Friday

January 20, 2017
Total # Posts: 1,376

**Physics**

A car driving along a highway at a speed of 23 m/s strays onto the shoulder. Evenly spaced parallel grooves called “rumble strips” are carved into the pavement of the shoulder. Rolling over the rumble strips causes the car's wheels to oscillate up and down at a ...

*November 21, 2011*

**Chemistry**

a real gas would behave most like an ideal gas under conditions of

*November 18, 2011*

**pre algebra**

my numerator is a prime number My denominator is divisible by 2 i am equivalent to 1/5

*November 16, 2011*

**Chemistry**

What is the trend in atomic size in the series of Group IIA elements Be through Ra?

*November 14, 2011*

**Physics**

A record has an angular speed of 47 rev/min. Through what angle does it rotate in 1.07 s? Answer in units of ra

*November 11, 2011*

**Excel-Exponential Fits**

Hey Im trying to plot this set of data: 0 0 10 0.6 20 1.01 30 1.428 40 2 50 2.3 60 2.57 70 2.8 80 3.05 90 3.35 100 3.54 110 3.73 120 3.9 130 4.08 140 4.25 150 4.39 160 4.53 170 4.65 180 4.754 190 4.846 200 4.943 210 5.011 220 5.111 230 5.175 240 5.23 250 5.295 260 5.356 270 5....

*November 11, 2011*

**Calculus (2)**

oh I get it now, tnx!

*November 11, 2011*

**Calculus (2)**

and how do you get (x+1)?

*November 11, 2011*

**Calculus (2)**

Tnx for the quick answer, but I still have a question: why is it - in y' = e^-x (-) (x+2)e^-x instead of a + ?

*November 11, 2011*

**Calculus (2)**

find the first and second derivative of: f(x) = (x+2)/e^x I get to: f'(x) = e^x - (x+2)(e^x) / (e^x)^2 I'm stuck at that

*November 11, 2011*

**calculus**

last one is supposed to be dy/dx = 1 / ((e^y^2 * 3y^2) - (9^xsin(3y)ln3) - (1+3y))

*November 11, 2011*

**calculus**

considering that x is the independent variable in this equation: y + y^3 + 3 = e^y^2 + 3^x * cos(3y) - x Evaluate dy/dx I get to: dy/dx (1+3y) = e^y^2 * 3y^2 * dy/dx + 3^x * ln3 * (-sin(3y)) * 3 *dy/dx -1 Will it give me? dy/dx(1+3y) = dy/dx((e^y^2 * 3y^2) + (3^x * ln3 * (-sin...

*November 11, 2011*

**Organic Chemistry**

What is the mechanism for the removal of bromine from dibromocholesterol using Zinc and acetic acid?

*November 9, 2011*

**Math**

In Mrs Halls class of 30 students, 17 have computers at home and 20 have cassettes. If 4 students in the class have neither a computer or a cassette, how many of the 30 students have both?

*November 7, 2011*

**Maths**

Calculate speed give your answers in km/p hour Distance = 18 KM Time = 12 minutes S - T

*November 6, 2011*

**Physics**

In Fig. 6-34, blocks A and B have weights of 46 N and 23 N, respectively. (a) Determine the minimum weight of block C to keep A from sliding if μs between A and the table is 0.21. (b) Block C suddenly is lifted off A. What is the acceleration of block A if μk between...

*October 23, 2011*

**Physics**

A student, crazed by final exams, uses a force of magnitude 86 N and angle θ = 61° to push a 5.2 kg block across the ceiling of his room, as in Figure 6-52. If the coefficient of kinetic friction between the block and the ceiling is 0.34, what is the magnitude of the ...

*October 23, 2011*

**Physics**

A warehouse worker exerts a constant horizontal force of magnitude 89.0 N on a 43.0 kg box that is initially at rest on the horizontal floor of the warehouse. When the box has moved a distance of 1.60 m, its speed is 1.10 m/s. What is the coefficient of kinetic friction ...

*October 23, 2011*

**Physics**

A warehouse worker exerts a constant horizontal force of magnitude 89.0 N on a 43.0 kg box that is initially at rest on the horizontal floor of the warehouse. When the box has moved a distance of 1.60 m, its speed is 1.10 m/s. What is the coefficient of kinetic friction ...

*October 23, 2011*

**Physics**

A 3.4 kg block is pushed along a horizontal floor by a force of magnitude 21 N at a downward angle θ = 40°. The coefficient of kinetic friction between the block and the floor is 0.26. What the magnitude of the block's acceleration?

*October 23, 2011*

**college physics**

A 0.384 kg puck, initially at rest on a horizon- tal, frictionless surface, is struck by a 0.189 kg puck moving initially along the x axis with a speed of 2.7 m/s. After the collision, the 0.189 kg puck has a speed of 1.7 m/s at an angle of 28 to the positive x axis. ...

*October 22, 2011*

**physics**

A 2200 kg car is travelling at 45 km per hour when its brakes are applied and it skids to a stop. If the coefficient of friction between the road and the tires is 0.70 how far does the car go before stopping?

*October 18, 2011*

**algebra world problems**

1+1

*October 17, 2011*

**PHYSICS HELP PLEASE!**

Here is how it is phased in the question: (2) The orbiting space shuttle moves around the Earth well above 99% of the atmosphere, yet it still accumulates an electric charge on its skin due (in part) to the loss of electrons caused by the photoelectric effect from sunlight. ...

*October 13, 2011*

**PHYSICS HELP PLEASE!**

The maximum wavelength of light emitted from a blackbody that will emit electrons from a given piece of metal is 255nm. What is the fraction of total energy emitted from the black body that emits electrons? I set up the integral: Int(8πhcλ^-5)/(e^(hc/λkT)-1)) ...

*October 13, 2011*

**physics**

A piece of copper is made into a rod with a square cross-section. The side of the square is 2.00 centimeters. The resistivity of copper is 1.7 \cdot 10^{-8} \Omega\cdot {\rm m}. An unknown electric field E, directed along the rod, creates a current of 12.0 amperes through the ...

*October 10, 2011*

**PHYSICS**

In a particular region of Earth's atmosphere, the electric field above Earth's surface has been measured to be 151 N/C downward at an altitude of 280 m and 167 N/C downward at an altitude of 430 m. Calculate the volume charge density of the atmosphere, assuming it to ...

*October 10, 2011*

**Physics**

An infinitely long line charge of uniform linear charge density λ = -3.00 µC/m lies parallel to the y axis at x = -2.00 m. A point charge of 4.70 µC is located at x = 1.50 m, y = 2.50 m. Find the electric field at x = 2.50 m, y = 2.00 m. I added the vectors, ...

*October 10, 2011*

**Physics**

In a particular region of Earth's atmosphere, the electric field above Earth's surface has been measured to be 151 N/C downward at an altitude of 280 m and 167 N/C downward at an altitude of 430 m. Calculate the volume charge density of the atmosphere, assuming it to ...

*October 9, 2011*

**algebra**

9/10Y = 36 What is Y

*October 6, 2011*

**s.s**

how does gps works

*October 5, 2011*

**math**

This is a quadratic equation where perimeter is only 3 sides so p=l x 2w and if width is x then side is 2000-2x then area = x(2000-2x) = 2000x-2x^2 the vertex of this parabola will be x=500 and length is 1000 for area=500000 calculus derivative =2000-4x=0 for max-min point and...

*October 3, 2011*

**Chemistry**

The solubility of a certain compound in ice-cold water is 0.22g in 100mL. Its solubility in hot water is 4.35g in 100mL What is the best possible percent recovery we can expect for the re-crystallization of this compound in water?

*September 29, 2011*

**chem**

why are electron groups that repel each other higher in energy?

*September 25, 2011*

**physics**

yes

*September 21, 2011*

**Statistics**

Find the numerical value of k: -2.35=[(k-100)/15]

*September 21, 2011*

**statistics**

Based on data collected by the National Center for Health Statistics and made available to the public in the Sample Adult database, an estimate of the percentage of adults who have at some point in their life been told they have hypertension is 23.53 percent. If we select a ...

*September 13, 2011*

**math**

decimal value for 1/11

*September 12, 2011*

**Math**

angel m1 =125 dagrees angek m2= ?

*September 7, 2011*

**chemistry**

If the density of a certain alcohol is 0.785 g/mL, what volume of the alcohol would have a mass of 75.0g?

*September 2, 2011*

**spelling**

how do you make a spelling triangle

*August 31, 2011*

**finance**

$63,584.00is the correct answer. $80 x 5.68 = 454.40 454.40 x 360 = 163,584.00 163,584.00 - 100,000 = $63,584.00 D.) $63,584.00

*August 31, 2011*

**physics**

A car travels along a straight stretch of road. It proceeds for 15 mi at 55 mi/h, then 29 mi at 43 mi/h, and ﬁnally 37.9 mi at 33.7 mi/h. What is the car’s average velocity during the entire trip? Answer in units of mi/h

*August 23, 2011*

**chemistry**

Calculate the percent yield if 104 g of CH3CO2CH2CH3 is produced by the reaction of 111 g of CH3CO2H according to the following equation: CH3CO2H(l) + CH3CH2OH(l) ¨ CH3CO2CH2CH3(l) + H2O(l)

*August 14, 2011*

**Statistics**

I have recently administered an employee survey at a call center. I found a Pearson r of -.66 between the employees' ages and their scores on an employee engagement scale. What does this finding represent/mean? Also, there is a relationship between gender and employee ...

*August 5, 2011*

**chemistry**

Given that ΔHof of copper (II) chloride, CuCl2(s), is –220.1/kJ and ΔHof of copper (I) chloride, CuCl(s), is –137.2 kJ, calculate ΔHo for the reaction when 14.0 g of copper is used: CuCl2(s) + Cu(s) → 2 CuCl(s)

*August 3, 2011*

**statistics**

Consider the average available for all hotel rooms from the previous assignment. Identify the point estimate of the average number of available hotel rooms in this lesson from each sample. Construct and Interpret a 95% confidence level for the true mean number of available ...

*August 2, 2011*

**Chemistry**

I don't agree this answer. number %khp so high

*July 31, 2011*

**physics**

a student tries to open a door at a distance of 1 cm from the hinge at a distance of 10 cm from the hinge and at a distance of 50 cm from the hinge why is a larger force required at 1 cm than at 50 cm?

*July 23, 2011*

**telemarketing**

A telemarketer with B2B Communications has a 20 percent historical probability of making a sale during a shift where 100 calls were made. Assign a random variable x, where the value of x is equal to the number of sales made during the shift. Describe the probability ...

*July 23, 2011*

**statistic**

The average score on a standardized test is 750 points with a standard deviation of 50 points. If 2,000 students take the test at a local school, how many students do you expect to score between 700 and 800 points?

*July 21, 2011*

**statistics**

The average score on a standardized test is 500 points with a standard deviation of 50 points. What is the probability that a student scores between 450 and 600 on the standardized test?

*July 21, 2011*

**accounting**

A company has an overhead application rate of 125% of direct labor costs. How much overhead would be allocated to a job if it required total direct labor cost of $20,000? $5,000. $16,000. $25,000. $125,000. $250,000. The R&R Company's production costs for August are: ...

*July 16, 2011*

**geometry**

The diagonals of rhombus FGHJ intersect at point K. If side GH is equal to 3x - 10 and side JH is equal to 6x - 19, find x.

*July 14, 2011*

**English**

Does anyone know what this verse means: "shall summon to unwelcome bed"? Here is the full stanza of the poem. It is from through the looking glass? Come, hearken then, ere voice of dread, With bitter tidings laden, Shall summon to unwelcome bed A melancholy maiden! ...

*July 11, 2011*

**Algebra**

It is possible for a quadratic equation to have no real-number solutions:Solve : x2 + 5x + 3 = 0

*July 10, 2011*

**chem**

it dissolves

*July 9, 2011*

**algebra 2**

If Q varies inversely as the square root of R and Q=2 when R=4, what is Q when R is 25? does Q=625 im not sure can someone double check it for me.

*July 8, 2011*

**algrebra 2**

can someone please help me im stumped on these two. use analytical methods to solve the equation. 1+(1/x)=(42/x²) (7/x-4)=1+(9/x+4)

*July 8, 2011*

**algebra**

Solve using the substitution method. Show your work. If the system has no solution or an infinite number of solutions, state this. 4x + 4y = -36 4x + 4y = 12

*July 6, 2011*

**Chemistry**

For the reaction HNO3+HCl=NO2Cl+H20 What is the equilibrium constant at 25 C and 75 C

*July 1, 2011*

**statistics**

.099

*June 25, 2011*

**trig**

sinx+sinxcot^2x=cscx prove each identity

*June 24, 2011*

**trig**

tan(theta)-1= sin^2(theta)-cos^2(theta)/ sin(theta)cos(theta)+cos^2(theta) prove each identity

*June 24, 2011*

**Chemistry**

sulfur

*June 17, 2011*

**chemistry**

what is the volume of 4.4 moles of Cl2 at 285 kelvin and 0.87 atm. (R=0.0821 k*atm/mol*k)

*June 15, 2011*

**Math**

3(x-2)+4(2x-6)=6(x-4)+8(2x+1)x=

*June 11, 2011*

**Math**

What is the square root of 6 times the square root of 9 if there is no perfect square of 6

*May 23, 2011*

**english**

1890-1950 American MLA Format

*May 15, 2011*

**english**

I need to write a mini research paper on a modernist poet of my choice... I'm having trouble deciding on what poet to use and how i can develop a strong thesis.. any help would be much appreciated.

*May 15, 2011*

**american government**

The factor that normally has the most impact on the president's level of popular support is a. world conditions. b. the condition of the nation's economy. c. the national crime rate.d. the president's skill in the use of television. e. the condition of nation's...

*May 13, 2011*

**Statistics**

Suppose that the average grade for all people who take this course in statistics is 83 with a standard deviation of 3.5. If your particular class has an average of 89, can you conclude that your class is better than average at the 90 percent confidence level? Label and ...

*May 13, 2011*

**physics**

The function y(x, t) = (25.0 cm) cos(ðx - 15ðt), with x in meters and t in seconds, describes a wave on a taut string. What is the transverse speed for a point on the string at an instant when that point has the displacement y = +22.0 cm?

*May 13, 2011*

**Chemistry**

so if the pka is 4.5 the range will be from 3.5 to 5.5?

*May 12, 2011*

**Chemistry**

what is the pH range of the buffering region? is that when ph=pKa?

*May 12, 2011*

**government**

the federalist papers were written to what? win support for the constitution in new york expose the lack of civil liberties protected in the constitution urge ratification of the constitution in virginia condemn the constitution for the absence of any metioned god

*May 11, 2011*

**UCI Chemistry Webworks**

For the following balanced equation: 2 Ag+ (aq) + Cu(s) <<->> Cu2+ (aq) + 2 Ag(s) Which letter corresponds to the correct cell notation at standard state conditions? A. 2Ag+(aq) | Cu2+(aq) || 2Ag(s) | Cu(s) B. Cu(s)| Cu2+(aq) || Ag+(aq) | Ag(s) C. Ag+(aq) | Cu2+(aq...

*May 7, 2011*

**account/check please**

answer is A

*May 4, 2011*

**math**

do you know how to solve it

*May 4, 2011*

**math**

Male: 60,63,65,70,66,80,85,73,79,80,83,85,81,76, 77,90,91,88,78,92 Females: 62,69,70,72,78,77,79,83,80,88,90,90,98,100, 66,67,65,63,69, 83 Can you hellp me I need to find: A) P value and the Z value of this data with a Alpha Value of 0.05.

*May 4, 2011*

**MATH Please help me**

Male: 60,63,65,70,66,80,85,73,79,80,83,85,81,76, 77,90,91,88,78,92 Females: 62,69,70,72,78,77,79,83,80,88,90,90,98,100, 66,67,65,63,69, 83 Can you hellp me I need to find: A) P value and the Z value of this data with a Alpha Value of 0.05.

*May 4, 2011*

**Math (stastiscs)**

Male: 60,63,65,70,66,80,85,73,79,80,83,85,81,76, 77,90,91,88,78,92 Females: 62,69,70,72,78,77,79,83,80,88,90,90,98,100, 66,67,65,63,69, 83 Can you hellp me I need to find: A) P value and the Z value of this data with a Alpha Value of 0.05.

*May 4, 2011*

**Math**

A lawn service will fertilize a lawn at at a rate of 59cents per 100 square feet. What is the price they will charge to fertilize a 125foot x 140foot rectangular lawn? Express answer to the nearest cent.

*May 1, 2011*

**math**

1/9

*April 29, 2011*

**physics**

Stan raises a 1110 N piano a distance of 5.00 m using a set of pulleys. Stan pulls in 20.0 m of rope.

*April 27, 2011*

**statistics**

If you have a population mean of 50 and a population standard deviation of 5 and you select a sample size of 100, what is the probability that the sample mean is between 47 and 49.5?

*April 27, 2011*

**math**

how do I determine the compounding rate required to turn $350 into $14,000 over 30 years? Thank you

*April 26, 2011*

**physics**

DONT KNOW CAUSE THERE IS NO FORMULA FOR IT

*April 24, 2011*

**Chemistry**

Magnesium is found in the ore,magnesite, MgCO3. The ore decomposes when heated to form magnesium oxide and carbon dioxide. Write the balanced equation for this reaction.

*April 24, 2011*

**chemistry**

What is the pH of a solution made by adding grams of NH4Cl, to 550 mL of 0.205 M NaOH?

*April 20, 2011*

**math**

can some one help 3>4+5+

*April 19, 2011*

**substition algebra**

solve x & y: 3X-6Y(-6X+34)=30

*April 19, 2011*

**Math**

Sean's mom was 27 years old when he was born. When Sean is 14 years old his mother's age will contain the same two digits as Sean's age. The next time that Sean's age and his mother's age contain the same 2 digits ____ years later.

*April 19, 2011*

**Math**

Today Justin reached 1/11 the age of his mother was when he was bron. Today, Justin's mother is _____ times as old as Justin.

*April 19, 2011*

**Math**

find the derivative f(x)= 4xe^x f(x) = ln (2z-11)^7 f(x) = ln (x-1/3x+1)

*April 17, 2011*

**chemistry**

. Given the following stocks 4M NaCl, 3M NaOH, 5M HCl (a) Prepare 200ml of a solution containing 0.5M NaCl and 0.1M (b) Prepare 300ml of a solution containing 0.5M NaCl (c) Prepare 200ml of a solution containing 0.5M NaCl and 0.1M HCl

*April 15, 2011*

**algebra**

Tad was delivering lunch to a local office building. His first delivery was to the middle floor of the building. He then took th elevator up 4 floors for the next delivery, down 6 floors for his third delivery, and up 7 floors for his final delivery. He was then on the top ...

*April 14, 2011*

**physics**

At the equator, the earth’s field is essentially horizontal; near the north pole, it is nearly vertical. In between, the angle varies. As you move farther north, the dip angle, the angle of the earth’s field below horizontal, steadily increases. Green turtles seem to...

*April 14, 2011*

**Fractions**

Add the following. 1/2+3/12+1/4; 3/12+1/2+1/4;5/6+1/3;1/4+3/8+1/4

*April 13, 2011*

**Fractions**

Crate has 24 pieces of fruit . 1/2 are oranges, 1/4 are mangos and 2/8 are pineapples. Howmany oranges are there, how many mnagos and how many pineapples? Al ate 1/8 of a sandwich,Bob ate 1/8, then Bill ate 1/4. How much did they eat all together? What fraction was left. 24 ...

*April 13, 2011*