Saturday

December 10, 2016
Total # Posts: 1,322

**physics**

What is the speed of sound in a medium where a 100-kHz frequency produces a 5.96-cm wavelength?

*November 27, 2012*

**physics**

What is the sound intensity level in decibels of ultrasound of intensity 10^5 W/m2, used to pulverize tissue during surgery

*November 27, 2012*

**physics**

What sound intensity level in dB is produced by earphones that create an intensity of 4.00¡¿10^-2 W/m^2?

*November 27, 2012*

**physics**

What is the intensity in watts per meter squared of 85.0 db sound?

*November 27, 2012*

**Social studies**

what was the formal name for our country?

*November 27, 2012*

**physics**

The pendulum on a cuckoo clock is 5.00 cm long. (a) Determine the period of this pendulum. (b) What is its frequency?

*November 20, 2012*

**physics**

What mass on a spring with a spring constant of 120 N/m will oscillate with a period of 1.0 s?

*November 20, 2012*

**physics**

A force of 85 N is required to compress the spring by 0.0200 m. How much force is needed to compress the spring by 0.0600 N? 3.

*November 20, 2012*

**physics**

A 4.5-kg block is hung from a spring causing the spring to elongate 12 cm. With what period will the spring oscillate if the spring was stretched 15 cm and released?

*November 20, 2012*

**Science**

What is the Frosted Eflin's role in the food chain?

*November 18, 2012*

**science**

A bullet with a mass of 7.11 g and a speed of 774 m/s penetrates a tree horizontally to a depth of 1.85 cm. Assume that a constant frictional force stops the bullet. Calculate the magnitude of this frictional force. Try energy considerations. Answer in units of N

*November 16, 2012*

**science**

An outfielder throws a 1.88 kg baseball at a speed of 57 m/s and an initial angle of 10.2. What is the kinetic energy of the ball at the highest point of its motion? Answer in units of J

*November 16, 2012*

**science**

It takes 3.38 J of work to stretch a Hooke’s-law spring 5.63 cm from its unstressed length. How much the extra work is required to stretch it an additional 4.22 cm? Answer in units of J

*November 16, 2012*

**physics**

The equation of motion for an oscillator is given by y= (0.200cm)sin (140t). What are the 1)amplitude 2)period, and 3)frequency of this motion?

*November 14, 2012*

**physics**

The equation of motion for an oscillator is given by y= (0.200cm)sin (140t). What are the 1)alplitude, 2)period, and 3) frequency of this motion?

*November 14, 2012*

**calculus**

An auditorium with a flat floor has a large screen on one wall. The lower edge of the screen is 3 feet above eye level and the upper edge is 10 feet above eye level. Assume you walk away fron the screen at a rate of 3 ft/s while looking at the screen. What is the rate of ...

*November 13, 2012*

**physics**

Radio waves transmitted through space at 3.00¡¿10 8 m/s by the Voyager spacecraft have a wavelength of 0.120 m. What is their frequency?

*November 13, 2012*

**physics**

What is the wavelength of an earthquake that shakes you with a frequency of 10.0 Hz and gets to another city 84.0 km away in 12.0 s?

*November 13, 2012*

**physics**

Wind gusts create ripples on the ocean that have a wavelength of 5.00 cm and propagate at 2.00 m/s. What is their frequency?

*November 13, 2012*

**math**

Identify the two numbers left and 20 with the most factors

*November 7, 2012*

**Math**

The El Paso Middle School girls' basketball team is going from El Paso to San Antonio for the Texas state championship game. The trip will be 560 miles. Their bus travels at an average of 60 miles per hour. Estimate the distance the bus travels in 2 hours.

*October 28, 2012*

**math**

solve for x e^(2x+3) -7 = 0

*October 25, 2012*

**Chemistry**

A sample of CO2 gas in a syringe has a volume of 25.0 mL at 20.0 ºC. If you warm the gas in your hand to 37 ºC, what will be the final volume?

*October 25, 2012*

**physics**

2. Contrast the metric units of distance, time, and speed. Describe the relationship between them.

*October 23, 2012*

**Physics**

2. Contrast the metric units of distance, time, and speed. Describe the relationship between them.

*October 23, 2012*

**Physics**

The gravitational field strenght on the moon is 1.63N/kg. If a rock on the moon weights 2000N, how much does the same rock weigh on the earth?

*October 21, 2012*

**Math**

how do you break apart arrays?

*October 17, 2012*

**ant 101**

A “hope chest” is a form of: (Points : 1) *brideprice. bridewealth. dowry. brideservice.

*September 24, 2012*

**language arts**

The italicized words are "Listening to the mix CD my brother made for me".

*September 19, 2012*

**language arts**

I believe its D.

*September 19, 2012*

**math**

andre drove part of a 260km trip at 80kph and the rest at 100kph. find the distance he traveled at 80kph if his total driving time was 2h 30min

*September 17, 2012*

**math**

my number is 5 more than one-half my number. What is my number?

*September 17, 2012*

**6th grade math**

Simplest form of 0.8

*September 17, 2012*

**plz help ms sue**

the answers are 1. A 2.B 3.D 4.B hope this helps.

*September 13, 2012*

**Math**

#2 is wrong its b

*September 13, 2012*

**physics**

Acceleration is the change in velocity over time: Acceleration = (Final velocity - initial velocity)/time Since there are no directions involved, speed is used instead of velocity. So you know the initial speed: Initial speed = 53800 m/s And you know the final speed: Final ...

*September 11, 2012*

**MATH**

Just start at 2 and divide 255 which is (2^8)-1. 255/2 =127.5 Not divisible by 2. 255/3 = 85 We have one prime number, 3. 255/5 = 51 We have two prime numbers - 3,5. 255/7 = 36.43 Not divisible by 7 255/9 = 28.33 Not divisible by 9 255/11 = 23.18 Not divisible by 11 . . . 255/...

*September 11, 2012*

**MATH**

You have to break 1260 down into it's number tree. Start by dividing the number by 2 until you can't do it evenly, then divide by 3, and so on until no more divisions can be made: 1260/2 = 630 So we have one prime factor, 2 and are left with 630: 630/2 = 315 Now we ...

*September 11, 2012*

**MATH URGENT**

In either case though, you have to think. How many even or odd numbers are there between 1-100? The answer is 50. So in order to guarantee the removal of an even number 51 integers must be randomly removed.

*September 11, 2012*

**MATH URGENT**

You may have to clarify, do you mean how many times will this have to be done to guarantee the removal of an even or odd integer? Because just removing one integer guarantees the removal of an integer.

*September 11, 2012*

**IPC**

Again, we start with the question: What would the final speed of a car be after 5.0 seconds with a starting speed of 50 mi/hr? What is needed to solve this equation: Acceleration of the car. Yes that is all that is necessary. To find the acceleration, this is where the 0-60 mi...

*September 11, 2012*

**physics**

To answer this question first it helps to know the first ants speed as cm/s: 16 meters/second * 1000cm/m = 1600 cm/s Which means that the first ant will reach the end of the counter in .034 seconds. The second ant is traveling at 3.99999 cm/s which means it will reach the ...

*September 11, 2012*

**Math**

There is quite the easy shortcut for adding any set of numbers from 1 to whatever and that is this: (n(n+1))/2 So, let's say you wanted to find the sum of all numbers from 1 to 99. 99 will be n and so the equation will look like the following: (99(99+1))/2 Solve for the ...

*September 11, 2012*

**IPC**

You should approach this problem by gathering all of the information that is relevant to answering the question. The question is: Will the student make it to class in 5 seconds? What is needed to answer this question? Velocity of the student, and distance to the class room. ...

*September 11, 2012*

**chemistry**

Molality id defined as (moles of a solute)/(kg of solvent). So the concentration of Ca in the river water would be (13.4 mg/kg) * (1/1000 g/mg) * (1/40.078 mol/g) = 3.34 x 10^-4 mol/kg The key to solving any concentration problem is knowing what units you're starting with ...

*September 11, 2012*

**college biology**

If someone has abnormally low cholesterol levels then perhaps it is being consumed by processes that need cholesterol faster than it is being synthesized or brought in through the diet. Perhaps excess bile production, inability to use dietary cholesterol, excess steroid ...

*September 11, 2012*

**Chemistry**

A solution is made by dissolving 1.0 mole of Na2SO4(ionic compound) into water to get 1.0L of solution. Give the conc of all the ions present in solution in M?

*September 5, 2012*

**Math**

1. x/4 + 11 = -25 2. x/4 - 5 = 13 3. x/4 = 13

*September 4, 2012*

**chems**

A cubic piece of metal measures 7.50cm on each edge. If the metal is nickel, whose density is 8.90 {\rm g/cm}^3, what is the mass of the cube?

*September 3, 2012*

**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*

**medical billing/coding**

Add code 12032 for intermediate repair (closure)

*August 3, 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 don't 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*