Monday
December 22, 2014

Posts by kb


Total # Posts: 46

chemistry
How many joules of energy would be liberated by condensing 49.6 mol of steam at 100.0 °C and allowing the liquid to cool to 30.0 °C?
November 15, 2014

physics
the mass of the water is 131 kg and its initial temperature is 24.2°C, how much energy must the water transfer to its surroundings in order to freeze completely? The specific heat of water is 4186 J/kg·K, and the latent heat of fusion is 333 kJ/kg
August 5, 2014

physics
When a water gun is fired while being held horizontally at a height of 1.14 m above ground level, the water travels a horizontal distance of 4.50 m. A child, holding the same gun in a horizontal position, slides down a 34.0◦ incline at a con- stant speed of 1.98 m/...
January 14, 2014

IT
You have been tasked with the project of organizing a company offsite 2-day training session in which people are brought in from different parts of the country. This entails everything from preparation, accommodations, and facilities. • There is APA style paper using APA ...
July 17, 2013

Chemistry
Thanks!
March 11, 2013

Chemistry
I'm not sure how to set up the equations using the volumes, and I'm not even sure what givens I'm supposed to use.
March 11, 2013

Chemistry
Calculate the pH for each of the following points in the titration of 50.0 mL of a 2.7 M H3PO3(aq) with 2.7 M KOH(aq). pKa1 = 1.3 and pKa2 = 6.7 a) before addition of any KOH b) after addition of 25.0 mL of KOH c) after addition of 50.0 mL of KOH d) after addition of 75.0 mL ...
March 11, 2013

Chemistry
Oh... I see where I went wrong. thanks!
March 11, 2013

Chemistry
Ok, that's what I did before. so 2E-11 = x^2/(0.1-x) so x^2 = 2E-12 - 2E-11x But what I don't understand then is how do we solve for x? I used the quadratic equation but when I plugged in those values it gives me 0. So where am I going wrong?
March 11, 2013

Chemistry
I'm really confused. I've never done a problem like this before. Could you plug in the values for me? It just doesn't make any sense and my teacher won't explain it to me when I ask about it.
March 11, 2013

Chemistry
But what's Kw? and the value for NH3? Is that just x? So should it be Kw/5.0x10-4 =(x)(x)/(0.1-x)
March 11, 2013

Chemistry
Calculate the pH at the equivalence point for the titration of 0.200 M methylamine (CH3NH2) with 0.200 M HCl. The Kb of methylamine is 5.0× 10–4.
March 11, 2013

government
. The source of the Supreme Court’s authority is (Points : 1) moral suasion. judicial activism. concurring opinion. dissent.
February 26, 2013

PHYSICS
bob is correct, except that you have to subtract the Force*sin(31). It's a poorly worded problem, to say the least.
October 11, 2012

calculus
suppose the set of points have the following coordinates:(-2,3),(4,-4),(2,-3). please calculate the moment of this set of points about the x-axis and also about the center.
August 17, 2012

math
need help with "you have $15 in your bank account. you spend $11 on a hat. then you mow 3 lawns for $20 each and deposit the money into your bank account, write and solve an expression (using order of operations) to determine how much money is in your account." I ...
January 5, 2012

Math- Linear Equations
suppose a new watersports company aqua sports is open for business they are running a grand opening sale their rental cost can be modeled by linear equation we are told that for 30 minutes of use their rental cost will $50 for 60 minutes of use their rental cost will be$80 ...
October 19, 2011

chemistry
A mixture of carbon and sulphur has a mass of 9.0 g. Complete combustion with excess oxygen gives 22.6 g of a mixture of carbon dioxide and sulphur dioxide. Find the mass of sulphur in the original mixture
September 22, 2011

biology
(Which of the following would least likely induce thirst) a)Dry pharynx b)Decrease blood volume c)decrease blood pressure d)decreased blood osmolarity
July 22, 2011

biology
lipid soluble must be oxidized before they are excreted from.otherwise the toxins would not be able to pass through the a)bowman capsule b)red blood cells c)cell membranes d)cytoskeleton
July 22, 2011

chemistry
find the maximum value of h2(g)in grams that would be expected to form by reacting 6.54g of zinc with 50ml of 0.1M of HCl.
July 22, 2011

chemistry
what is the angular momentum quantum number for the orbital from which an Mg atom loses two electrons to form Mg2+ ion.
July 20, 2011

physics II
the lens to retina distance in the human eye averages 2.0cm what is the power of the lens of the human eye
July 20, 2011

physics
alpha particles are accelerated through a potential of 1000volts and then enter a magnetic field 0.2T perpendicular to the their direction of motion.Calculate the radius of the circular path that they traverse.An alpha particle has a mass 6.68x 10^-27kg and a charge of +2e.
April 6, 2011

physics
11. The charged plates of a parallel plate capacitor each have a charge density of 3 x 10-3 C/m2. What is the electric field E between the plates?
March 15, 2011

Physics
The space between two points
February 22, 2011

physics
a supertanker with a mass of 5.0 x 10 to the 8th power kg accelerates from rest to a speed of 10 m/s in a time of 1000s. what is its average acceleration? how much force is required to accelerate the supertanker?
October 4, 2010

Physics
Chris Cheggies
September 23, 2009

chemistry
If you heated a hydrate too quickly and some of it splattered out of the beaker how would it affect the calclated percent by mass of water and the molecular formula
September 6, 2009

math
i have a math question and i know that there is a simple solution that i am missing. We are going to be given a 100 foot piece of rope and we have to make a baseball diamond where the bases are 60feet apart. Help
August 31, 2009

physics
An airplane is flying horizontally with a constant velocity of 160 m/s at an altitude of 5400 m when it drops a package. How far ahead of the target along the x direction should the plane be when it releases the package?
February 25, 2009

Algebra
The first three equations I have solved, I would just appreciate someone checking them over to make sure I'm doing them right. Find the GCF: 16x^2z ,40xz^2 , 72z^3 = 3^3z Factor our GCF: a(a+1) - 3(a+1) = a+1 Factor Polynomial: 9a^2 - 64b^2 = (3a+8b)(3a-8b) 9w - w^3 = w(3...
January 22, 2009

physics
PV=nRT ideal gas law is the only thing i got n R T will stay constant i believe so that leaves me with PV so PV of initial vs. PV of final... maybe
November 19, 2008

physics
just guessing but normal atmospheric pressure
November 19, 2008

physics
A primitive diving bell consists of a cylindrical tank with one end open and one end closed. The tank is lowered into a freshwater lake, open end downward. Water rises into the tank, compressing the trapped air, whose temperature remains constant during the descent. The tank ...
November 19, 2008

physics
When you take a bath, how many kilograms of hot water (48°C) must you mix with cold water (13°C) so that the temperature of the bath is 36°C? The total mass of water (hot plus cold) is 185 kg. Ignore any heat flow between the water and its external surroundings.
November 17, 2008

PHYSICS
A molecule consists of two atoms. The atoms have masses of 17 u and 14 u and are 1.78e-10 m apart. How far from the first atom is the center of mass of the molecule?
October 14, 2008

Math
1.367
October 14, 2008

physics
A mine car, whose mass is 590 kg, rolls at a speed of 0.5 m/s on a horizontal track, as the drawing shows. A 150 kg chunk of coal has a speed of 0.95 m/s when it leaves the chute. Determine the velocity of the car/coal system after the coal has come to rest in the car.
October 14, 2008

physics
thank you
October 14, 2008

physics
A 45 kg skater is standing still in front of a wall. By pushing against the wall she propels herself backward with a velocity of -1.0 m/s. Her hands are in contact with the wall for 0.80 s. Ignore friction and wind resistance. Find the magnitude and direction of the average ...
October 14, 2008

geometry
A rope is connected to a boat and to the boat's anchor that is resting on the ocean floor at a position not directly under the boat. The rope is 105 feet long and the water is 55 feet deep. To the nearest tenth of a foot, how far is the anchor from a point directly below ...
October 2, 2008

algebra 1
it equals a negative number
October 2, 2008

geometry
A rope is connected to a boat and to the boat's anchor that is resting on the ocean floor at a position not directly under the boat. The rope is 105 feet long and the water is 55 feet deep. To the nearest tenth of a foot, how far is the anchor from a point directly below ...
October 2, 2008

algebra
solve for x: 2(x-3) - 3(x+5) = 3 (x-2) - 7 Perform the indicated multiplications; add up the constants and the terms that involve x; then get all terms that involve x on one side of the equation. 2x -6 -3x -15 = 3x -6 -7 -x -21 = 3x -13 -8 = 4x x = ? -2
July 10, 2007

algebra
A homeowner wishes to insulate her attic with fiberglass insulation to conserve energy. The insulation comes in 40-cm wide rolls that are cut to fit between the rafters in the attic. If the roof is 6 m from peak to eave and the attic space is 2 m high at the peak, how long ...
July 4, 2007

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