Thursday

July 24, 2014

July 24, 2014

Total # Posts: 675

**Physics **

A person of mass 50.0 kg is at the bottom of a cave. The cave has a depth of 32.5 meters and the person is to be pulled out of the cave vertically by a rope, starting from rest. What is the shortest amount of time that this could take if the rope can withstand a maximum tensio...

**Chemistry**

Im still confused.. is n 2? and if so would it look like this for A dHorxn=(2*2.84)-(2*-.227)??

**Math**

Solve (z +2)^ 4/3 = 4 where z is a real number please helpp

**Math **

Solve (z +2)^ 4/3 = 4 where z is a real number

**Chemistry ASAP**

Using a table of standard electrode potentials (such as the one in your textbook), calculate the standard cell potential for a cell made by placing a zinc electrode in a Zn2+(aq) solution which is connected by an electrolyte to a Ag+ (aq) solution containing a silver electrode...

**Science**

number 3 is correct.

**Physics **

A box of mass 1.50 kg is given an initial velocity of 12.5 m/s up an inclined ramp that makes an angle of 25.0o with the ground, which is horizontal. The coefficient of kinetic friction between the box and the ramp is 0.240. How long does the box slide up the ramp before it s...

**accounting**

In recent years, there has been a lot of media coverage about the funding status of pension plans for state employees. In many states, the amount of money invested in employee pension plans is far less than the amount estimated to be needed to pay them the retirement benefits ...

**Chemistry**

there is a graph yes, but it's confusing

**Chemistry**

A saturated solution of magnesium iodate has a temperature of 50°C. it contains 175g of dissolved solute. What is the volume of the solution?

**Chemistry**

At what temperature (∘C) will xenon atoms have the same average speed that Cl2 molecules have at 35∘C?

**Chemistry**

Methane gas, CH4, is sold in a 43.0L cylinder containing 5.91kg .What is the pressure inside the cylinder (in kilopascals) at 21∘C?

**Chemistry**

Traffic on the German autobahns reaches speeds of up to 230 km/h.At what temperature (∘C) do oxygen molecules have this same average speed?

**Chemistry**

What is the molecular mass of a gas that diffuses through a porous membrane 1.86 times faster than Xe?

**Chemistry**

An unknown gas is placed in a 1.500 L bulb at a pressure of 356 mm Hg and a temperature of 22.5 ∘C, and is found to weigh 0.8108g .What is the molecular mass of the gas?

**Chemistry**

A small cylinder of helium gas used for filling balloons has a volume of 2.85L and a pressure of 13300kPa at 25 ∘C.How many balloons can you fill if each one has a volume of 1.50L and a pressure of 1.26atm at 25 ∘C?

**Chemistry**

Oxygen gas is commonly sold in 48.0L steel containers at a pressure of 130atm .What volume (in liters) would the gas occupy if its temperature was raised from 20.5∘C to 40.0∘C at constant 130atm ?

**Physics **

An airplane needs to fly due south. The plane can fly at a speed of 720.0 km/hr in still air. If there is a wind blowing to the northeast at 70.0 km/hr, in what direction should the plane fly to maintain its heading of due south? How long will it take to fly a 1500.0 km distance?

**chemistry urgent**

NH4NO3(s)+H2O(l)→NH4NO3(aq) ΔH = +25.7 kJ. What is the final temperature in a squeezed cold pack that contains 45.5g of NH4NO3 dissolved in 125 mL of water? Assume a specific heat of 4.18J/(g⋅∘C) for the solution, an initial temperature of 29.0∘C, ...

**Chemistry**

Calculate ΔH∘f (in kilojoules per mole) for benzene, C6H6, from the following data: 2C6H6(l)+15O2(g)→12CO2(g)+6H2O(l) ΔH∘ = -6534kJ ΔH∘f (CO2) = -393.5kJ/mol ΔH∘f (H2O) = - 285.8kJ/mol

**Chemistry**

Assuming that the specific heat of the solution is 4.18 J/(g⋅∘C) and that the calorimeter itself absorbs a negligible amount of heat, calculate ΔH in kilojoules for the reaction CaO(s)+H2O(l)→Ca(OH)2(aq) When 1.045 g of CaO is added to 50.0 mL of water a...

**Math**

Can someone please work out the steps in solving this elimination problem. Thank you. The problem is x + 2y = -7 x - 5y = 7

**social studies**

What were the results of the Korean War? What impact did it have on American society?

**Math**

Solve by elimination x + 2y = -7 x - 5y = 7

**Math/Physics **

John is driving at a constant speed of 20.0 m/s when he passes Jane, who is traveling in the same direction at 15.0 m/s at the moment that John passes her. If Jane is accelerating at 2.0 m/s2, how far will Jane drive before she catches up to John? How much time passes from whe...

**Physics **

A crate begins sliding down a frictionless incline of 25.0o. If the objects begins sliding from rest and takes 1.50 sec to slide down the incline, what is the speed of the crate as it leaves the incline? How long is the incline?

**Physics**

John is driving at a constant speed of 20.0 m/s when he passes Jane, who is traveling in the same direction at 15.0 m/s at the moment that John passes her. If Jane is accelerating at 2.0 m/s2, how far will Jane drive before she catches up to John? How much time passes from wh...

**Physics **

Draw each of the following vectors on graph paper, then find the x- and y- components. Make sure to include units in your answers for the components. a) ⃑r = (65 m, 30degrees above the positive x-axis) b) ⃑v = (125 m/s, 40degrees below the negative x-axis) c) ͈...

**Calculus**

negative one third t minus 1

**Calculus**

Two full 48-gallon tanks begin draining at t = 0. Tank Alpha's volume is changing at a constant rate of -16/5 gal/min. The rate at which Tank Bravo's volume is changing is given by r(t)=-1/3t-1 gal/min. a) How much water is in each tank after 5 minutes? b) Which tub dr...

**Physics**

A cubic meter of some material has a mass of 6400 kg. The block of material is lowered into a lake by a strong cable until the block is completely submerged. Draw a free-body diagram for the block. (Do this on paper. Your instructor may ask you to turn in your work.) Find the ...

**science**

30 cubic meters of argon gas are kept under constant pressure. The gas is heated from 10.0 degrees Celsius to 293 degrees Celsius. What is the new volume of the gas?

**physics**

A DC circuit has a single battery of voltage V = 10.0 V attached to a resistor R = 100 Ohms. If the voltage is increased to 20.0 V, then by what factor does the power emitted by the resistor increase?

**Physics**

A 2 kg ball is rolled down a hill 25 m tall. When it reaches the bottom of the hill it is traveling at 15.1 m/s. How much energy was dissipated due to friction?

**physics**

an unpolarised light is incident on the boundary between two transparent media. State the contition when the reflected wave is totally plane polarised.

**Physics**

It takes 56 J to push a block 4 m. If the force is in the same direction as the displacement, what is the force on the block?

**English**

Presents I think

**Please Help with 2 Physics Problems???**

1) In a two-dimensional tug-of-war, Alex, Betty, and Charles pull horizontally on an automobile tire at the angles shown in the picture. The tire remains stationary in spite of the three pulls. Alex pulls with force FA of magnitude 207 N, and Charles pulls with force FC of mag...

**Math**

Thank you Reiny

**Math**

Can someone help me to solve this scientific notation equation. (5.7 x 10^3)^-^4

**Physics**

A car accelerates from 12m/s to 25m/s in 6.0s. What is its uniform acceleration? How far did it travel in this time?

**Physics**

A plane flies 407 km east from city A to city B in 44.0 min and then 871 km south from city B to city C in 1.90 h. For the total trip, what are the (a) magnitude (in km) and (b) direction of the plane's displacement, the (c) magnitude (in km/h) and (d) direction of its ave...

**Statistics**

Determine if the following are probability distributions (if no, state why). a. X 3 6 9 12 15 P(X) 4/9 2/9 1/9 1/9 1/9

**algebraic expressions**

write a situation that can be represented by the algebraic expression 3.25d

**Statistics**

What does the empirical rule say about the proportion of players who are between 62.7 inches and 75.3 inches? c.

**Pre-Algebra**

The treasurer of the student body at a college reported that the receipts from a recent contact totaled $916; Furthermore, he announced that 560 people had attended the concert. Students were charged $1.25 each for admission to the concert, and adults were charged $2.25 each. ...

**Science**

which of the following do rain forests and taiga have an common? A. similar average annual rainfalls. B. similar average annual temperature C. heavily populated with trees. D. tend to occur in similar latitudes

**Math**

Yes

**Math**

Snooki has a total of 25 quarters and pennies in her pocket. She has $2.32 altogether. How many quarters and pennies were sold?

**World History ;-;**

Which of the following was a result of the development of Christianity in the Byzantine empire?

**Stats**

Suppose the following data are selected randomly from a population of normally distributed values. 42 51 43 48 41 57 54 39 45 48 45 39 46 Construct a 95% confidence interval to estimate the population mean. Round the intermediate values to 2 decimal places. Round your answers ...

**Chemistry**

1) A dog has the same mass for 3 years. State whether this represents an equilibrium or steady state situations, and give your reasons. I'm not sure if I got this question right... I think this is a steady state because the dog is opened to the environment where oxygen is ...

**Chemistry**

For the reaction Zn(OH)2(s)+4CN-(aq)->Zn(CN)4 2-(aq)+2OH-(aq) find [CN-] when 8.5 g of Zn(OH)2 are dissolved in 1.00 L of solution.

**physics**

a .150kg object tied to a string is whirled in a horizontal circle ata constant angular speed of 3.50 revolutions per second. the tension is the string is 75newtons. what is the length of the string?

**Can someone check these answer for me?**

1. B 2.B 3.D 4.D 5.A

**Can someone check these answer for me?**

is someone on

**science help plzzz**

PLEASE HELP

**science help plzzz**

1. A 2.D 3.B 4.C 5.B

**Chemistry**

8======D

**Physics**

A "swing" ride at a carnival consists of chairs that are swung in a circle by 19.8 m cables attached to a vertical rotating pole, as the drawing shows. Suppose the total mass of a chair and its occupant is 144 kg. (a) Determine the tension in the cable attached to th...

**Physics**

At an amusement park there is a ride in which cylindrically shaped chambers spin around a central axis. People sit in seats facing the axis, their backs against the outer wall. At one instant the outer wall moves at a speed of 3.44 m/s, and an 64.3-kg person feels a 277-N forc...

**Physics**

A centrifuge is a device in which a small container of material is rotated at a high speed on a circular path. Such a device is used in medical laboratories, for instance, to cause the more dense red blood cells to settle through the less dense blood serum and collect at the b...

**chemistry**

Calculate the number of hydrogen molecules formed when 5.6 mL of ammonia at STP is decomposed by the following reaction: ___NH3 „³ ___ N2 + ___ H2

**chemistry**

Calculate the volume of oxygen at STP required to burn 3.7 kg C3H6O2 producing CO2 & H2O:

**SAT prep math **

Maria has two piggy banks. In one piggy bank she saves dimes and in the other she saves nickels. At the end of each month she saves 40 nickels and 30 dimes

**Physical Science**

a student is given a 10 gram sample of gold that has a density of 19.32g/cm3. The student is then given a 5 gram sample of an unknown substance and told the density of the unknown substance is 19.32g/cm3. What is the unknown substance

**chemistry**

determine the mass of CO2 produced when 51.2 g of CaO is reacted with 50.0 g of C according to the unbalanced equation CaO + C --------CaC2 =CO2

**chemistry**

in the reaction of magnesium metal with hydrochloric acid to produce magnesium chloride and hydrogen gas. If 4.59 mol of magnesium and 4.59 mol of hydrochloric acid are reacted, how many moles of magnesium chloride are produced ?

**Please Help with calculus**

How to evaluate x=0 and dx=-.03? I got(1/9)e^(x/9)dx as dy of e^(x/9)and I don't know how I should plug them in.

**Calculus**

Let y=e^(x/9). a) Find the differential dy. dy = b) Evaluate dy if x=0 and dx=−0.03. dy =

**Calculus**

Find the linear approximation L(x) of ln(x) at the point a = 12.

**Calculus**

Find the equation of the tangent line to the curve (piriform) y^2=x^3(4−x) at the point (2,16−−ã). a. Find dy/dx at x=2. dy/dx= b. Write the equation of the tangent line to the curve.

**Calculus**

Find the linear approximation L(x) of ln(x)at the point a = 12.

**Calculus**

The radius of a circular disk is given as 51 cm with a maximum error of 0.04 cm. Use differentials to estimate the maximum error and percent error in the calculated area of the disk.

**english **

please answer the last question

**english**

give two examples in the giant's house for character, theme, plot, style, point of view

**chemistry**

How much carbon dioxide gas is there in a 34.3 L container at 34.0◦C and 5.49 atm? answer in grams

**Calculus**

Evaluate the following limit, if it exists: lim h-->0 ((sqrt9+h)-3/(h)

**Calc**

Oscar Corporation is planning to construct an elliptical gate at its headquarters. The width of the ellipse will be 5 feet across and its maximum height along the center will be 3 feet. The company wants to place two bright spots at the foci of the ellipse. How far from the ce...

**math**

kate cut a pizza into fourths. karl cut a pizza of the same size into sixth. After they each ate some pizza, they had the same fraction of pizzas left. What fraction of each pizza was left?

**pre calc**

Find all solutions of the equation tan^5 x - 9tan x =0. The answer is Ak\pi where k is any integer, the constant A= ??.

**math**

Find all solutions of the equation 3sin^2 x -7sin x +2 = 0 in the interval [0,2\pi). The answer is x_1= ? and x_2= ? with x_1<x_2.

**since and cosine please help me!**

that is not right according the program

**since and cosine please help me!**

Simplify and write the trigonometric expression in terms of sine and cosine: ((2+tan^2 x)(sec^2 x))-1 = (f(x))^2 f(x)= ???

**sine and cosine**

Simplify and write the trigonometric expression in terms of sine and cosine: sin x + (cot x)(cos x) = (1/f(x)) f(x)= ?

**cosine and sine HELP!**

Simplify and write the trigonometric expression in terms of sine and cosine: ((2+tan^2 x)(sec^2 x))-1 = (f(x))^2 f(x)= ???

**math**

Simplify and write the trigonometric expression in terms of sine and cosine: sin x + (cot x)(cos x) = (1/f(x)) f(x)= ?

**chemistry**

Thimerosal is an organic compound (gram molecular mass = 404.8 g/mol) used to inhibit bacterial growth. A .100%solution of thimerosal is sometimes used as an antiseptic. Assume that this solution has a density of 1.00 g/mL. A. how many grams of thimerosal are found in .500 g o...

**math**

Simplify and write the trigonometric expression in terms of sine and cosine: sin x +(cot x)(cos x) = 1/f(x) f(x)= ?

**math**

If tan^2(t) - sin^2(t) = sin^a(t)\cos^b(t), then the positive power a = the positive power b =

**math**

2a2+5a-25=0

**phisics**

If You do 100 j of work to elevate a bucket of water,what is its gravitational potential energy relative to its starting position?

**angles**

A survey team is trying to estimate the height of a mountain above a level plain. From one point on the plain, they observe that the angle of elevation to the top of the mountain is 25 degrees. From a point 1225 feet closer to the mountain along the plain, they find that the a...

**trig **

The radian measure of an angle of 182 degrees is ?

**math**

The radian measure of an angle of 182 degrees is

**Pre calulus only 15 min left HELP!**

((ln(x))^1/2)/(ln(x^1/2))=6 solve for x

**Physics**

500 calories of heat is added to 2.0 g of water at 80 degrees Celsius. How much steam is produced?

**math**

write the metric unit of length that is reasonable. a door is about 1 blank wide

**Math**

The sum of twice a number and another number is 24. The difference of twice the first number and the other number is 12. Which system would model this situation, and what is the solution?

**math**

what is answer of 7 cubed

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