Sunday
April 26, 2015

Posts by bobpursley


Total # Posts: 37,874

Math 222
you have to use grouping symbols. Did you mean this (x-3)/x^2 + 5x + 6/x + x/4 + 8 ?
April 26, 2015

Calculus 2
nth root of x is x^1/n nth root of (n-1)^n is n-1, is it not?
April 26, 2015

computers
3,10,17, 24, ... 3+n*7....3+51*7
April 26, 2015

physics
http://web.mit.edu/8.02T/www/802TEAL3D/visualizations/coursenotes/modules/guide05.pdf
April 26, 2015

Precalcus
look up the half-life of C14 1=10e^(-.693 t/thalf) solve for t Hint. Take Ln of each side.
April 25, 2015

Physics
change 100km/hr to m/s vf=at=Force/mass * t vf=mu*mg/m *t=mu*g*t solve for t b. d=1/2 a t^2 c. power=energy/time = (force*distance)/time=mu*mg*d/time now notice d/time is avg velocity=vf/2 This all ignores rolling friction, or kinetic
April 25, 2015

geometry
I suspect angle B is a right angle. Is that true? If so, then both legs are equal, a=c=4 hypotenuse then is 4sqrt2 Remember, hypotenuse^2 = leg1^2 + leg2^2 If this is not a right triangle, there is no way to solve it.
April 25, 2015

math
L=3+2W Now, for the box, L=originalL-4=3+2originalW-4 W=originalW-4 volume=LW*2 120=(3+2originalW-4)(originalW-4)*2 let me now use for originalW, w' 60=(2w'-1)(w'-4) 60=2w'^2-8w'-w'+4 56=2w'^2-9w' 2w'^2-9w'-56=0 (2w+7)(w'-8)=0 w'...
April 25, 2015

algebra
5sqrt6 -6+2*6 6+5sqrt6
April 25, 2015

government
getting voters to vote for her.
April 25, 2015

Science-Physics
vf=gt 4.3=9.8*t solve for time t.
April 25, 2015

physics
What is the question?
April 25, 2015

Chemistry
Molarity=moles/liter Now from the density, since you know water has a density of 1.00, then .06g/ml must be acetic acid. In a liter, then, 60grams/liter Molarity=60g/liter*MolmassAceticAcid = 60g/60.05g/mole= 1Molar
April 25, 2015

Science
I dont know what the man on the tread mill has done. work=m*g*height=750kg*9.8N/kg*.5m = 750*9.8*.5 joules
April 25, 2015

Physics
changein length=L*coeff*deltTemp = 1m*16E-6*50=800E-6m=.0008m length of rod now is 1.0008 m
April 25, 2015

phyiscs
Refers use more energy than they pump out of the air inside.
April 25, 2015

physical
If the relative density is 4.2 compared to water, then in water it will weigh the same amount less the weight of the water displaced. Example: if the volume is 1m^3, with RD 4.2, then its weight is 4200N. In water, its apparent weigh is 4200N-1m^3*1E3kg*9.8= 4200-980=3400N I ...
April 25, 2015

maths
Cost=2*(24+P)+3*2*P 368=48 +2P + 6P 8P=368-48=320 P=40 dollars for each pouch. Goodneess, Natalie needs to shop at KMart.
April 25, 2015

math geography and business studies
Most anything.
April 25, 2015

CHEMISTRY
I bet those answers are in your text, they are standard fare.
April 25, 2015

phy113
and the question is?
April 25, 2015

Physics Capacitance
Think of this. Replace all three capacitors with a new capicator of some value that is equal to the total combined circuit capacitance of x,y,z . Then the current vs time flowing thru the new capacitor is exaclty the same that has flowed thru X..which means the charge stored ...
April 25, 2015

Physics
Isn't there a standard formula for this? https://www.google.com/search?q=doppler+formula&ie=utf-8&oe=utf-8
April 25, 2015

Math
It doesn't take much to figure this one out... In probability theory, the central limit theorem (CLT) states that, given certain conditions, the arithmetic mean of a sufficiently large number of iterates of independent random variables, each with a well-defined expected ...
April 24, 2015

math
add all the scores
April 23, 2015

physics
or, the easier way... energybullelt=workinput 1/2 mass*80^2=avgforce*1meter solve for avgforce
April 23, 2015

physics
how high up? 200J=massbullet*g*heightinmeters speed? 200=1/2 massbullet*velocity^2
April 23, 2015

math
45=R+W 5R+3W=185 Are you certain on the getting 3 marks for every wrong answer? That is an odd way of scoring a math quiz. R=45-W 5(45-W)+3W=185 225-5W+3W=185 -2W=-40 W=20
April 23, 2015

math
14+0D=8+2D 2D=6 D=3
April 23, 2015

Math
what is 16/5280 ?
April 23, 2015

physics
I dont understand your work. 1/di+1/d0=1/f 1/di+1/60=1/15 1/di=3/60 di=20cm check that.
April 23, 2015

physics
force=Eq look at direction first, E is to the right (E is the direction a + test charge will do, you are adding a neg charge), so the force will be to the left
April 23, 2015

Math
P(1,then 10) = 4/(16) * (5/15)= 1/4*1/3=1/12
April 22, 2015

Chemistry
1000j=Hf*mass where Hf is the heat of fusion for water.
April 22, 2015

Pre-Calculus
one way to find your errors is this. Check each line with the same value of x, lets do it with x=0 3x + 15/x^2-25 + 4x^2 -1/ 2x^2 + 9x -5 VALUE: 15/-25 +1/5= -2/5 3(x+5)/(x+5)(x-5) + 4x^2 -1/ (x+5)(2x-1) Value: 15/-25 + 1/5: -2/5 6x^2+27x-15/(x+5)(x-5)(2x-1) + 2x^2 - 9x -5 ...
April 22, 2015

Physics
the sum of heats gained is zero. Heat gained = mass*c*(Tf-Ti) Heatgainedcopper+heatgainedwater=0 90*ccopper*(Tf-80)+270*cwater*(Tf-20)=0 solve for Tf
April 22, 2015

Math
tangent is 8/15 I am assuming C is the right angle.
April 22, 2015

Chemistry
write and balance the equation. C6H12O6+6O2>>>6CO2 + 6H20 check that so how many moles is 90 grams of glucose? You get six times as many moles of Carbon dioxide. Now the volume in liters depends on temperature and pressure.
April 22, 2015

Math
It won't happen in zero distance. Not possible. Something will move, even if it is Earth.
April 22, 2015

science
photons.
April 22, 2015

Chemistry
What reaction?
April 20, 2015

Physical science
The pressure (force/area) is the same in the system. F1/A1=F2/A2 F2=F1*A2/A1=1200N*.090/3.0=400*.09=36N
April 20, 2015

Chemistry
The mole ratio is 1:1, so figure the moles of potasium nutrite in 536g. Then figure the number of grams in that same number of moles of postassium nitrate.
April 20, 2015

Chemistry
25kg of HNO3? How many moles of HNO3 is that...figure it. Then, the mole ratio tells that you want 3/2 (1.5 x) as many moles of NO2, convert that to grams.
April 20, 2015

chemistry
Mass=volume*molarity*molmass = .1*.1*249.6 grans
April 20, 2015

PHYSICS
How high does the block go on the long track, no friction. Initial KE= mgH= 1/2 m vo^2=mg H H= 1/2 *g*vo^2
April 20, 2015

Physics
Without the figure....
April 19, 2015

Physics
the figure....
April 19, 2015

physics
friction=mu*Forcehorizonal Now, I wonder what is the purpose of the block? To hold the door shut? or just keep the block from falling. If this is a falling issue. 200=mu*force solve for force.
April 19, 2015

Physics
P*deltaV= external work -work internal 1.7atm*104cm^3=-work done internally+70J 101.3E3*1.7*104E-6 J-70J=-work done internally work internal=-.1013*1.7*104*6+70J = -17.9+70=52.1 J check that.
April 19, 2015

chem
well, K K=(a)(b)/(2C)^2 from the equation A, and B will be half the C concentration.. K= .75^2/4 / 1.50^2 now you have K. If C=.75, then A and B both used up .75/2 Which means the original-used is the now concentration A=1M-.75= you do it B=1.4M-.75= you do it in the above, ...
April 19, 2015

Physics
Huh?
April 18, 2015

physics
The sum of heats gained is zero. Heat gained=mcDeltaT 400*calum*(28-18)+200*cwater*(28-18)+MassNi*Cni*(28-80)=0 solve for MassNi
April 18, 2015

physics
heat=sum of Mal*Cal*deltaT+Mfe*Cfe*DeltaT remember Mal+Mfe=5kg you have two equations, two unknowns.
April 18, 2015

Physics
add the heat to heat the ice to 0C Then the heat to melt the ice at 0C then to heat the water from 0C t0 100C then to convert the water to steam at 100C then to heat the steam from 100C to 131C add them all up.
April 18, 2015

Physics
It is wrong. figure a. heat to heat ice to 0C from -11.5 Note: there is no reason to conver to K. One kelvin change is exactly one C change. Then heat to melt the ice at 0C then to heat the water from 0 C to 52 C add them up.
April 18, 2015

science-chemistry
101 g
April 18, 2015

physics
two down and one up.
April 18, 2015

physics
assuming he is mostly water, heat= 110*cwater*2 but heat also = masswaterevap*Lv set them equal, and solve.
April 18, 2015

ENGLISH
Slaughter of what? Anyway, you need to come up with 3-5 points to support this, and a discussion of each. You may want to find one or two of the opposing points, and make a SHORT contra discussion of those.
April 18, 2015

Physics
Not sure? one gains heat, one loses heat (a negative gain), so the sum of the heats gained is zero. HeatGainedLiquid+HeatGainedGlassss=0 m(cliq)(43-59)+m(cglass)(83-59)=0 solve for c of liquid.
April 18, 2015

mathematics teaching
Hmmmm. Wondering what is the difference? Is this a class from the looking glass?
April 18, 2015

chemistry
molarity=moles/volume= (molenitric+molesnitric)/volume = (3*.025 + 4*.075)/.100
April 18, 2015

math
see your previous post. There is no point to posting multiple times.
April 17, 2015

type of reaction
This is a synthesis, or combination reaction.
April 17, 2015

math
perimeter=2(150+50)=400m number laps=1000/400 so he has to do three laps.
April 17, 2015

PRE - CALCULUS
Your inequality is correct. I have no idea what meaning of the rest is. Think on a graph x,y, quadrant 1. all the area inside the triangle boardered by x axis, y axis, and the line 8x+7y=335, the region inside is not an allowable solution. On the line, and outside the triangle...
April 17, 2015

math
N-15=N/6 solve for N multiply both sides by 6 then add 90 to each side. Then suktract N from each side Then divide each side by 5
April 17, 2015

math
Hard to read. 3/4 * V=1/4(1.024 + V) is what I read. solve for V Then length^3=V or length= cuberoot (V)
April 17, 2015

Chemistry
first off, the ice was colder than OC. Adding salt lowers the freezing point of the "water". But it so the heat from the ice cream mixture melted some of the ice, making more salt solution in the outer bag. But melting that ice requires heat, so heat was taken from ...
April 17, 2015

law
you need to do a quick look at the 4th and 13th amendments to the US Constitution. Is it reasonable to stop every young black male? Is it offering all the equal protection of the law? Those are the constitutional questions.
April 17, 2015

Math
lets see..sum of one leg and hypotensues is 35 25^2+L^2=H^2 but 35=L+H or H=35-L 625=(35-L)^2-L^2 solve for L
April 17, 2015

physics
The bullet has a KE of 1/2 *.0973*666^2 joules. Now the energy released by the explosion is much more...hot gases, gases expanding, sound, fireball, and the energy in kickback.
April 17, 2015

physics
I will be happy to critique your solution, I am not about to do it and allow you to copy it.
April 17, 2015

physics
a. correct b. "finite age" needs to be pondered. you are assuming that time duration is the same for all observers, this is not so. If we could see the edge of the universe, we would see time zero. But at that time zero location, it is not time zero, that was 11 ...
April 17, 2015

physics
You can start out with conservation of monentum in x, y directions. That will give you two equations, two unknowns (both puck speeds after the collision) You should be able to solve it with those two equations. And,you have the conservation of energy equation if you need a ...
April 17, 2015

physics
Cannot be answered, unless you assume the max current produces 100W. When choosing resistors, that is an unwise decision. But assuming the unwise choice, the resistance of the resistor is P=v^2/R R= 50^2/100=25 ohm current initial= 2 amps I(t)=2e^(-T/RC) than find magnetic ...
April 17, 2015

physics
Your teacher made this very simple. Notice that the momentum of each is the same, which means the final momentum will be along the angle bisector of the oriainal angle separation. So each is 115/2 off that final path. final momentum=2*75*5.60*cos(115/5)=2*75* V solve for V
April 17, 2015

chemistry
No, on the second one, you need four sig digits..
April 16, 2015

Calc2
http://www.classzone.com/eservices/home/pdf/student/LA211DBD.pdf
April 16, 2015

chemistry
rule: O is -2, making V+4
April 16, 2015

Physics
You cannot assume elastic equation. But you do have conservation of momentum in two directions (x, and y). in x direction 1100v*cosTheta=1100*20Cos25+1400*23cos50 In the y direction 1100v*sinTheta=1100*20sin25 -1400*23sin50 You are looking for v. so, in the y equation solve ...
April 16, 2015

Chemistry
heat=mass*specificheatcapacity*changeinTemp heat=90*c*(100C-0C) look up the value of specific heat c, and you have it.
April 16, 2015

Science
c is the best answer, but it is not good. What is missing is how does energy become mass, and mass become energy in a chemical reaction.
April 16, 2015

science
distance=1/2 acceleration*time^2 or time= sqrt (2*distance/acceleration)
April 16, 2015

Science
figure out the mass of the mercury.. mass=volumemercury/densitymercury. then the moles of mercury.. molesHg=massHg/molmassHg then you want the same moles of al molesAl=molesHg=massHg/molmassHg then volume al=massAl/densityAl=molesAl*molmassAl/densitAl So if I can put all that ...
April 16, 2015

physics please help
ignoring air resistance, vf^2=2gh 2. with a terminal velocity of 30m/s final KE=1/2 m 30^2 3. work done by fricion= mgh-1/2 m (30^2) 4. average force by air resistance over the entire flight.. avgforce*h= work done by friction
April 16, 2015

Math
yes, it is possible (but not often done). No, the intersection does not have to be at 0,0
April 15, 2015

physics
d=Asin(2PIf)t v= 2PIf*A cos(2PIft) you are given A, and v, and A, solve for f. a= (2PIf)^2 A sin(2PIft) now solve for acceleration a
April 15, 2015

math
your question is nuts. "The value ..of independent variable...the value of the independent value." So it has to be C, but I suspect the question as you typed it is wrong.
April 15, 2015

math
amount=80+.15*200=80+30
April 15, 2015

Science
most light shades diffuse the light as is passes thru. None of the answers indicate that, a very poor question. The proper answer is diffuse transmission.
April 15, 2015

Science
freezing and thawing are mechanical processes which crack rock.
April 15, 2015

Physics
The mass of the turntable is not trivial, and probably more important for motor and drive design. However, Thin disk moment of inertia= 1/2 m r^2 rotational energy gained= 1/2 I w^2 w=33.3*2PI*60 energy total= 1/2 (m *.304^2)(33.3*2PI*60)^2 you know m, and PI, compute in joules
April 15, 2015

6th Grade Science Experiment
independent is one you can manipulate, or change. Dependent is the result. example how much water you drink during the day, independent. how many times you run to the bathroom: dependent.
April 15, 2015

Physics
see other post.
April 15, 2015

Physics
yes, it is wrong. That would be the speed of the center of mass, but it is rotating, so the tip speed would be twice that.
April 15, 2015

Algebra
This is confusing, however, I think you want angle-n*360-given where angle is less than 360 example: 1. 1*360-370=-10deg 2*360-370=350 deg 3. 2PI-5PI/2=-1/2 PI 2*2PI-5PI/2= 1/5PI
April 14, 2015

Physic
What is 1.5E11/avagradrosNumber * 22 grams
April 14, 2015

physics
avg velocity= total distance/total time = (vo*t+ v2*t2+v1*t1)/(t+t2+t1)
April 14, 2015

  1. Pages:
  2. 1
  3. 2
  4. 3
  5. 4
  6. 5
  7. 6
  8. 7
  9. 8
  10. 9
  11. 10
  12. 11
  13. 12
  14. 13
  15. 14
  16. 15
  17. Next>>

Members