter, total perimeter is 70cm

**Pls help urgent math**

Length of cable=L 2L/7 +L/5+L/3+(443*3+1)/3=L Multiply by 35*3 2*15L+21L+35L+35*(443*3+1)=35*3L L(35*3-30-21-35)=443*3 +1 solve for L

**PHYSICS**

wf=wi+2(angular acceleration)*angle 0=(30^2PI)^2+ 2*alpha*163*2PI solve for alpha, angular acceleration. Then Torque=alpha*momentinertia solve for torque

**World History**

Stalin's primary objective was to rebuild the Russia, and the occupied (conquered in Stalin's mind), at the expense of Germany. In Berlin, the main asset in the eyes of the occupying Russian troops were the Germany women (and girls), and they raped over 100,000 of them...

**reliabiility**

The ratio of true score variance to the observed score variance: 40/50 = 0.80

**Science**

calculate the moles of each gas (mass/molmass), add them up to get the total moles of gases: For each gas, mole fraction=molesthatgas/totalmoles then partial pressure= molefraction*total pressure

**Math and science for young children**

Understand? ages 7 and 8 kids can understand "past" and " in the future" meanings. But all kids develope differently. Read this: (Never get a young child a digital watch..) http://www.parents.com/advice/toddlers-preschoolers/development/when-will-my-child-...

**Trig/Pre-Calc**

draw the vector triangle (head to tail). I have on my sketch 30 at 30deg SofE, and then on its head a vector of 10 pointing SW. The angle (check this) between the two vectors is (30+45) degrees Law of cosines> R^2=10^2+30^2 - 2*10*30*cos75 solve for the resultant R

**Chemistry**

Exactly what is a mile of gas? Do you mean moles? PV=nRT P=nRT/V put

**Physics**

I dont understand the angle of inclined plane: is that to the vertical or horizontal?

**Chemistry**

correct. Think about bond strength.

**physic**

you know KE initial, you know final KE is .86 of that. Solve for Vfinal from that. Force= mass (Vi+vf)/time notice the vf is added (it is a minus for the change in direction, so minus a minus is +

**Math**

12*8*height=576 height= 576/(96)

**chem**

I don't quite understand this reaction; PCl3(g)<==>POCl(g) + Cl2(g)

**phy 101**

N: 7cos40 E: 7sin30+10 determine the values of those two. Resultant^2=N^2 + E^2

**science**

Explain in detail what causes tides was this details?????? http://oceanservice.noaa.gov/education/kits/tides/tides02_cause.html

**Physics (Waves)**

assume the incoming light is coming an at an angle theta to the first filter, and assume it is not circular polarization. light getting through I*costheta now the light getting thru the second filter is I*cosTheta*cos(theta+45) now if I remember my trig identities that equals ...

**Physics (Waves)**

Light getting thru: .33=cos(Theta) theta= arc cos(.33) Now that is assuming the incident E plane is situated such that the first filter is aligned with it.

**physics (please help I have a test tmrw)**

you use the right relations. heat=.5kg(cwater)(50)+.5kg*Lv make certain you use cwater in kJ/kg, and Lv in kJ/kg

**Physics pls help**

If they stick together 4*6-2*4=(6)V solve for v Loss of KE=1/2 6 v^2-1/2 4*6^2-1/2 2 *16 Impluses: mass*change velocity 4(6-V) and the second one 2(-4-V)

**physics**

heat=massglass*specificheatglass* (32-5)

**Physics**

Nope

**chemistry**

Thanks. Do you have a question about this?

**physics**

if the first harmonic is 272, then the fundamental is half that, 136hz lambad/2=.56 wavelength=1.12 m Freq*lambda = speed thinking: 100*1=100m/s, or about 1/3 the speed of sound in air, which is odd, as the speed of sound in a wire should be much more. So, how does that work: ...

**AP physics**

and what is your question?

**Science 8.4**

look at your periodic table. Groups are vertical. For instance, the second Na,S,Al,Cl is not a group. Then for the groups shown, the least protons will be a the top of the group, and going down increasing in protons.

**finite math**

pr=4/52 * 3/51 b)= 4/52 * 4/52

**Physics**

As a very general rule the maximum speed of any displacement hull--commonly called its hull speed--is governed by a simple formula: hull speed in knots equals 1.34 times the square root of the waterline length in feet (HS = 1.34 x ?LWL).

**Physics**

you have the right formula, change g/m to kg/m 1.2g/m=.0012 v=sqrt(9/.0012)= about 86m/s

**physics**

I cant do the sketch. Notice the E is in directions, which the vertical will cancel out, and you are left with a net horzontal (to the axis of symettry) component. Given that, a full circle would then cancel that out, and E at the center would be zero. Now, all that is true in...

**physics**

double the length, double the surface area, so charge density is halved. add another 10nC to bring the sigma back up to original.

**Chemistry**

heat=2*125*Cw*(23.25-22.45) Now that is the heat for .010*1mole of each reactant, or .020*1mole of NaCl (check this on balanced reaction). so if you want to get heat per mole of NaCl, then divide heat above by .020

**Physics 1401**

force down:2*9.8 force up: 1*9.8 Net force= forcedown-forceup=ma solve for a: mass=3kg (9.8)(2-1)=3*a a= 9.8/3 tension= mass*g-+mass*acceleration tensionheavy side= 2(g-g/3)=4g/3 tensionlight side=1g+1g/3=4g/3

**Math**

None are very good. the second and third are right in some instances. for instance a) 3.4E-2= .0034 the second answer is right b) 4.7E2= 4700 the third answer is right. So if you take the - sign in the exponet to meaning "not right", as in move the the NOT right 2 ...

**chemistry**

mass is balanced on each side, as well as electrons. Each Cu ion has to receive two electrons, and each Al atom donate three 2Al(s) + 3Cu 2+(aq) <====> 3Cu(s) + 2Al3+ (aq) so, six electrons were donated, and six received, and the mass is the same on each side.

**maths (probability)**

Again, you are not going to be able to graze for answers here. We will help, but we are not going to... This is your second notice. If you have a specific issue, or question, ask. But don't post your homework expecting others to do if for you.

**MATHS PLEASE HELP ME**

Come on, this is your complete set with no thinking. I wlll do two, and you can do the other five and we will check them. 7) ways = 6!/(2!4!) times (5!/(2!4!) times (4!/1!3!) simplified ways=5*3*5*2*4= 15*40=600 check that. On a soccer team three fullbacks can play any of the ...

**Chemistry**

Isn't lead sulfide not soluble? I will be happy to critique your thinking.

**phyiscs**

wouldn't that depend on the spring? 2PI/period=sqrt(k/m) k/m= (2PI/5)^2 force=kx x=force/k= mg/k= 9.8*(5/2PI)^2 check that.

**math**

slope is less than 4? then arctan<4 or the angle is less than 1.328 radians.

**Physics**

I dont understand your question on where you are having difficulty. Is there something specific you don't understand on these questions?

**Calculus**

a) 2(y^2-2)=6 solve for y. y^2-2=6 y= +-sqrt8, x=2 b) y^2+2yy'x-2xy-y'x^2=0 y'(2xy-x^2)=2xy-y^2 y'= you finish it. c. slope=y', put in the two points in a), and calculate

**Physics**

figure the mass of the wood: .12*.12*.06*600kg== 0.000864(600)= = 0.5184 kg so now, the volume of water displaced must be 518cm 12*12*h=518 solve for h in cm