Monday

August 3, 2015

August 3, 2015

Total # Posts: 742

**physics**

A boy is pushing his sled up a snowy slope. The sled has a mass of 20.4 kg and weighs 200 N. The boy pushes with a constant force of 75 N. The sled travels a distance of 10 m and gains 3 m in height. When the sled reaches the top, it is traveling 2 m/s. What is the efficiency ...
*March 27, 2013*

**Statistics**

A pharmaceutical company claims its new medication relieves painful symptoms caused by tension headaches within 15 minutes. To investigate this claim, a local health clinic conducts a study of 45 patients who suffer from chronic tension headaches. Each patient is given ...
*March 26, 2013*

**Statistics**

According to a recent pole only 21% of Americans were satisfied with the direction the U.S. is heading. To investigate the reliability of the report an independent polling organization surveyed 500 Americans and inquired as to whether or not they were satisfied with the way ...
*March 26, 2013*

**Statistics**

Assume the weights of men are normally distributed having a mean of 185 lbs and a standard deviation of 17 pounds. A. Calculate the probability a randomly selected man weights less than 225 lbs B. Approximately 72% of men’s weights exceed how many pounds. C. In a random ...
*March 26, 2013*

**Statistics**

Assume the wait time to see a cardiologist at a certain clinic are uniformly distributed between 7 minutes and 23 minutes. Calculate the probability a randomly selected patient waits at least 18 minutes to see the cardiologist. The random variable, Z, is associated with a ...
*March 26, 2013*

**Statistics**

A Manufacturer of torque converters claim only 1% of them are defective. A. Calculate the Mean number of defective converters in a shipment of 500 converters. B. Calculate the standard deviation in the defective torque converters in a shipment of 500 converters. C. Would it be...
*March 26, 2013*

**Statistics**

A Manufacturer of torque converters claim only 1% of them are defective. A. In a shipment of 12 torque converters calculate the probability exactly 2 converters are defective. B. In a shipment of 35 converters, calculate the probability at least 1 converter is defective.
*March 26, 2013*

**Statistics**

In a certain game of chance a person pays $5 to play a game. A person randomly selects 2 integers ranging from 0-99. The host of the game then uses a random number generator to select 2 integers ranging from 0-99. If the players values and hosts values agree (in any order), ...
*March 26, 2013*

**Statistics**

Use this information to calculate the mean and standard deviation of this random variable. P(x)- .25, .05, .55, .15
*March 26, 2013*

**Statistics**

A standard deck of 52 playing cards is composed of 4 suits. Each mix contains 13 cards. Jacks, Queens, and Kings are considered face cards. Assume three cards are selected without replacement. Calculate the probability of drawing two hearts, followed by a spade.
*March 26, 2013*

**Chemistry**

A solution is prepared by dissolving 571.6 g of H 2SO4 in enough water to make 1000.0 mL of solution. The solution has a density of 1.3294 g/mL. (molar mass of H2SO4 = 98.08). What is the molar concentration of the solution?
*March 24, 2013*

**chemistry**

What mass of F2 is needed to produce 116 g of PF3 if the reaction has a 77.4% yield?
*March 10, 2013*

**Pre-calculus**

Use this equation. X=t*v*cos(theta) So 2*102*cos67=79.70915021
*February 19, 2013*

**Pre-calculus**

79.70915021
*February 19, 2013*

**Statistics**

In order to compare two kinds of feed, thirteen pigs are split into two groups, and each group received one feed. The following are the gains in weight (kilograms) after a fixed period of time: Feed A: 8.0 7.4 5.8 6.2 8.8 9.5 Feed B: 12.0 18.2 8.0 9.6 8.2 9.9 10.3 We wish to ...
*February 18, 2013*

**World history**

Confucius believed that human beings are essentially A. gods. B. evil. C. good. D. sinful.
*February 9, 2013*

**chemistry**

What has the higher normal melting point: CHI3 or CHF3? The answer in the book is CHI3. So I'm assuming the answer is CHI3 because Iodine is the bigger and will form larger london dispersion forces, but isn't a stronger dipole moment formed in CHF3 because fluorine is ...
*January 16, 2013*

**Physics conceptual questions**

You have a drink that you want to cool off? You could put in 100 g of ice or 100 g of water, both at 0 degree C. Which one would be more effective in cooling your drink? Why?
*January 14, 2013*

**Math**

Show that (a^2+b^2)(c^2+d^2)=(ac+bd)^2 + (ad-bc)^2
*January 11, 2013*

**Math**

Show that (a^2+b^2)(c^2+d^2)=(ac+bd)^2 + (ad-bc)^2
*January 11, 2013*

**Math**

Show that (a^2+b^2)(c^2+d^2)=(ac+bd)^2 + (ad-bc)^2
*January 11, 2013*

**Math**

9/10?
*January 10, 2013*

**SCIENCE -HELP!!**

How does the discovery of seafloor spreading help to explain the mechanism behind why plates move??
*January 8, 2013*

**Math**

If 1 and –6 are two of the roots of 6x^4 + 31 x^3 − 33x^2 − 16x + 12, then what are the other two? A. 2 and 3/2 B. -1 and 6 C. 1/2 and -2/3 D. -2 and 2/3
*December 14, 2012*

**algerbra**

If 1 and –6 are two of the roots of 6x^4 + 31 x^3 − 33x^2 − 16x + 12, then what are the other two? A. 2 and 3/2 B. -1 and 6 C. 1/2 and -2/3 D. -2 and 2/3
*December 14, 2012*

**Physics**

21) A 46 kg skater is standing still in front of a wall. By pushing against the wall she propels herself backward with a velocity of – 1.2 m /s. Her hands are in contact with the wall for 0.8 s. Ignore friction and wind resistance • Find the magnitude and direction ...
*December 4, 2012*

**Physics**

A 4 ohm resistor and 10 ohm resistor are connected in series. If this circuit is connected to a 12 V battery, how much current will flow through the circuit?
*December 4, 2012*

**college algebra--please help**

What percent of the total population is found between the mean and a z-score of -0.50?
*November 19, 2012*

**Science**

Intensity of the HeNe laser (lambda = 632nm) was measured at 2 distances: 1m and 200m from the laser. The meter reading was 10W and 1W correspondingly. How many photons/sec will enter your eye if you look into the laser from 1m? From 2m? Assume that radius of the pupil was 2....
*November 14, 2012*

**Algebra 2**

Plan A charges $5 per minute plus a one time monthly fee of $75 and plan B charges $7 per minute, plus a one time monthly fee of $25. After how many minutes will the total cost of the two equations be the same?
*November 13, 2012*

**Binomial Probability**

Before 1918, wolves were shown as 55% male, 45% female. From 1918 to present they were shown as 70% male and 30% female. In a random sample of 12 wolves, what was the probability that 6 were male? What was the probibility that 6 or more were female? What was the probability ...
*November 10, 2012*

**Sociology**

In the twentieth centruy, which country had a caste system based on race? a. India b. the USA c. South Africa d. a and b only e. b and c only
*October 29, 2012*

**Chemistry**

What does 3p have?
*October 28, 2012*

**HELP ASAP**

I need help asap!
*October 28, 2012*

**Chemistry**

What quantum numbers specify these subshells? 2s n= l= 3p n= t= 6d n= l=
*October 28, 2012*

**Chemistry**

Thanks it was correct!
*October 28, 2012*

**HELP ASAP**

I need help asap!
*October 28, 2012*

**Chemistry**

What element forms an ion with an electronic configuration of [Xe] and a –2 charge?
*October 28, 2012*

**NEED HELP**

Is it Argon?
*October 28, 2012*

**Chemistry**

Metals lose electrons under certain conditions to attain a noble-gas electron configuration. How many electrons must be lost by the element Ca? Is it 2 e^-? Which noble-gas electron configuration is attained in this process? argon radon krypton xenon helium neon
*October 28, 2012*

**Chemistry**

Assuming that the smallest measurable wavelength in an experiment is 0.330 fm (femtometers), what is the maximum mass of an object traveling at 157 m·s^–1 for which the de Broglie wavelength is observable? mass = ? kg
*October 28, 2012*

**College Chemistry**

What volume of the solution in 5a would be necessary to react completely with 23.00mL of 0.549M NH3 according to the equation: NiSO4+6NH3 -> [Ni(NH3)6]SO4 The molarity of ta is 1.667 x 10^-4M
*October 25, 2012*

**Calculus**

What is the point of inflection of the function f(x)=x^3-8x^2+5x+50? Is the local extrema at f(1/3)=50.8 max and f(5)=0 min? For the second derivative I got f(x)=6x-16 and then got x=16/6 when set to zero.
*October 24, 2012*

**Chemisty HELP ASAP**

In this problem, your answers should be mathematical expressions involving a variable. Consider an ideal gas with an absolute temperature of T1 To what temperature would you need to heat the gas to double its pressure? T2=? I got T2=2P but it is wrong
*October 17, 2012*

**Chemistry**

It is 65.4g/mol
*October 17, 2012*

**Chemistry**

P=.995atm V=.205L n=? R=.0821 Lxatm/molxk) T=298K
*October 17, 2012*

**Chemistry**

n=.0833 mols molar mass=(.0833mols/.528g)=.158g/mol
*October 17, 2012*

**Chemistry**

A 0.528 gram sample of a metal, M, reacts completely with sulfuric acid according to: M+H2SO4 -> MSO4+H2 A volume of 205 mL of hydrogen is collected over water; the water level in the collecting vessel is the same as the outside level. Atmospheric pressure is 756.0 Torr and...
*October 17, 2012*

**Chemistry**

T2=?
*October 17, 2012*

**Chemistry**

In this problem, your answers should be mathematical expressions involving a variable. Consider an ideal gas with an absolute temperature of T1 To what temperature would you need to heat the gas to double its pressure? T2=? I got T2=T1P times 2 but it is wrong
*October 17, 2012*

**Chemistry Answer?**

Is the answer 3.24x10^-3 g/mol?
*October 16, 2012*

**Chemistry**

A 0.528 gram sample of a metal, M, reacts completely with sulfuric acid according to: M+H2SO4 -> MSO4+H2 A volume of 205 mL of hydrogen is collected over water; the water level in the collecting vessel is the same as the outside level. Atmospheric pressure is 756.0 Torr and...
*October 16, 2012*

**Chemistry**

T1 is 288K but what is T2?
*October 16, 2012*

**Chemistry**

2.05 g of an unknown gas at 45 °C and 1.00 atm is stored in a 1.15-L flask. What is the density of the gas?
*October 16, 2012*

**Chemistry**

At a certain temperature and pressure, one liter of CO2 gas weighs 1.45 g. What is the mass of one liter of C4H10 gas at the same temperature and pressure?
*October 16, 2012*

**Chemistry**

Is the answer 1.85x10^6 L?
*October 16, 2012*

**Chemistry**

A hot air balloon is filled with 1.39 × 106 L of an ideal gas on a cool morning (11 °C). The air is heated to 105 °C. What is the volume of the air in the balloon after it is heated? Assume that none of the gas escapes from the balloon.
*October 16, 2012*

**Chemistry**

An ideal gas is allowed to expand from 6.00 L to 45.0 L at constant temperature. By what factor does the volume increase? ? Number The pressure will Increase by that factor or decrease by that factor? If the initial pressure was 105 atm, what is the final pressure?
*October 16, 2012*

**Math HELPPP**

In a survey of 2000 adults 50 years and older of whom 40% were retired and 60% were pre-retired, the following question was asked: Do you expect your income needs to vary from year to year in retirement? Of those who were retired, 33% answered no, and 67% answered yes. Of ...
*October 16, 2012*

**Calculus**

What is the derivative of 7e^(3sin^(4x+5))?
*October 16, 2012*

**Calculus**

What is the derivative of 2^(5x)tan(x^2)
*October 16, 2012*

**Calculus**

What is the derivative of sin(3x+1)^4?
*October 15, 2012*

**Calculus**

Find dy/dx using implicit differentiation of xy + sin^2y=10350. Is it -y/(x+2siny)
*October 15, 2012*

**Calculus**

Dervative of cos(x) is -sin(x) so it would be negative.
*October 15, 2012*

**Math**

How do you solve this equation; There are 128 7th graders at Mark's school, if there are 16 more girls than boys, how many 7th grade boys are there?
*October 13, 2012*

**Physics**

From the window of a building, a ball is tossed from a height y0 above the ground with an initial velocity of 9.40 m/s and angle of 23.0° below the horizontal. It strikes the ground 5.00 s later. By how much does the ball clear or fall short (vertically) of clearing the ...
*October 12, 2012*

**Physics**

From the window of a building, a ball is tossed from a height y0 above the ground with an initial velocity of 9.40 m/s and angle of 23.0° below the horizontal. It strikes the ground 5.00 s later. By how much does the ball clear or fall short (vertically) of clearing the ...
*October 12, 2012*

**writing (persuasive essay)**

Hi. I'm in 10th grade and our teacher assigned us a persuasive essay to write in class over a topic that we debated about for the last two weeks. Every team had a different topics (mine was school should start from 11 am. to 5 pm), but now we're going to write a ...
*October 7, 2012*

**math**

write 718.5 in scientific notation
*October 6, 2012*

**Physics**

A swimmer, capable of swimming at a speed of 0.8 m/s in still water (i.e., the swimmer can swim with a speed of 0.8 m/s relative to the water), starts to swim directly across a 2.5 km wide river. However, the current is 0.91 m/s, and it carries the swimmer downstream.
*September 25, 2012*

**6th grade math**

the answer is 15 because nothing inside the lines can be negitive
*September 23, 2012*

**english**

what word do these letters make
*September 18, 2012*

**algebra**

a rectangle has a length of 17 inches more than twice its height. If the perimeter of a rectangle is 304 inches, find its dimensions.
*September 15, 2012*

**Computers**

double **dptr; dptr = new double*[5]; for (int i = 0; i < 5; i++) dptr[i] = new double[3]; How many rows and columns will there be in dptr? Also, what would the code look like to Delete all the space allocated for dptr???
*August 31, 2012*

**geometry**

If EF=10x+12,FG=14,and EG=136, find the value of x.
*August 29, 2012*

**biology**

1234
*August 9, 2012*

**world literature**

Do your own homework or ask the teacher for help!
*July 25, 2012*

**Chemistry II**

43.4
*July 17, 2012*

**chemistry**

An ice cube of mass 10g at -10C is added to the beaker containing 150mL of water at 88.5C. Assuming no heat is lost to the surrounding; calculate the equilibrium temperature for the liquid after the ice melts.(Heat of fusion for H2O = 6.01 kJ/mol. Heat of vaporization 40.67kJ/...
*June 21, 2012*

**chemistry**

What volume of LR(Lactated Ringer's) solution would be required to make 1.0L of a solution that was .050M in chloride ion?
*June 12, 2012*

**Math**

The state of texas covers approxmiately 268,581 squared mi. During a hail storm the entire state is covered in 1billion meters of hail.(average radius of 1.4292cm)assume the hail falls so that the gaps of air are limited to 26% of the volume. As the state begins to warm, the ...
*June 7, 2012*

**chemistry**

268,581*** squared miles
*June 6, 2012*

**chemistry**

The state of texas covers approxmiately 268,58 squared mi. During a hail storm the entire state is covered in 1billion meters of hail.(average radius of 1.4292cm)assume the hail falls so that the gaps of air are limited to 26% of the volume. As the state begins to warm, the ...
*June 6, 2012*

**Physics**

Awesome, thanks Elena!
*May 31, 2012*

**Physics**

Calculate the force on an electron (qe = -1.6 x 10^-19 C) in each of the following situations: a.) moving at 2.0% the speed of light and perpendicular to a 3.0 T magnetic field b.) 3.0 x 10^-6 m from a proton c.) in Earth's gravitational field at the surface of Earth
*May 31, 2012*

**Physics**

oops accidentally posted twice... sorry.
*May 31, 2012*

**Physics**

Calculate the force on an electron (qe = -1.6 x 10-19 C) in each of the following situations: a.) moving at 2.0% the speed of light and perpendicular to a 3.0 T magnetic field b.) 3.0 x 10-6 m from a proton c.) in Earth's gravitational field at the surface of Earth
*May 31, 2012*

**math**

An object travelling in a straight line away from a motion sensor at a constant rate moves from 4 m away to 16 m away between t = 1 s and t = 6 s. Describe the segment corresponding to this walk on the speed versus time graph.
*May 30, 2012*

**math**

(2,-7) is a point on the graph of y=f(x) . Find the corresponding point on the graph of y= 3f(5(x-1)+1 .
*May 30, 2012*

**chemistry**

A sample of a saturated hydrocarbon is placed in a 1.0L vessel at 107oC. The pressure of the sample at these conditions is .40 atm. A stoichiometrically equivalent amount of oxygen is added to the vessel and the mixture is combusted. Following combustion, the pressure in the ...
*May 22, 2012*

**chemistry**

it isn't showing your response in the earlier post!
*May 22, 2012*

**chemistry**

A 20.0 gram sample is a mixture of sodium phosphate ,sodium mono-hydrogen phosphate,sodium dihydrogen phosphate and sodium chloride. The sample is dissolved in 100.0 ml of deionized water and titrated with 1.5 M hydrochloric acid. The initial pH of the solution is pH= 12.9. ...
*May 22, 2012*

**chemistry**

A 20.0 gram sample is a mixture of sodium phosphate ,sodium mono-hydrogen phosphate,sodium dihydrogen phosphate and sodium chloride. The sample is dissolved in 100.0 ml of deionized water and titrated with 1.5 M hydrochloric acid. The initial pH of the solution is pH= 12.9. ...
*May 22, 2012*

**Honors Chemistry**

This is a few of my final review questions. I basically just need to know the steps for each one because my teacher doesn't explain them very well. I would really appreciate some help.
*May 21, 2012*

**Honors Chemistry **

1. .0025 M tartaric acid completely reacts with .0030 M of Al bicarbonate if .913 l of CO2 forms at 298 Kelvin with pressure of 1.4 ATM how much base used? 2. 3.1 x 10^23 molecules of .0035 M hydriodic acid reacts with 25 grams of magnesium bicarbonate how much carbon dioxide ...
*May 21, 2012*

**math**

m=4;(3,2)
*May 10, 2012*

**math**

Managers should consider ethical aspects of their decisions because:
*May 5, 2012*

**chemistry**

heeeeellppppppp
*May 4, 2012*