Sunday

February 1, 2015

February 1, 2015

Total # Posts: 1,375

**linear algebra**

show that if L is any line through the origin in R3 and x is any vector with its initial point at the origin, then the reflection of x through the line l(acting as a mirror) is equal to 2(projection of x onto r)-x I don't know how to set this up. -x=2(projection of x onto ...
*January 24, 2011*

**marketing**

3M's main market for promoting this produc were college students. Their goal was to raise awareness of the Post-it flag highlighters within the the college community as much as possible. They used print ads in college newspapers and TV ads and relayed on word of mouth ...
*January 24, 2011*

**Physics**

A golf ball is chipped at an angle of 49 degrees and with a speed of 8.5 m/s. How far does it travel to the nearest tenth of a meter?
*January 23, 2011*

**chem**

At 20 degrees celsius the vapor pressure of dry ice is 56.5atm. If 10 g of dry ice (solid CO2) is placed in an evacuated 0.25 L chamber at a constant temperature of 20 degrees celsius, will all of the solid sublime? Is the answer no? I don't know if this is right, but I ...
*January 22, 2011*

**Chemistry**

What do I do when writing the net ionic equation for Magnesium nitrate reacted with sodium chloride? I've wrote out the molecular equation and the total ionic equation. Everything cancels out....under my total ionic equation do i just write no reaction? |thanks!
*January 19, 2011*

**physics**

two masses m' each are hanging with help of a light string,which passes over mass less pulley. mass A starts leaking out at a rate of u kg/s with velocity v' with respect to mass A. find kinetic energy of block B as a function of time.
*January 16, 2011*

**physics**

a student standing on the roof of a 50 meter high building kicks a stone at a horizontal speed of 4 meters per second, how much time is required for the stone to reach the level ground below?
*January 16, 2011*

**grammar**

Ok thanks, so there are only two avderbs in this entire paragraph?
*January 13, 2011*

**grammar**

Need to identify five adverbs in this paragraph. I think I am correct but would like a second opinion. Thanks for your thoughts. LITTLE FOCKERS is the “continued” (adverb) antics of Greg and Pam Focker (Ben Stiller and Teri Polo) who “now” (adverb) have two...
*January 13, 2011*

**nuclear engineering**

Determine the amount of energy required (in MeV) to dissociate the following elements into component parts (protons, neutrons and electrons) • Hydrogen • Deuterium • Tritium
*January 13, 2011*

**Math**

Solve the proportion for u. (u-2):(u+3) = 4:3
*January 12, 2011*

**math**

On the unit circle the coordinates of P(theta) are (0.588, 0.809). Find the coordinates of P(2theta). Please help.
*January 11, 2011*

**Math**

A sweepstakes posted the odds and payoffs. Suppose that mailing the sweepstakes costs $0.33 and the odds in favor of winning the various prizes are listed in the chart below. What is the expected value of the sweepstakes for any individual? Considering the postage, is the ...
*January 11, 2011*

**math**

Can the expression (r-3)(s+2) be simplified without knowing the values of r and s?
*January 10, 2011*

**math**

If the probability of an event happening is 1/7, what are the odds against it happening? What is the ratio of the odds against the event?
*January 10, 2011*

**Algebra**

Two questions? Build a patio-hypotenuese is 50 feet long the two sides of patio are same. What is the length of one side of the patio I think I set it up a^2 + b^2 = c^2 a^2 + b^2 = 50^2 a^2+ b^2 = 2500 then I just could say 2a^2 = 2500 a^2 = 2500/2 a^2 = 1250 sqrt of 1250 = ...
*January 5, 2011*

**Chemistry**

I've got 21.2L, but supposedly correct answer is 21.7L. How?
*December 13, 2010*

**Chemistry**

Given 20.0 L of ammonia gas at 5C and 730 torr, calculate the volume at 50C and 800 torr
*December 13, 2010*

**science**

Chapter 1 & 2 Review Questions 1. Compare and Contrast the two main branches of physical science. 2. Distinguish between scientific laws and scientific theories. 3. Describe the steps of the scientific method. 4. Explain the objective of a consistent system of units, and ...
*December 13, 2010*

**math**

if possible, change each comparison of concentrate to water into a ratio. If not, explain why. a. the mix is 60% concentrate. b. the fraction of the mix that is water is 3/5 c. the difference between the amount of concentrate and water is 4 cups
*December 7, 2010*

**accounting**

Does the flexible budget term mean A series of budgets for varying rates of activity?
*December 7, 2010*

**math**

if you have a apple juice mix of 5 cups concentrate to 8 cups water, if you only make 1 cup of mix, how much water and how much concentrate do you need?
*December 6, 2010*

**10th grade**

How many grams of cacl2 are in 4.3l solution of 2.8 m cacl2
*December 3, 2010*

**physics**

thank you so much!!!
*December 2, 2010*

**physics**

yes i understand A but in B it's increasing the speed at a rate (which means acceleration) of 1.45 m/s^2 and thats where i get lost
*December 2, 2010*

**physics**

(A.) A hawk flies in a horizontal arc of radius 13.4 m at a constant speed of 4.5 m/s. Find its centripetal acceleration. Answer in units of m/s2. (B.) It continues to fly along the same horizon- tal arc but increases its speed at the rate of 1.45 m/s2. Find the magnitude of ...
*December 2, 2010*

**physics**

(A.) A hawk flies in a horizontal arc of radius 13.4 m at a constant speed of 4.5 m/s. Find its centripetal acceleration. Answer in units of m/s2. (B.) It continues to fly along the same horizon- tal arc but increases its speed at the rate of 1.45 m/s2. Find the magnitude of ...
*December 2, 2010*

**physics**

Wouldn't it be zero. It's speed at the top and bottom are zero so...
*December 2, 2010*

**Earth Science**

Describe how Earth would be different today if it contained no radioactive material. What would the consequences be for the Earth’s interior layers?
*December 2, 2010*

**Physics**

When empty, a particular helicopter of mass 3770 kg can accelerate straight upward at a maximum acceleration of 1.29 m/s2. A careless crewman overloads the helicopter so that it is just unable to lift off. What is the mass of the cargo?
*November 28, 2010*

**chemistry**

thanks! that helped me solve the problems.
*November 27, 2010*

**chemistry**

i am doing problems for chemistry class, and some of them are Calculating square root/ Cube Root but some are 4 and 5 instead of 2 or 3. if in a problem the exponent is 4 or 5 how would i use my calculator to calculate the root?
*November 27, 2010*

**chemistry**

sorry, answer found. no longer need help..
*November 24, 2010*

**chemistry**

The pH of a solution that contains 0.818 M acetic acid (Ka = 1.76 x 10-5) and 0.172 M sodium acetate is __________. The Ka of acetic acid is 1.76 × 10-5.
*November 24, 2010*

**chemistry**

The pH of a solution that contains 0.818 M acetic acid (Ka = 1.76 x 10-5) and 0.172 M sodium acetate is __________. The Ka of acetic acid is 1.76 × 10-5.
*November 24, 2010*

**chemistry**

The pH of a solution that contains 0.818 M acetic acid (Ka = 1.76 x 10-5) and 0.172 M sodium acetate is __________. The Ka of acetic acid is 1.76 × 10-5.
*November 23, 2010*

**chemistry**

The solubility of lead (II) chloride (PbCl2) is 1.6 x 10^-2 M. What is the Ksp of PbCl2?
*November 22, 2010*

**Math**

A ramp of length 6, width 4, and height 2.
*November 21, 2010*

**Math**

Calculate the volume of the ramp in Figure 17 in three ways by integrating the area of the cross sections: (a) Perpendicular to the x-axis (rectangles) (b) Perpendicular to the y-axis (triangles) (c) Perpendicular to the z-axis (rectangles)
*November 21, 2010*

**physics**

A 1.0 m cubed object floats in fresh water with 20% of it above the waterline. What does the object weigh out of the water?
*November 21, 2010*

**Calculus**

Calculate the volume of the ramp in Figure 17 in three ways by integrating the area of the cross sections: (a) Perpendicular to the x-axis (rectangles) (b) Perpendicular to the y-axis (triangles) (c) Perpendicular to the z-axis (rectangles)
*November 21, 2010*

**Math**

60 miles. 4mph * 15 hours = 60 miles 20mph * 3 Hours = 60 miles
*November 21, 2010*

**science**

can a color blind female have a son that has normal vision? color blindness is caused by a sex linked recessive allele. N=normal vision n=color blind
*November 21, 2010*

**calculus**

2 - 6X
*November 21, 2010*

**PHYSICS**

A 0.181 kg mass is attached to a spring and executes simple harmonic motion with a pe-riod of 0.21 s. The total energy of the system is 1.2 J. Find the force constant of the spring. b) Find the amplitude of the motion.
*November 20, 2010*

**UNIVERSITY COMPOSITION AND COMMUNICATION I (AXIA) **

Students are often confused about the use of the words good and well in their writing. Write a 100-word passage to Susan Anker, the author of the course’s textbook, in which you describe five details from her book that are good and five details about the book that are ...
*November 17, 2010*

**Math**

I'm after understanding more than an answer but an answer would be greatly appreciated. The question reads as "On the answer sheet for this question is shown an x-y graph of the function [y(x)=x^2cos(3x)] Add to that same picture a rough sketch of the graph of dy/dx ...
*November 17, 2010*

**Maths**

I'm after understanding more than an answer but an answer would be greatly appreciated. The question reads as "On the answer sheet for this question is shown an x-y graph of the function [y(x)=x^2cos(3x)] Add to that same picture a rough sketch of the graph of dy/dx ...
*November 16, 2010*

**math; distributive property;perimeter of a triangl**

use the distributive property to write an equivalent expression for the perimiter of the trangle?
*November 14, 2010*

**science**

need to identify the elements, compounds and mixtures of the iron and sulpher reaction.
*November 12, 2010*

**Biology**

Action potentials: Tick the box next to the ONE answer you believe is TRUE. A. compound action potentials increase in amplitude as the stimulus strength is increased. B. ONE action potential takes in the order of 1-2 seconds to be observed. C. generation decreases the Na+ ...
*November 8, 2010*

**math**

the curve y=x^2 - 3x - 4 cross the x-axis at P and Q. the tangent to the curve at P and Q meet at R. the normals to the curve at P and Q meet at S Find the distance RS?? please help i have honestly tried and have had no luck :)
*November 8, 2010*

**math**

the curve y=x^2 - 3x - 4 cross the x-axis at P and Q. the tangent to the curve at P and Q meet at R. the normals to the curve at P and Q meet at S Find the distance RS?? please help i have honestly tried and have had no luck :)
*November 8, 2010*

**english**

Please correct my english! Hello everybody! I'm not an english speaker, but currently study english at school. Our homework is to write an english dissertation. But before it, we should give the teacher the detailed plan. It's noted, so I will be very thankfull if ...
*November 8, 2010*

**us history**

what is a social contract?
*November 7, 2010*

**Science**

15/58
*November 4, 2010*

**derivative**

Anonymous is wrong, don't use that. bobpursley and I are correct.
*November 4, 2010*

**derivative**

Is that the 5th root of (3+5x+x^3)? If so, you can rewrite it as (3+5x+x^3)^(1/5). You have to use the chain rule to find this derivative. First set (3+5x+x^3)=z. You know have z^(1/5). Take the derivative of this. (1/5)z^(1/5-1)=(1/5)z^(-4/5). Now substitute (3+5x+x^3) back ...
*November 4, 2010*

**chemistry**

One way that safety enters into specifications is to specify the composition of a vapor in air that could burn if ignited. If the range of concentration of benzene in air in which ignition could take place is 1.4 to 8.0 percent, what would be the corresponding temperatures for...
*November 4, 2010*

**physics**

What gravitational force do the two protons in the helium nucleus exert on each other? Their separation is approximately 1.0 {\rm fm}.
*November 4, 2010*

**marketing research**

is a random sample of 500 students large enough to represent all of the full time college students in the united states?
*November 4, 2010*

**grammar**

I'm trying to figure out how this sentence should be correctly punctuated. He soon found out that it was just what it was called, a dream. Specifically, I'm questioning the comma after called.
*November 3, 2010*

**PHYSICS**

Two satellites A and B are in different circular orbits about the earth. The orbit speed of satellite A is three times that of satellite B. Find the ratio (TA/TB) of the periods of the satellite.
*November 1, 2010*

**phsyics**

Each of the space shuttle’s main engines is fed liquid hydrogen by a high-pressure pump. Turbine blades inside the pump rotate at 617 rev/s. A point on one of the blades traces out a circle with a radius of 0.020 m as the blade rotates. (a) What is the magnitude of the ...
*November 1, 2010*

**calculus**

Find the relative extrema of f(x) = -2x^2 + 4x + 3 I don't know how to use the First derivative test to find it.
*October 31, 2010*

**chem**

a molar elipticity [q]466 nm, 25 C of D(−) − Co(en)3I3.H2O and obtained -5940 deg.cm2.decimol-1. Calculate the elipticity angleq (in mdeg) assuming they dissolved 0.25 g sample in 5 mL of H2O and used a 1 x 1 cm cuvette. (
*October 31, 2010*

**physics**

in a tug of war a jeep of a mass 1400kg and a tractor of a mass of 2000kg pull on a horizontal rope in opposite directions. at one instant, the tractor pulls on the rope with a force of 1.50*10^4N while its wheels push horizontally against the groud with a force of 1.60*10^4N ...
*October 30, 2010*

**Organic Chemistry**

In the substitution reaction of 2-pentanol with sulfuric acid and sodium bromide, how many grams of sodium bromide and mL of sulfuric acid would be required if we use 3.5 grams of 2-pentanol?
*October 27, 2010*

**Chemistry**

the activation energy for the decomposition of HI(g) to H2(g) and I2(g) is 186kj/mol. the rate constant at 555k is 3.42 x 10^-7 L/mol*s. What is the rate constant at 645K? Please Show all Steps! thank you!
*October 26, 2010*

**Maths**

Find all the roots of the equation Sin(2x)=1/2 in the range of -pi<x<pi giving answers in radians as multiples of Pi
*October 22, 2010*

**Science**

Help!! How many atoms in 3.45 mL of water? (H2O only;mL=g) and If you are out panning for gold and discover a nugget that is exactly 2.50 moles, how many molecules, atoms, and grams would you have? At a cost of $375 per ounce, what would be the value of gold?
*October 20, 2010*

**stat**

Microbes in a certain colony exposed to radiation have a 1=6 chance of being mutated. a. If ten microbes from the colony are sampled, what is the probability that exactly 4 will be mutated? b. If ten microbes from the colony are sampled, what is the probability that at most 4 ...
*October 20, 2010*

**Chemistry**

50 mL of Water Ti = 20C Tf = 45C d = 1.00 g/mL C = 4.184 J/g * C 50 mL * 1.00g/mL = 50 g Delta T = 45-20 = 25 C q = m * C * T = (50) (4.184) (25) = - 5230 J -5230/-82800 = 0.061 mol Molar mass of CaCl2 = 110.98 g/mol 0.061 mol * 110.98 g/mol = 6.77 g
*October 19, 2010*

**7th grade**

What is the rule for this function? Input 1, 2, 4, 5, 10, 12 output 3, 5, 9, 11, 21, 25
*October 18, 2010*

**Calculus **

A particle is moving along the curve y = 2 √{3 x + 7}. As the particle passes through the point (3, 8), its x-coordinate increases at a rate of 5 units per second. Find the rate of change of the distance from the particle to the origin at this instant.
*October 18, 2010*

**Calculus **

A particle is moving along the curve y = 2 √{3 x + 7}. As the particle passes through the point (3, 8), its x-coordinate increases at a rate of 5 units per second. Find the rate of change of the distance from the particle to the origin at this instant.
*October 18, 2010*

**science**

a microscope has two types of these
*October 17, 2010*

**science**

a microscope has two of these
*October 17, 2010*

**math**

how do you show that line 3x+y-2=0 is a tangent of the curve y=(4x-3)(x-2) and how to find the point of contact??
*October 17, 2010*

**stats**

yes.. good job
*October 16, 2010*

**mathmath**

A study conducted by the Metro Housing Agency in a midwestern city revealed the information below concerning the age distribution of renters in the city. (Round your answers to four decimal places.) Age Adult Population, % Group Who Are Renters, % 21-44 53 64 45-64 29 43 65 ...
*October 15, 2010*

**Algebra**

Determine the number of terms in the expression 14m - 16.
*October 14, 2010*

**5th grade English**

She will become a physicist one day. Have to identify the verb or verb phrase and then tell if it contains a linking verb or does not. will become=verb phrase contains linking verb
*October 14, 2010*

**calculus**

Find the 1st derivative of the function: y = 1/4 sin^2 (2x) So confused...
*October 13, 2010*

**Math**

what is the prime factorization of 72
*October 13, 2010*

**math**

A(-1,-2) B(7,2) show that the lenght AB may be written in the form p root5 wjere p is an integer to be found?? is then ans just 4root5?? if not hep please thenks
*October 13, 2010*

**Math**

make up a data set of at least 12 numbers that have the following landmarks. maximum 18 mode 7 range 13 median 12
*October 12, 2010*

**physics college**

Water flows (velocity initial=0) over a dam at the rate of 660 kg/s and falls vertically 81 m before striking the turbine blades. Calculate the rate at which mechanical energy is transfered to the turbine blades, assuming 55% efficiency.
*October 8, 2010*

**Physics**

Water flows (velocity initial=0) over a dam at the rate of 660 kg/s and falls vertically 81 m before striking the turbine blades. Calculate the rate at which mechanical energy is transfered to the turbine blades, assuming 55% efficiency.
*October 8, 2010*

**chemistry**

the molar mass of a newly synthesized jluorocarbon was measured in a gas microbalance, This device consists of a gkass bulb forming one end of a beam, the whole surrouned by a closed container. The beam is pivoted and the balance point is attained by raising the pressure of ...
*October 6, 2010*

**Science**

How are the structures in genetics related?
*October 5, 2010*

**Science **

How do you represent data in a graph?
*October 5, 2010*

**chemistry**

A sample of an ideal gas at 15.0 atm and 10.0 L is allowed to expand against a constant external pressure of 2.00 atm at a constant temperature. Calculate the work in units of kJ for the gas expansion. (Hint: Boyle's law applies) Please explain thoroughly! thank you!
*October 4, 2010*

**math**

How do i show work for this math question. A puppet requires 3/4 yard of material. How many puppets can be made from 9 yards of material?
*October 4, 2010*

**Chemistry**

H2O (l) requires the largest amount of energy to raise the temperature of 25.0g H2O of the substance from 15.0 *C to 37.0 *C. Calculate the energy. Hg (l) has the largest temperature change when 550 g of the substance absorbs 10.7kJ of energy. Calculate the temperature change...
*October 3, 2010*

**Chemistry**

A sample of an ideal gas at 15.0 atm and 10.0 L is allowed to expand against a constant external pressure of 2.00 atm at a constant temperature. Calculate the work in units of kJ for the gas expansion. (Hint: Boyle's law applies) Please explain thoroughly! thank you!
*October 3, 2010*

**physics**

A picture hangs on the wall suspended by two strings, with è = 61°. The tension in string 1 is 1.8 N. è is connected to string 1, and 32° is connected to string 2. (a) Is the tension in string 1 greater than, less than, or equal to the tension in string 2...
*September 30, 2010*

**physics**

please help! physics doesn't click with me. thank you for your help! A 23 kg suitcase is being pulled with a constant speed by a handle that is at an angle of 25° above the horizontal. If the normal force exerted on the suitcase is 155 N, what is the force F applied to...
*September 30, 2010*

**Chemistry**

For every liter of sea water that evaporates, 3.70g of magnesium hydroxide are produced. How many liters of sea water must evaporate to produce 5.00 moles of magnesium hydroxide? Please show and explain all steps! Thank you!
*September 29, 2010*

**math**

Marcus want to make a stone walkway in his garden.the rectangular walkway will be 3 feet wide and 18 feet long.Each 2-foot by 3-foot stone covers an area of 6 sq. feet.How many stones will he need? is it 9?
*September 27, 2010*

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