Sunday
May 1, 2016

# Posts by Jack

Total # Posts: 1,586

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

algebra
8q2 – 3q – 2 = 0
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 math 180 m / 1 day 1 day = 24 hours * 60 min / hr = 1440 minutes Substitute 1440 minutes for 1 day in the original problem and you get: 180 m / 1440 min Reduce by dividing both the numerator and denominator by 180 and you get: 1 m / 8 min Divide both the numerator and denominator ... January 5, 2011 math Everyone of you has absolutely no idea how to solve this problem and you are simply adding to the questioner's confusion. If you don't know, just shut up. January 5, 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 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 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

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

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

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