Monday

July 28, 2014

July 28, 2014

Total # Posts: 964

**chem**

In a vehicle, H2 could be used in a fuel cell to generate energy. Hydrogen is not an energy source, but a means of transporting energy because the extraction of H2 from the logical source, H2O, takes as much energy as is returned when the gas is used. 2 H2O (l) → 2 H2 (g...

**physics**

an object is initially moving 15.0 m/s. a minute later, it is moving 25.0 m/s in the opposite direction. What is the displacement and acceleration?

**Math Help Please**

x=4.4

**chem 101**

using the unit conversion method derive an equation to calculate heat produced from the HCl-Na OH reaction

**6th grade**

What are the two similar features for long shore current and rip currents?

**chem 101**

how many grams of oxalic acid dihydrate to completely neutralize 25ml of 0.12 M of sodium hydroxide

**physics**

the string off of A

**physics**

no its on a flat surface with the static friction of .25. and W is hanging off the string at a 45 degree angle vertically.

**physics**

(a)block A weigh 60N. the coefficient of static friction between the block and the surface on which it rests is 0.25. the weight W is 12N and the system is at equilibrium. find the friction force exerted on block A. (b)find the maximum weight W for which the system will remain...

**us history**

Since the Constitution has been ratified, how many states have been admitted to the union?

**physics**

An elevator and its load have a combined mass of 1700 kg. Find the tension in the supporting cable when the elevator, originally moving downward at 13 m/s, is brought to rest with constant acceleration in a distance of 43 m.

**physics**

i have plugged in all the numbers and got .51 what do i do at this point???

**physics**

A block is hung by a string from the inside roof of a van. When the van goes straight ahead at a speed of 26 m/s, the block hangs vertically down. But when the van maintains this same speed around an unbanked curve (radius = 135 m), the block swings toward the outside of the c...

**PHYSICS**

thanks for the detailed explanation

**chemistry**

HBr is a molecular substance that is a strong acid in water. Write an equation for its ionization in water. Use minimal integer numbers to balance the reaction. Include physical states in your answer, e.g., start with HBr(l).

**Chemistry**

0.01L KHP * 0.445M KHP = 0.00445 molKHP KHP and NaOH are in 1 to 1 ratio so, moles NaOH = 0.00445 so, 0.00445mol NaOH/ 0.01154L NaOH = 0.386M NaOH

**Physics**

Ok thanks.

**Physics**

A bicycle wheel that initially spins at 3 revolutions per second is braked uniformly to a stop in 1 second. A spot is painted at the outer edge of the wheel. How many revolutions does the spot go during the time it takes the wheel to stop? The answer I got was 0.5 but was inco...

**math**

What is the naming convention for a vector when two arrow point outward from a central point?

**PHYSICS**

F=Ma M =79kg a= 9.8ms^-2 (gravity) There is no other acceleration component since the aeroplane is at constant velocity so Force on pilot is... 79 x 9.8 = 774.2 N

**Algebra**

Sorry didn't see your second answer, great thanks a lot.

**Algebra**

I understand, your answer never mind. Thanks :)

**Algebra**

sorry don't understand

**Algebra**

100^0 one hundred to the zero power, would it be zero or one hundred?

**math**

32.5 - 45.8 please show steps!

**math**

x/7+5=10

**physics**

The left ventricle of the heart accelerates blood from rest to a velocity of +26 cm/s. (a) If the displacement of the blood during the acceleration is +1.9 cm, determine its acceleration (in cm/s2). (b) How much time does it take for the blood to reach its final velocity?

**physics**

The left ventricle of the heart accelerates blood from rest to a velocity of +23 cm/s. (a) If the displacement of the blood during the acceleration is +2.1 cm, determine its acceleration (in cm/s2). (b) How much time does blood take to reach its final velocity? in seconds

**physics**

A jetliner, traveling northward, is landing with a speed of 65 m/s. Once the jet touches down, it has 785 m of runway in which to reduce its speed to 5.0 m/s. Compute the average acceleration (magnitude and direction) of the plane during landing (take the positive direction to...

**algebra**

look at the algebraic equation that u posted previously. try to form an equation similar to that.

**algebra 1**

1. find a common multiple for the denominators of both fractions. 2. combine the fractions together. do not expand the numerator first. 3. cross multiply. 4. expand the terms 5. make x the subject. 6. solve.

**Physics - Circular motion**

A marble of mass m is placed on top of a bowling ball of radius r and allowed to roll from rest. derive the angle from centre of circle at which the marble loses contact with bowling ball. assume there is no friction between marble and bowling ball.

**3rd grade**

I am a number greater than 99 and less than 1,000. Two of my digits that aren't next to each other are the same. My tens digit could not be greater and it is 1 more than my hundreds digit. What number am I?

**conversion problems**

I don' know ask google

**Math**

What if the height of the water is only 15 cm, half the height of the hemisphere?

**Physics (Static Friction)**

divide by a 1000 your original answer is in N i believe also i would like to know how you solved this

**British Literature**

1. a 2. d 3. c 4. b 5. a 6. b 7. d 8. a 9. c i don't feel like doing any more. stop being so lazy

**MATHS**

to get the average do i add them all up and divide by the number of obsevations? say maths 646 divided by 14 = 46.1428 science 598 divided by 14 = 42.714 thanks

**MATHS**

oops sorry forgot the rest of the info: 14 students and their scores: MATHS 28 35 37 50 69 84 40 65 29 42 51 45 31 40 science 45 39 39 61 64 88 31 55 57 45 71 73 33 52 these are a random sample...... so if the kid gets 58 in maths how do you work out what his prdicted score wi...

**MATHS**

if a student scores 58 in a maths exam predict the score they would get in science??? Have no idea where to start on this answer other than having a good guess!! Can anyone help please??? Thanks Andrew

**Math**

What is 34920421-98349238

**Physics HELP**

C)

**FINANCE**

1 million bottles at $1 a bottle is $1 million minus 50 cents a bottle is $500,000 minus $200,000 fixed costs per year is $300,000 minus $150,000 in taxes is $150,000 left plus 10% per year from the bank is $165,000 times 5 years is $825,000 made. I would do it.

**math **

Factor the expression: x to the 2nd power+3x+2?

**chemistry**

124 atm

**Chem**

f the molecular mass for a chemical is 352.04 g/mol and the enthalpy of formation is -2137 kJ/mol, the heat change will be ______ kJ when 10.0 g of this chemical is formed.

**Chem**

f the molecular mass for a chemical is 352.04 g/mol and the enthalpy of formation is -2137 kJ/mol, the heat change will be kJ when 10.0 g of this chemical is formed.

**Math**

Square Root of 5 plus 2 Square root of 2 over 4 minus the square root of 5 simplify

**8th grade social studies**

which of the followin is a power of the president???

**algebra 2**

What is the Domain and Range of the Radical Parent function

**algebra 2**

What is the Domain and Range of the Radical Parent function

**Technology**

I'm writing an essay, and the first page is a cover page. Obviously, there shouldn't be a number there. How do I get rid of it so that there's still numbers on the other pages?

**Chemistry**

Is it possible to determine the Ka of a weak acid at points other than the halfway point of a titration? Explain.

**Chemistry**

Find the pH experimentaly .1 ml before and .1 ml after the equivalence point if the experimental equivalence point was found to be at 35 ml. In this titration, you are titrating 0.500 M NaOH with 0.250 M HCl.

**Chemistry**

How do you solve for the experimental pKa when doing a titration?

**Chemistry**

If you have 0.100 M Pyridine titrated with 0.100 M HCl, choose an appropriate indicator and explain?

**Algebra 2**

Find the solution of the exponential form in terms of logarithms 2^(2x+13) = 3^(x-45)

**Math**

find the solution of the expontetial equation 1+7^(5x)=19

**English**

We were eating apples, bananas, and watermelon on Tuesday.

**Geography**

I was wondering if a plane flew west and kept flying, would it be possible for it to never fly into night if it didn't stop?

**english**

how do sonnets compare with modern day music and songs? its for a presentation

**Biology**

aerobic respiration?

**Chemistry**

If there were two solutions- one with areagent(100% pure) mixed in water and the other solution containing the same reagent (99.9% pure) mixed in equal volume of water. How significant would the difference in concentration be between these two solutions?

**Physics**

Hey I'm lost on this physics problem can anyone tell me which equations i'm suppose to use in these questions a) A skier inhales a breath of air at Temp-air = 3.9 ¢XC and exhales it as Volume-air = 1.92 liters of air at Temp-body = 37 ¢XC and atmospheric pres...

**CHEMISTRY **

WHAT FACTORS ARE CONSIDERED TO BE STRESSES ON AN EQUILIBRIUM SYSTEM

**Physics**

1a. Two converging lenses, each of focal length 14.4 cm, are placed 60.6 cm apart, and an object is placed 26.9 cm in front of the first. Where is the final image relative to the second lens formed? b. What is the magnification of the system?

**Math**

What rate would it take to double an object valued currently at $100 in 6 years? I would like to know the answer and the equation/steps taken to solve the problem.

**Nutrition**

Why do sucrose-fed rats (high carb diet) consume less rat chow (protein, fat, fiber) than the control rats?

**Chemistry**

Determine the volume of a 0.550 M KMnO4 solution required to completely react with 2.55 g of Zn.

**7th grade**

37.5

**math**

What is the probability that exactly three children in a family of five children will be boys? Assume that P(boy)=P(girl)

**Volume of a rectangular prism**

Thanks. Therefore, the answer is 512. 2 x 16 x 2 = 64 4 x 32 x 4 = 512 Appreciate your help, Andrew

**Volume of a rectangular prism**

Hello, if the volume of a rectangular prism is LWH = 64 cubic inches, what are the dimensions of a rectangular prism with dimensions twice as long? Thank you!

**science**

Explain the similarities and differences of the multicellular stages of acellular and cellular slime molds.?

**MATH**

f(x)= 3x+9/(x^2-100) If this function has a horizontal asymptote, give its y-value Find the x-intercept(s). Find the y-intercept

**ENGLISH**

CAN SOMEONE HELP ME WITH WRITING AN EPIC POEM ABOUT A HERO? MY ASSIGNMENT IS DUE MAR. 1. IT HAS TO BE 4 PAGES LONG.

**Physics**

Suppose the coefficient of static friction between the road and the tires on a car is 0.60 and the car has no negative lift. What speed will put the car on the verge of sliding as it rounds a level curve of 29.3 m radius?

**Physics**

What is the smallest radius of an unbanked (flat) track around which a bicyclist can travel if her speed is 35 km/h and the μs between tires and track is 0.35?

**chemistry**

You are asked to prepare 150.0 mL of 3.15×10−2 M AgNO3. 2.) An aqueous solution is 6.40% methanol CH3OH by mass, with d = 0.988 g/mL} What is the molarity of CH3OHOH} in this solution?

**chemistry**

thank you

**chemistry**

1.)How many grams would you need of a sample known to be 99.81% AgN03 by mass? You are asked to prepare 150.0 mL of 3.15×10−2 M AgNO3. 2.) An aqueous solution is 6.40% methanol CH3OH by mass, with d = 0.988 g/mL} What is the molarity of CH3OHOH} in this solution?

**chemistry**

1.)How many grams would you need of a sample known to be 99.81% AgN03 by mass? You are asked to prepare 150.0 mL of 3.15×10−2 M AgNO3. 2.) An aqueous solution is 6.40% methanol CH3OH by mass, with d = 0.988 g/mL} What is the molarity of CH3OHOH} in this solution?

**chemistry**

2.) How much heat must be absorbed at 1357 K to melt a bar of copper (80 * 10 * 12 cm) assume d = 8.93 g/cm^3. The normal boiling point is 1357 K, and heat of fusion is 13.05 KJ/mol.

**chemistry**

How much heat, in kilojoules, is evolved when a 3.70 kg sample of molten Cu freezes? The normal boiling point is 1357 K, and heat of fusion is 13.05 KJ/mol. 2.) How much heat must be absorbed at 1357 K to melt a bar of copper (80 * 10 * 12 cm) assume d = 8.93 g/cm^3.

**chemistry**

How much heat, in kilojoules, is evolved when a 3.70 kg sample of molten Cu freezes? The normal boiling point is 1357 K, and heat of fusion is 13.05 KJ/mol. 2.) How much heat must be absorbed at 1357 K to melt a bar of copper (80 * 10 * 12 cm) assume d = 8.93 g/cm^3.

**AP Chemistry**

The combustion of 1.00 mol of sucrose,C12H22,O11, evolves 5650 kJ of heat. A bomb calorimeter has a calibrated heat capacity of 1.23 kj/degree Celsius. How many grams of sucrose should be burned to raise the temperature of the calorimeter and its contents from 23 degrees C to ...

**Philosophy**

What fallacies, if any, are present in the following passage? Can you please give reasons for your answer, that is, if you say that a fallacy has been committed, then show where the fallacy occurred, and explain why you think it is a fallacy? The following is the paragraph. Ba...

**Physics (2)**

Consider a charged ring of radius 43.4 cm and total charge 18 nC. We are interested in the electric field a perpendicular distance z away from the center of the ring. At what distance from the center of the ring does the electric field become maximum ..so E=kQ/(x^2)at a maximu...

**Physics**

Consider a charged ring of radius 43.4 cm and total charge 18 nC. We are interested in the electric field a perpendicular distance z away from the center of the ring. At what distance from the center of the ring does the electric field become maximum?

**Calculus**

how did you get the 8cm?

**Social Studies**

One of the biggest reasons for the increased European agricultural production in the medieval period was? A) the introduction of a heavier plow. B) the official support of the serfs by the popes. C) the introduction of new crops from the Byzantine world. D) the money invested ...

**Social Studies**

One of the biggest reasons for the increased European agricultural production in the medieval period was? A) the introduction of a heavier plow. B) the official support of the serfs by the popes. C) the introduction of new crops from the Byzantine world. D) the money invested ...

**algebra**

janice noticed that the number of problems she did for homework (x) formed a linear relationship with her quiz score (y). When she did 3 problems she earned a 25% and when she did 8 problems she earned a 60%. Write an equation to represent this situation.

**physics**

A ball is thrown up with a speed of 30m/s, what is the maximum height reached?

**4th grade math**

how do you find 3 equivalent fractions for 4/9??

**ENGLISH-POETRY**

NEED HELP WITH WRITING A 10 LINE IAMBIC POEM ABOUT WEATHER AND A 10 LINE TROCHIAC POEM ABOUT A PET

**Physics**

A 2 kg mass on a horizontal friction-free air track is accelerated by a string attached to a 100 kg mass hanging vertically from a pulley as shown. Compare the accelerations when the masses are interchanged, that is, for the case where the 100 kg mass dangles over the pulley, ...

**Biology**

Where do tertiary base pair interactions largely map onto the three-dimensional structure of tRNA? What is their purpose?

**Biology**

Devise an experiment, based on sucrose gradient sedimentation, that would demonstrate that proteins are synthesized on polyribosomes.

**Biology**

What is the difference between enterocolitis and gastroenteritis?

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