Tuesday

April 28, 2015

April 28, 2015

Total # Posts: 1,157

**algebra**

Briana's second test score was 8 points higher than her first score. Her third score was 88. She had a B average (between 80 and 89 inclusive) for three tests. What can you conclude about her first test score?
*September 3, 2012*

**Chemistry**

How do I calculated the mass and moles of nitric acids when only given 2ml of concentrate nitric acid
*August 30, 2012*

**Math**

The half-life of radioactive strontium-90 is approximately 28 years. In 1962, radioactive strontium-90 was released into the atmosphere during testing of nuclear weapons, and was absorbed into people's bones. How many years does it take until only 6 percent of the original...
*August 28, 2012*

**physics**

A tourist being chased by an angry bear is running in a straight line toward his car at a speed of 3.7 m/s. The car is a distance d away. The bear is 27 m behind the tourist and running at 6.0 m/s. The tourist reaches the car safely. What is the maximum possible value for d?
*August 23, 2012*

**physics**

What is the magnitude of the average acceleration of a skier who, starting from rest, reaches a speed of 6.8 m/s when going down a slope for 2.5 s?
*August 23, 2012*

**Physics**

A block of mass m 1 sits at rest on a table over a hole in the table. From below the table, a bullet of mass m 2 is fired vertically upwards into the block. The bullet imbeds itself in the block. The block and bullet rise to a maximum height h. What is the bullet’s ...
*August 6, 2012*

**Differential Equations**

Solve the differential equation below with initial conditions. Compute the first 6 coefficient. Find the general pattern. (1-x)y"-y'+xy=0 y(0)=1, y'(0)=1
*July 9, 2012*

**Math**

Find the balance in the account. $2,500 principal earning 4%, compounded quarterly, after 4 years
*July 8, 2012*

**Chemistry**

You mix 19.5 gallons of a mixture containing 12 wt% NaCl (sol'n density = 1.0837 g/cm^3) with V2-gallon sol'n that is 20 wt% NaCl (sol'n density = 1.1453 g/cm^3). Needed mixture is 19 wt% NaCl Whats the V2 in gallons? (all solutions are in water so just dealing ...
*July 7, 2012*

**chemistry**

How many milliliters of 0.237 M HCl are needed to react with 52.2g of CaCO3? 2HCl(aq) + CaCO3(s) --> CaCl2(aq) + CO2(g) + H2O(l)
*July 6, 2012*

**math**

five rental cars require four new tires. the price of one new tire is $84. what would be the total cost including 7% tax for new tires for all five cars?
*July 5, 2012*

**math**

what is the simple interest of $1500.00 for 4 months at 63/4% annual interest?
*July 5, 2012*

**math**

4(2x + 3x)=30, solve for x
*July 5, 2012*

**math**

a parking lot charges 1.50 for the first hour of parking and 55 cents for each additional half hour. How much would it cost to park a car from 12:45 pm to 6:15 pm
*July 5, 2012*

**math**

If a contractor pays an average wage of $20.00 per hour and wants to make a 15% mark-up on the cost of labour, what will the contractor charge as an average labour cost on contracts?
*July 5, 2012*

**math**

A rectangular school yard 280 m by 245 m is to be fenced. How many metres of fencing will be required to fence it completely?
*July 5, 2012*

**Physics calculus based**

Consider the Sun to be at the origin of an xy-coordinate system. A telescope spots an asteroid in the xy-plane at a position given by (x, y) with a velocity given by (vx, vy). [DATA: (x, y) = (3.3, 5.2) ×10^11 m; (vx, vy) = (-6.1, -4.0) ×10^3 m/s.] (A) What will ...
*June 19, 2012*

**Physics HELP**

An ultrasound transducer used to measure the speed of blood cells is oriented at an angle of 45 degrees to the direction of the blood flow. if the frequency of the sound emitted by the transducer is 1.5 Mhz and the doppler shift is 268Hz, calculate the speed of blood cells. ...
*June 15, 2012*

**Math (Probability)**

Hassan has a bag which contains 20 coloured discs. He randomly chose three discs from the bag and found that two were red and one was white. a) Based on this sample, how many of each coloured disc are in the bag? b) Hassan returned the three discs to the bag and then randomly ...
*June 10, 2012*

**Physics **

A tungsten target is struck by electrons that have been accelerated from rest through a 38.9-kV potential difference. Find the shortest wavelength of the radiation emitted.
*June 7, 2012*

**business**

Most are wrong.
*June 6, 2012*

**math**

I wanna say 433 seats? but idk if i did that correctly...?
*May 22, 2012*

**math**

another type of percents im havin trouble with, i know im close to figuring it out but cant quite get there... "there were 130 people in a school auditorium to listen to a political candidate. This reprsents 33 1/3% of the capacity of the auditorium. How many seats are in...
*May 22, 2012*

**math**

how did u turn 33 1/3% into decimal? and how would I solve 0.3333333x = 130? And i rly do appreciate the help, have a huge test in the morning
*May 22, 2012*

**math**

another type of percents im havin trouble with, i know im close to figuring it out but cant quite get there... "there were 130 people in a school auditorium to listen to a political candidate. This reprsents 33 1/3% of the capacity of the auditorium. How many seats are in...
*May 22, 2012*

**math**

Thanks :D i knew it was 30, just wasn't sure how to get to the answer :D
*May 22, 2012*

**math**

Lois got 27 problems right on a math test. If this is 90% of the test, how many problems were on the test?
*May 22, 2012*

**math**

On a loan of $3,500, Manny had to pay $280 interest. The Interest was what percent of Manny's loan?
*May 22, 2012*

**Math**

Mr Gopal left 3/10 of his fortune to his wife. Of the remainder, 1/10 was donated to charity and the rest was distributed among his 4 children , A , B , C and D in the ratio of 4:3:3:2 . If $63000 was given to charity, calculate (a)the amount received by A (b)the total fortune...
*May 18, 2012*

**Physics**

When light of wavelength 391 nm falls on a potassium surface, electrons are emitted that have a maximum kinetic energy of 1.72 eV. 1) What is the cutoﬀ wavelength of potassium? Answer in units of nm 2)What is the threshold frequency for potassium? Answer in units of Hz ...
*May 11, 2012*

**Algebra 2**

Evaluate little 9 C little 9
*May 11, 2012*

**english**

Yeah, I've googled for ideas already, but most of them are the same controversial topics.
*May 10, 2012*

**english**

What is a good non-controversial topic for a senior research powerpoint? I need to do a research presentation answering a question (thesis). The rules are pretty lenient, so it can be about almost anything but there must be citations from books and articles. It can be ...
*May 10, 2012*

**PHYSICS Help please!!**

The two-mile linear accelerator at Stanford University in California "appears" to be less than a meter long to the electrons that travel in it. Explain.
*May 9, 2012*

**chemistry**

how much heat is needed to convert 30 g of water at 10 C to 110 C
*May 3, 2012*

**math**

Expand as a binomial series and simplify (2x + y^3)^5
*May 2, 2012*

**math**

Simplify the following expression 8!/4!
*April 30, 2012*

**physics**

That makes so much more sense! Thanks so much!!!
*April 22, 2012*

**physics**

It was wrong and I still dont get how to do it!
*April 22, 2012*

**physics**

Using the Bohr model, estimate the wavelength ë of the Ká characteristic X-ray for a metal an atom of which contains Z = 50 protons.
*April 22, 2012*

**physics help!**

Using the Bohr model, estimate the wavelength ë of the Ká characteristic X-ray for a metal an atom of which contains Z = 50 protons.
*April 22, 2012*

**physics**

The Kâ characteristic X-ray line for tungsten has a wavelength of 1.94 10-11 m. What is the difference in energy between the two energy levels that give rise to this line? Express this in each of the following units. (a) joules (b) electron volts
*April 22, 2012*

**physics**

A particle has a de Broglie wavelength of 3.30 10-10 m. Then its kinetic energy quadruples. What is the particle's new de Broglie wavelength, assuming that relativistic effects can be ignored?
*April 22, 2012*

**physics**

The Kâ characteristic X-ray line for tungsten has a wavelength of 1.94 10-11 m. What is the difference in energy between the two energy levels that give rise to this line? Express this in each of the following units. (a) joules (b) electron volts
*April 22, 2012*

**change decimal to fraction**

0.31 as a fraction idk
*April 18, 2012*

**Calculus, Related Rates**

A particle at point A is 50 mm away from a second particle at point B. The first particle is moving toward point B at a constant rate and the second particle is moving at a right angle to the line AB at a rate that is 1/3 of the rate of the first particle. The particles get ...
*April 17, 2012*

**Statistics**

A private medical clinic wants to estimate the true mean annual income of its patients. The clinic needs to be within $100 of the true mean. The clinic estimates that the true population standard deviation is around $2,100. If the confidence level is 95%, find the required ...
*April 15, 2012*

**Lab Math/Statistics**

The 95% confidence interval for a quality control specimen is 9.2-10.2 mg/dl. My question is, how do I figure out the coefficient of variation (%CV) with only this information?
*April 13, 2012*

**Math**

How would I determine if a set of numbers if Gaussian or non Gaussian?
*April 13, 2012*

**Phys**

What is the speed of a wave whose frequency is 9.00Hz and wavelength is 0.654 m?
*April 12, 2012*

**crjs101**

how to present the processing requirements and the mandated pretrial measures required by law.
*April 11, 2012*

**physics**

Some hydrogen occupies 120 ft at 60.0°F. Find the temperature when its volume is 132ft^3 if the pressure remains constant.
*April 11, 2012*

**chemistry**

Bill prepared 5.00-mL of borax solution at 59.2degrees C. He diluted the solution in an Erlenmeyer flask and titrated it to an endpoint with 27.05 mL of 0.500 M HCl. What is the saturation concentration of borate ions? I don't know what to do here. Does it involve a Ksp? ...
*April 9, 2012*

**Math**

Given P(x) = x^3 - 3x^2 - 5x + 10 a evaluate P9x) for each integer value of x from -3 through 5 b. Find all zeros of P(x) d. Prove that 5 is an upper bound on the zeros of P(x)
*April 9, 2012*

**Algebra**

solve: (1/(x-10)+(1/20)=(1/(20(x^2-100))
*April 8, 2012*

**Algebra**

((k^2+6k+9)/(k^2+12k+27))×(k^2+9)/((k^2+12k+27)) express in lowest terms
*April 7, 2012*

**Interediate algebra**

if f varies jointly as q^2 and h, and if f = 72 when q = 3 and h = 4, find h when f = 48 and q = 2
*April 7, 2012*

**Government**

In which type of colony did strict governors anger the colonists?
*April 3, 2012*

**english**

k and what about the others?
*April 3, 2012*

**english**

alright and 4) the infinitive phrase is a adverb?
*April 3, 2012*

**english**

the infinitive phrase in number 5)a noun?
*April 3, 2012*

**english**

i don't know how to identify the infinitive phase
*April 3, 2012*

**english**

what is the function of the italicized infinitive phrase in these sentences? 1)May I have permission to use the car tonight? 2)He went to Europe to study architecture. 3)Can you give me a place to put my things? 4)I want to go with you to the store. 5)To help you is my ...
*April 3, 2012*

**english**

cause i don't know this stuff that much
*April 3, 2012*

**english**

would it be the subject?
*April 3, 2012*

**english**

so in the second one 2)Brett earns his income by repairing cars. the gerund phrase is =by repairing cars and the function is= direct object?
*April 3, 2012*

**english**

what is the Gerund phrase and Noun function in these sentences? 1)Writing a research paper sounds difficult. 2)He must like studying calculus. 3)Her favorite pastime is entertaining friends. 4)Water skiing, sailing, and swimming are my favorite summer sports. 5)I enjoy playing...
*April 3, 2012*

**Phys**

A Brass rod 50.0 cm long expands 0.0734 cm when heated. Find the temperature change.
*April 2, 2012*

**Chemistry**

I went (dP/dT)fusion=deltaSm(fusion)/deltaVm(fusion) =deltaHm(fusion)/Tfusionm(1/pliq. - 1/psolid) =-140 barK^-1 So then deltaT=-deltaP/140 What is L? volume (litres?)
*March 29, 2012*

**Chemistry**

The normal melting point of H2O is 273.15 K, and deltaH fusion is 6010 J/mol. Calculate the change in the normal melting point at 175 and 625 bar assuming that the density of the liquid and solid phases remains constant at 997 and 917 kg/m^3 respectively. Explain the sign of ...
*March 29, 2012*

**Chemistry**

How many grams of lead(ii)iodide are generated when 400.0ml of 1.25M NaI reacts with 525.0ml of 1.00M Pb(NO3)2 according to the following balanced equeation? 2NaI + Pb(NO3)2---> 2NaNO3 + PbI2
*March 29, 2012*

**Biology**

Where is the Barnacle zone located in a rock platform ecosystem(Upper littoral, upper mid-littoral, lower mid-littoral or lower littoral zone)?
*March 29, 2012*

**Chemistry**

pH of 10^-3M HAc and 10^-2M NH4Cl in aqueous solution?? Do you just figure out each [H+] concentration separately and then add them??
*March 22, 2012*

**physics**

A short box with a large flat base is made of iron. The box has mass mI = 890 kg and specific heat cI = 450 J/kg◦C. The box is filled with water. The water has mass mW = 1220 kg and specific heat cW = 4180 J/kg◦C. The box and water are initially at temperature T0...
*March 14, 2012*

**Alg. 2**

3x-2/12 - 1/6 = 1/6 Please help me to solve.
*March 12, 2012*

**US History **

Why did many progressives of both major parties saw American entry into World War I as a peerless opportunity? Many Progressives during the First World War, Republican and Democrat alike, realized something of great importance to furthering their goals: they saw that the ...
*March 11, 2012*

**US History Since 1876**

How is the KKK and the Universal Negro Improvement Association the same? I am having trouble with coming up with reasons on how they were the same. I have several different reason's why they are not but I need help with this please!!
*March 10, 2012*

**english 11**

1. In persuasive writing, it is important to (1 point)anticipate and address counterarguments. clearly state your position. provide facts and examples to back up your position. practice all of the above. 2. “Redskin” was originally a term for (1 point)Indians in ...
*March 9, 2012*

**US History Since 1876**

WW 1 WWI ended with the Americans only seeing very little action. Its clear that the brunt of the fighting in the West was taken by the British Empire/Commonwealth and the French. The Bolshevik Revolution in Russia gave Germany the opportunity to wage the war on one front. ...
*March 3, 2012*

**US History Since 1876**

Did the United States win the war for the Allied Powers? Discuss the American contribution to the war effort and evaluate its significance.
*March 3, 2012*

**statistics**

Assume that the class has 60 students and that the examination period is 90 minutes in length. How many students do you expect will be unable to complete the exam in the alloted time?
*March 3, 2012*

**Math**

1. The manager of a bottle shop makes 25% profit on the cost price of all bottles of wine sold in the shop. She charges $12 for a bottle of Open View reisling. A hotel room service charged $30 for a similar bottle of Open View reisling. a) How much profit does the hotel room ...
*February 28, 2012*

**Math**

Transform the equation by completing the square: 4x^2 + y^2 - 8x + 6y -3 =0 Also show foci
*February 27, 2012*

**Physics**

A 2 kg clay ball traveling left to right at a speed of 6 m/s strikes and sticks to a 10 kg ball at rest. What is the fractional loss of kinetic energy after collision?
*February 21, 2012*

**Science**

B)Water is constantly evaporating over the ocean surface especially at the equator due to no seasonal loss in sun intensity.
*February 21, 2012*

**Math**

1. Is it more appropriate to use scientific notation for approximates or exact numbers? why? 2. In one plantation, there are 2700 young trees correct to 2 significant figures. In the other there are 830 full grown trees, correct to 2 significant figures. a) Why is it incorrect...
*February 21, 2012*

**math**

Show that the following data could not possibly be fit by an exponential function x y 3 72 5 200 7 392
*February 20, 2012*

**math**

200(1.025)^((n+1)*2) = 200(1.03)^(2n) 2(n+1)ln1.025 = 2nln1.03 (n+1)ln1.025 = nln1.03 n(ln 1.03 - ln1.025) = ln1.025 n = 5.074 years year 2006, month January
*February 19, 2012*

**Physics**

Two circuits (the figure below) are constructed using identical, ideal batteries (emf = E ) and identical lightbulbs (resistance = R). If each bulb in circuit 1 dissipates 4.00 W of power, how much power does each bulb in circuit 2 dissipate? Ignore changes in the resistance ...
*February 16, 2012*

**Physics**

About 5.12 x 104 m above Earth's surface, the atmosphere is sufficiently ionized that it behaves as a conductor. The Earth and the ionosphere form a giant spherical capacitor, with the lower atmosphere acting as a leaky dielectric. Find the capacitance C of the Earth-...
*February 16, 2012*

**Physics**

Two circuits (the figure below) are constructed using identical, ideal batteries (emf = E ) and identical lightbulbs (resistance = R). If each bulb in circuit 1 dissipates 4.00 W of power, how much power does each bulb in circuit 2 dissipate? Ignore changes in the resistance ...
*February 16, 2012*

**Physics**

Where do you get 10^6 m/s? So is the answer 22.5 or 225,000,000
*February 15, 2012*

**Physics**

Comic-strip hero Superman meets an asteroid in outer space, and hurls it at 750 m/s, as fast as a bullet. The asteroid is three thousand times more massive than Superman. In the strip, Superman is seen at rest after the throw. Taking physics into account, what would be his ...
*February 15, 2012*

**phi 103**

All dogs hate cats. Sirius is a dog. So Sirius hates cats" is an example of a
*February 12, 2012*

**Biology**

How are soldier crabs useful to us and what things are humans doing to wipe them out?
*February 12, 2012*

**Math**

We are currently studying "earning money" for math. I read this sentence: When a store claculates its profit as a percentage of its cost price the profit is always bigger than the profit calculated as a percentage of the selling price. What does it mean and please ...
*February 10, 2012*

**Physics**

An aluminum wire of diameter 2.47 mm carries a current of 12.9 A. How long on average does it take an electron to move 10.5 m along the wire? Assume 3.50 conduction electrons per aluminum atom. The mass density of aluminum is 2.70 g/cm3 and its atomic mass is 27.0 g/mol.
*February 10, 2012*

**Physics**

A silver wire and a platinum wire of the same length have the same resistance. What is the ratio of the diameter of the silver wire to that of the platinum wire. I did 10.6E-8/1.59E-8 but am not getting correct answer?
*February 10, 2012*

**Physics**

A silver wire and a platinum wire of the same length have the same resistance. What is the ratio of the diameter of the silver wire to that of the platinum wire.
*February 9, 2012*