# Posts by Jack

Total # Posts: 1,753

**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*

**calculus**

Verify that the Intermediate Value theorem applies to the indicated interval and find the value of c guaranteed by the theorem. f(x) = x^2 - 6x + 8, [0,3], f(c) = 0 I have no idea how to use the theorem :(

*September 27, 2010*

**science**

What is the chemical name for Polyurethane and what does it look like at it's resting state?

*September 26, 2010*

**Avon k 8 Center**

If 50 is the first number, what is the second number?

*September 24, 2010*

**6th grade**

Next, Tom remembers that he heard a doctor talking about something that takes two weeks to heal. I have to identify what type of pronoun that (second one in sentence) is. Would it be a relative pronoun?

*September 22, 2010*

**Chemistry**

ammonia gas reacts with copper (ii) oxide at high temperatures to produce elemental nitrogen, copper metal, and water vapor. Assume that 36.2g ammonia reacts with 180.8 g copper ii oxide. (balanced equation: 2 NH4 (ammonium) (g) + 4 CuO (copper ii oxide) ==> N2 (nitrogen ...

*September 21, 2010*

**Chemistry**

Find the limiting reagent. 2 NH4 (g) + 4 CuO (s) ==> N2(g) + 4 Cu(s) + 4H2O (g) Please explain, thank you!

*September 21, 2010*

**Chemistry**

Find the limiting reagent. 2 NH4 (g) + 4 CuO (s) ==> N2(g) + 4 Cu(s) + 4H2O (g) Please explain, thank you!

*September 21, 2010*

**Chemistry**

61.0 mL of a 1.50 M solution is diluted to a volume of 258 mL. A 129-mL portion of that solution is diluted using 167 mL of water. What is the final concentration?

*September 19, 2010*

**calculus**

Fond the limit of lim x -> 3 [1/(x+4)] - (1/4) _________________ x

*September 19, 2010*

**Chemistry**

DDT, an insecticide harmful to fish, birds, and humans, is produced by the following reaction: 2 C 6 H 5 Cl (Chlorobenzene) + C 2 H O Cl 3(chloral) ==> C 14 H 9 Cl 5 (DDT) + H 2 O In a government lab, 1142 g of chlorobenzene is reacted with 485g of Chloral. A)What mass of ...

*September 19, 2010*

**physics**

A hot air balloon has just lifted off and is rising at the constant rate of 1.8 m/s. Suddenly, one of the passengers realizes she has left her camera on the ground. A friend picks it up and tosses it straight upward with an initial speed of 11.2 m/s. If the passenger is 2.5 m ...

*September 16, 2010*

**physics**

An astronaut on Neptune drops a rock straight downward from a height of 0.95 m. If the acceleration of gravity on Neptune is 11.2 m/s2, what is the speed of the rock just before it lands? (m/s)

*September 16, 2010*

**Math**

State the Domain and show work. y = x + 2 / x^2 - 4x - 12

*September 16, 2010*

**MATH**

26=6(5-6A)

*September 16, 2010*

**calculus**

Find all possible radii of circle centered at (3,6) so that the circle intersects only one axis

*September 13, 2010*

**calculus**

Solve: sec(x)^2= 3tanx +1 *** It is suppose to be the sqaure root of 3 but i could find the symbol so just wrote the 3 without it but it is suppose to be the square root of 3 times tanx + 1

*September 13, 2010*

**math**

256 + 1,273

*September 13, 2010*

**PRE CALCULUS**

the question is actually square root of ( x+5) = x please ANSWER

*September 12, 2010*

**PRE CALCULUS**

How many real solutions does the equation ãx+5=x have? Please explain your answer to the best of your abilities thanks :)

*September 12, 2010*

**Pre CALCULUS**

How many real solutions does the equation x+5=x have? Please explain your answer to the best of your abilities thanks :)

*September 11, 2010*

**Pre Calculus**

As x increases from p/4 to 3p/2, the value of sin(x) : A.increases throughout the interval B.decreases at first, then increases C.increases at first, then decreases D.decreases throughout the interval E.none of the above please explain why the answer is as it is, I don't ...

*September 11, 2010*

**Calculus**

Solve for x: lnx^3 - 2lnx = 1 Please try and show how you got the answer best as you can thank you :)

*September 11, 2010*

**Calculus**

Solve : sec^2(x)= ã3*tanx + 1 on [0,radian-180 degrees) - couldn't find the symbol for radian on computer please try and explain how you got your answer best as yu can thanks so much :)

*September 11, 2010*

**Calculus**

The normal body temperature in humans ranges from 97.6 degrees fahrenheit to 99.6 degrees fahrenheit. Concert this temperature range into degrees celcius

*September 11, 2010*

**Calculus**

The celcius scale is devised so that 0 degrees celcius is the freezing point of water ( at 1 atmosphere of pressure) and 100 degrees celcius is the boiling point of water ( at 1 atmosphere of pressure) . If you are more familiar with the Fahrenheit scale, then you know that ...

*September 11, 2010*

**Chemistry**

A single 4p orbital can hold how many electrons? i got 6 is that correct or no? Would conducting electricity be considered a physical or a chemical property of ZINC?

*September 10, 2010*

**rounding**

(a) 455 cal to joules thats 1 903.72 joules but i need to round it to 3 sig figs how do u do that?

*September 9, 2010*

**9th grade**

we know that sum means adding. So which one of your choices deals with adding?

*September 9, 2010*

**plz help me for math**

you always want to start by putting like terms together. So why don't you do that first and then its really easy from there all you have to do is follow the signs(- or +) and add or subtract

*September 9, 2010*

**chemistry**

Would Conducting electricity be considered a physical or chemical property of zinc i got physical but just want to make sure.

*September 9, 2010*

**Chem**

Would conducting electricity be considered a physical or chemical property of ZINC i got phyiscal but just want to make sure.

*September 9, 2010*

**chemistry**

A single 4p orbital can hold how many electrons? i got 6 is that correct or no?

*September 9, 2010*

**Pre Calculus**

Determine the coordinates of the point (xy) where the curves y=(12)x−5 and y=x2+2x−15 intersect in the third quadrant

*September 8, 2010*

**Pre Calculus**

The strength of a cable is proportional to the square of its diameter. If a 2-cm cable will support 800kg, how much will a 3-cm cable support?

*September 8, 2010*

**chemistry**

A flask has a mass of 78.23 g when empty and 593.63 g when filled with water. When the same flask is filled with concentrated sulfuric acid, H2SO4, its mass is 1026.57 g. What is the density of concentrated sulfuric acid? (Assume water has a density of 1.00 g/cm3 at the ...

*September 6, 2010*

**chemistry**

Which of the following properties is a chemical property of phosphorus? Answer a) it burns in air b) it is a white waxy solid c) it melts to form a viscous liquid at 44.1 oC d) Both a and c are both examples of chemical properties. e) a, b, and c are examples of chemical ...

*September 6, 2010*

**chemistry**

Convert a density of 2.74 x 103 g/L into a density with dimensions of kg/mL. please show how would this conversion be done.??

*September 6, 2010*

**physics**

A flask has a mass of 78.23 g when empty and 593.63 g when filled with water. When the same flask is filled with concentrated sulfuric acid, H2SO4, its mass is 1026.57 g. What is the density of concentrated sulfuric acid? (Assume water has a density of 1.00 g/cm3 at the ...

*September 6, 2010*

**Mayans and aztecs**

how did the aztecs acquire most new pieces of land

*September 6, 2010*