Friday

November 28, 2014

November 28, 2014

Total # Posts: 513

**chemistry**

.115 mol of solute is put in a container and water is added to give 250ml of solutrion. what is the molarity
*November 4, 2011*

**Calculus**

For question a), how did you get 12800? Where'd that come from?
*November 1, 2011*

**statistics**

What is the standard deviation of a normal distribution, whose mean is 35, in which an x-value of 23 has a z-score of -1.63?
*October 13, 2011*

**College Physics**

In this problem you will estimate the heat lost by a typical house, assuming that the temperature inside is T(in) = 20 degrees celcius and the temperature outside is T(out) = 0 degrees celcius. The walls have fiberglass insulation, which dominates the heat conduction ...
*October 8, 2011*

**College Physics**

The top layer of your goose down sleeping bag has a thickness of 5.0 cm and a surface area of 1.0 m^2. When the outside temperature is -18 degrees celcius you lose 24 Cal/hr by heat conduction through the bag (which remains at a cozy 34 degrees celcius inside). Assume that you...
*October 7, 2011*

**College Physics**

the answer is 0.027
*October 7, 2011*

**College Physics**

is k 0.023076923 ?
*October 7, 2011*

**College Physics**

The top layer of your goose down sleeping bag has a thickness of 5.0 cm and a surface area of 1.0 m^2. When the outside temperature is -18 degrees celcius you lose 24 Cal/hr by heat conduction through the bag (which remains at a cozy 34 degrees celcius inside). Assume that you...
*October 7, 2011*

**College Physics**

Nvm. I found the answer :) It's 555 W. (.200 W/m x K)(22m^2)[(19.3-16.4)/0.0230 m]
*October 7, 2011*

**College Physics**

A 2.30-cm-thick wood floor covers a 4.0 m x 5.5 m room. The subfloor on which the flooring sits is at a temperature of 16.4 degrees celcius, while the air in the room is at 19.3 degrees celcius. What is the rate of heat conduction through the floor? Use 0.200 W / m x K for the...
*October 7, 2011*

**Organic chemistry**

You are at isoelectric point for a solution of Leucine. If the number of negatively charged carboxyl ate groups, -COO-, is 1x10^19, how many positively charged amino groups, NH3+, would there be?
*October 5, 2011*

**college physics**

1 and 2 only :)
*October 4, 2011*

**Chemistry **

Why is the solubility of KHTar greater in a 0.10M NaNO3 solution than in distilled water?
*July 14, 2011*

**Spanish -9th grade-Please check and advise**

I figured it out. I could say "Normalmente tengo mucha tarea en la clase."
*May 16, 2011*

**Spanish -9th grade-Please check and advise**

I need to write about my geometry class and what I do in the class. I need to use "la tarea" in the sentence. I'm not sure if I could use this to describe the calculations I do. I'm confused how to even conjugate or use this. Would it start with "Hago la...
*May 16, 2011*

**math**

My mother and I are the same age – only the numbers are reversed (21,12 for example) Twelve years ago my mom was twice as old as me. So how old is my mommy and how old am I?
*May 9, 2011*

**technical math/precal**

18/3square roots of 6-7square roots of 2
*May 3, 2011*

**physical science**

The resultant vector of two particular displacement vectors dose not equal the sum of the magnitudes of the individual vectors. Describe the directions of the two vectors.
*May 2, 2011*

**science**

a person exerts 35 lbs of force to turn a door handle ( radius = 4 cm). How much force is exerted on the inner "axle" with a radius of 5 mm?
*May 1, 2011*

**Chemistry**

How do you calculate the heat fusion of ice? I have the initial and final temperatures and volume of the water.
*April 26, 2011*

**math**

4,200/120=
*April 26, 2011*

**Chemistry**

106 g of iron at 84.0°C are placed in contact with 205 g of silver at 11.0°C. If no heat is lost to the surroundings, what is the final temperature of the metals? The specific heat of iron is 0.418 J/g·°C and that of silver is 0.251 J/g·°C. 92.0 g...
*April 25, 2011*

**Statistics**

Discuss how a t Test can be employed in hypothesis testing by the use of directional vs. non directional hypotheses. Discuss types of research where using the t statistic may be an appropriate alternative to using a z-score.
*April 20, 2011*

**chemistry**

Fe2O3+ 3CO=2Fe+3Co2, suppose that 1.64kg of Fe are obtained from a 2.62kg sample of Fe2O3 (ore). assuming that the reaction goes to completion, what is the percent purity of the Fe2O3 in the original sample.
*April 19, 2011*

**CHEMISTRY**

Fe2O3 + 3CO= 2Fe + 3CO2, SUPPOSE THAT 1.64kg OF Fe ARE OBTAINED FROM A 2.62kg SAMPLE OF Fe2O3(ORE). ASSUMING THE REACTION IS COMPLETE, WHAT IS THE PERCENT PURITY OF THE Fe2O3 IN THE ORIGINAL SAMPLE?
*April 17, 2011*

**Physics**

A trapeze artist weighs 8.00 x 10^2 N. The artist momentarily held to one side of a swing by a partner so that both of the swing ropes are at an angle of 30º with the vertical. In such a condition of static equilibrium, what is the horizontal force being applied by the ...
*April 13, 2011*

**health**

Is there anyone that could possibly help me understand medical terminology? My college course has transitioned to an all online setting with in-class closed book exams. I'm having a hard time understanding the difference in word roots and combining forms. For instance: she...
*April 11, 2011*

**math**

Consider a party with 60 people. Assume each person knows more than m other people. How large must m be to guarantee that 3 people know each other?
*March 31, 2011*

**geometry**

The ratio of the areas of two similar trapezoids is 1:9. What is the ratio of the lengths of their altitudes?
*March 30, 2011*

**Physics**

I figured it out! PEg = gmh W = Fh PEg/W
*March 29, 2011*

**Physics**

A pulley system is used to lift a piano 2.6 m. If a force of 2510 is applied to the rope as the rope is pulled in 14 m, what is the efficiency of the machine? Assume the mass of the piano is 750 kg. I know the equation is eff = Wout / Win I'm just confused on what I'm ...
*March 29, 2011*

**Physics**

A 14,300 N car traveling at 46.0 km/h rounds a curve of radius 2.30 x 10^2 m. What is the minimum coefficient of static friction between the tires and the road that will allow the car to round the curve safely?
*March 29, 2011*

**Physics**

thank you sooo much!
*March 29, 2011*

**Physics**

Tarzan tries to cross a river by swinging from one bank to the other on a vine that is 10.2 m long. His speed at the bottom of the swing is 7.6 m/s. Tarzan does not know that the vine has a breaking strength of 1.0 103 N. What is the largest mass that Tarzan can have and still...
*March 29, 2011*

**Physics**

A satellite with an orbital period of exactly 24.0 h is always positioned over the same spot on Earth. This is known as a geosynchronous orbit. Television, communication, and weather satellites use geosynchronous orbits. At what distance would a satellite have to orbit Earth ...
*March 29, 2011*

**Physics**

A tennis player places a 58 kg ball machine on a frictionless surface, as shown below. The machine fires a 0.068 kg tennis ball horizontally with a velocity of 31.6 m/s toward the north. What is the final velocity of the machine? ______m/s to the south
*March 21, 2011*

**11 grade English**

In Swimming Strokes by Lee Carroll in paragraph 1, how many errors are there in subject-verb agreement, parallelism, and pronoun-antecedent agreement?
*March 21, 2011*

**Physics**

A 57.8 kg pole-vaulter falls from rest from a height of 5.4 m onto a foam-rubber pad. The pole-vaulter comes to rest 0.25 s after landing on the pad. (a) Calculate the athlete's velocity just before reaching the pad. ______ m/s downward (b) Calculate the constant force ...
*March 21, 2011*

**Physics**

An 95.0 kg astronaut is working on the engines of a spaceship that is drifting through space with a constant velocity. The astronaut turns away to look at Earth and several seconds later is 26.3 m behind the ship, at rest relative to the spaceship. The only way to return to ...
*March 21, 2011*

**physics**

µk x (m x g) x d x cos 30º 0.40 x (290 x 9.81) x 4.0 x cos 30º hopefully that works
*March 21, 2011*

**High School Chemistry**

10mL of 0.10M HCl is given. What is the pH? How many milliliters of 0.10M NaOH would be required to neutralize it? What is the pH of the neutralized solution? What would the pH of the solution be if you added 20mL of NaOH? Here's what I have so far: pH of HCl=-log(0.10M)= ...
*March 21, 2011*

**Newton' law of motion**

Force = mass x acceleration 50N=10kg x a
*March 9, 2011*

**Physics**

thank you.
*March 9, 2011*

**Physics**

A 50.0 kg diver steps off a diving board and drops straight down into the water. The net force when in the water is an upward 1450 N. If the diver comes to rest 5.0 m below the water's surface, what is the total distance between the diving board and the diver's ...
*March 9, 2011*

**physics**

A ^9 Be nucleus containing four protons and five neutrons has a mass of 1.50×10−26 kg and is traveling vertically upward at 1.70 km/s. If this particle suddenly enters a horizontal magnetic field of 1.25 T pointing from west to east, find the direction of its ...
*March 9, 2011*

**college prep math**

what is the least common denominator of (x-4/5x^2-14x-3)-(2x/10x^2-3x-1)+(7x-2/2x^2-7x+3)
*March 3, 2011*

**physics**

Four forces act on a hot-air balloon, F_1 is upward at 4600 N, F_2 is left at 1450 N, F_3 is right at 850 N, and F_4 is downward at 3600 N. ____ N at _____ degrees clockwise from F_2.
*February 22, 2011*

**physics**

A 2.32 kg book is dropped from a height of +3.7 m. a.) What is its acceleration? b.) What is its weight in newtons?
*February 22, 2011*

**physics**

a 2 kg rabbit starts from rest and is moving at 6 m/s after 3 seconds. What force must the rabbit cause to makes this change in speed?
*February 22, 2011*

**math**

If i paid 1.25 in sales tax for an item i purchased. the sales tax rate was 5%. What was the price of the item before tax
*February 15, 2011*

**physics**

How many joules of energy are required to run a 100 W light bulb for one day? Burning coal yields about 30x10 to the 8J of energy per kilogram of coal burned. Assuming that the coal power plant is 30% efficient, how much coal has to be burned to light the bulb for one day?
*February 2, 2011*

**geometry**

what is approximate area of triangle if each side is 36 inches long
*January 31, 2011*

**marketing**

ABC Technologies manufactures computer accessories, such as modems and network cards. Even though the company has several purchasing managers, the company president has final authority on all purchases over $500, including the selection of the supplier. In the typical buying ...
*January 30, 2011*

**Physics**

Thanks it worked :)
*January 2, 2011*

**Physics**

Im using the F=Gm1m2/r^2. So to figure out the y i plugged in the values for massA and B and used a radius of .5 to get 2.96E-7. For the x i used the same formula but did it twice once for particle CB and the other for BD. then i added them together and got -1.74E-7.
*January 2, 2011*

**Physics**

Four uniform spheres, with masses mA = 37 kg, mB = 30 kg, mC = 220 kg, and mD = 55 kg, have (x, y) coordinates of (0, 50 cm), (0, 0), (-77 cm, 0), and (44 cm, 0), respectively. Find the net force on sphere B due to the other spheres. What are the (a)x and (b)y components of ...
*January 2, 2011*

**Physics-Gravitation**

when i plugged in the values i got 4.62E10 is that number suppose to be negative or positive?
*January 2, 2011*

**physics**

A coin is placed on a vinyl stereo record that is making 78 revolutions per minute on a turntable. Find the magnitude of the acceleration when the coin is placed 5.0, 10, and 17 cm from the center of the record. The radius of Earth is about 6.38x10^3 km. A 7.40x10^3 N ...
*December 13, 2010*

**Math**

Give vertex, axis, x-intercepts and y-intercepts to parabola y= -3x^2-6x+4
*November 24, 2010*

**Chemistry**

I'm having a hard time with a question predicting the reaction (if any) of 1,2-dichloroethane and sodium iodide, sodium iodate, and sulfuric acid. Any suggestions? Thanks!
*November 16, 2010*

**Chemistry**

I'm having a hard time with a question predicting the reaction (if any) of 1,2-dichloroethane and sodium iodide, sodium iodate, and sulfuric acid. Any suggestions? Thanks!
*November 16, 2010*

**Physics**

Work = Force x distance Both traveled the same distance (flight of stairs) & both were composed of the same force (weight). Therefore, they both exerted the same amount of force. However, the first person who climbed the stairs at 30 s exerted more energy at less time than the...
*November 15, 2010*

**Mathematics **

Find the periodic payment that will amount to the given sum under the given conditions: S=$150,000; interest is 6% compounded semiannually; payments are made at the end of each semiannual period for 11 years
*November 7, 2010*

**chemistry**

Can someone please explain why there are so many gas laws. I've been doing my homework with the appropriate formulas, but I'm confused why everyone keeps say that PV=nRT is so wonderful? You can't get the same solution by using this ONE formula, so what is so ...
*November 7, 2010*

**Chemistry**

What is the molarity of 350 mL of solution that contains 27 g of CaCl2?
*November 5, 2010*

**Chemistry**

What is the mass of 1.665 x 10 to the 22nd formula units of calcium acetate,Ca(C2H3O2)2?
*November 5, 2010*

**Chemistry**

What is the molar mass of calcium acetate, Ca(C2H3O2)2?
*November 5, 2010*

**Chemistry**

What is the molarity of 350 mL of solution that contains 27 grams of CaCl2?
*November 5, 2010*

**American Government**

If the U.S. were to have another constitutional convention, would we keep a federal system or change it? why or why not?
*November 2, 2010*

**physics**

When we measure displacement, you measure the distance between the Initial Position (260) & the Final Position (175). Displacement = Difference between initial position & final position. Initial - Final = Displacement 260 - 175 = 85 m.
*October 22, 2010*

**physics**

A planet is 400 times more massive than the earth, and its radius is 10 times that of the earth. The weight of an object on the surface of the planet is?
*October 21, 2010*

**statistics**

Starting with the data values 70 and 100, add three data values to the sample so that the mean is 96, the median is 97, and the mode is 97
*October 15, 2010*

**physics**

A crate of mass 97 kg is loaded onto the back of a flatbed truck. The coefficient of static friction between the box and the truck bed is 0.26. What is the smallest radius of curvature (in m) that the truck can take, if the speed with which it is going around a circle is 44 m/...
*October 4, 2010*

**Math**

Of people who died in the US in recent years, 86% were white, 12% were black, and 2% were Asian. (This ignores a small number of deaths among other races.) Diabetes cause 2.8% of deaths among whites, 4.4% among blacks, and 3.5% among Asians. The probability that a randomly ...
*October 3, 2010*

**College Anatomy**

Where do bones increase in length? Where do bones increase in diameter?
*September 29, 2010*

**physics**

If the green ball bounces upward from the ground with a speed of 20 m/s (immediately after it hit the ground), calculate the momentum of the ball as it goes upward immediately after hitting the ground
*September 28, 2010*

**geometry**

If ef=2x+4,fg=4x-10,and eg=12 find the values of x,ef and fg?
*September 20, 2010*

**College Anatomy**

Chromosome
*September 11, 2010*

**College Anatomy**

What are linear structures formed from chromatin?
*September 11, 2010*

**College Anatomy**

What organelle produces spindle fibers during mitosis?
*September 11, 2010*

**College Anatomy**

Inclusions
*September 11, 2010*

**College Anatomy**

neuron and prokaryotic
*September 11, 2010*

**College Anatomy**

Which of the organelles in a cell is most directly related to organic evolution? Why?
*September 11, 2010*

**College Chemistry **

If you leave a glass of tap water out long enough, the water will evaporate and leave behind a white solid. Is this a chemical or physical change?
*September 10, 2010*

**College Chemistry **

A plant grows. Is that a chemical or physical change?
*September 10, 2010*

**College Chemistry **

Is this a physical or chemical change?
*September 10, 2010*

**College Chemistry **

If you leave a glass of tap water out long enough, the water will evaporate and leave behind a white solid.
*September 10, 2010*

**College Chemistry **

When you bake cake batter it solidifies. Is this a physical or chemical change?
*September 10, 2010*

**College Chemistry **

When two solutions are mixed, small bubbles are formed. Is that a chemical or physical change?
*September 10, 2010*

**College Chemistry **

Also something i forgot to add while posting this question. The 0 and 28 are in degrees Celsius and the ice cube tray which the water is held in has 925 grams of water
*September 8, 2010*

**College Chemistry **

If the water initially has a temperature of 28, how many kilojoules of heat must be removed to cool and freeze the water at 0?
*September 8, 2010*

**math**

evaluate. 8 1⁄4 - 6 15⁄32 i got 2 7/32 is this correct. if not what am i doing wrong.
*June 16, 2010*

**math**

Marco is making a scale drawing of a building. The scale for the drawing is 1 inch = 7 feet. The height of the building in the drawing is 1 foot. Determine the height of the actual building. Someone please help me.
*June 16, 2010*

**Math**

(7.66 • 10^2)(6.29 • 10^-4) answer then convert to scientific notation. the answer I keep getting is 0.481814 the scientific notation I get from this is 4.81814*10^5 but i keep getting it wrong. Can someone please help me.
*June 16, 2010*

**Math**

Multiply or divide and write scientific notation for the result. (7.66 • 10^2)(6.29 • 10^-4) can someone please help me with this.
*June 13, 2010*

**PreAlgebra**

Convert to decimal notation. 3.73 • 10^-4= -37300 Im not good with intergers. I just needed to know if this was correct. If not can someone explain it to me.
*June 13, 2010*

**PreAlgebra**

Convert to decimal notation. 5.585 • 10^6= 55,850,000 I need to know if this is correct? If not how do you do this? Thanks
*June 13, 2010*

**PreAlgebra**

Write an equivalent expression using negative exponents. 1/3^9 will i write this as 3^-9. please explain this to me.
*June 13, 2010*

**Math**

I have no clue what this means. Can someone explain this to me. Evaluate t^1
*June 12, 2010*

**Math**

Someone please help me. I have no clue where to start. 1. My family and I went to Applebee's for dinner. The price for the meal for all of us was $73.49. How much will a 15% tip be? What will be the total amount paid including tip? 2. My insurance commission rate is 12%. A...
*June 8, 2010*

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