# Posts by Jack

Total # Posts: 1,821

**physical chemistry**

1 kg aluminum dumbbell initially held 2 meters above the floor is allowed to fall. This experiment is performed inside a room whose dimensions are 10m × 5m × 3m. Assuming that the walls of the room do not conduct heat and that the room is empty (no other objects ...

**Chemistry**

How do I balance this equation and what is the answer? C3H9N+O2-->CO2+H2O+NO2

**Chemistry**

How much ice is required to cool a 15.0 oz drink from 71 F to 34F, if the heat capacity of the drink is 4.18 J/g*C? (Assume that the heat transfer is 100 % efficient.)

**english**

What is 7 letter word for finished. 3rd letter is R and 5th letter is U

**Geography**

a lot of reason :)

**physics**

Modern lasers can create a pulse of light that lasts only a few femtoseconds. (a) What is the length of a pulse of red light that lasts 6.2 fs? (b) How many wavelengths of red light (ë = 680 nm) are included in such a pulse?

**physics**

Modern lasers can create a pulse of light that lasts only a few femtoseconds. (a) What is the length of a pulse of red light that lasts 6.2 fs? (b) How many wavelengths of red light (ë = 680 nm) are included in such a pulse?

**operating system**

in windows vista, how do you organize file list by file size?

**chemistry**

V=359L

**chemistry**

What volume does a mixture of 14.2g of helium and 21.6g of hydrogen gas occupy at 28 degrees celcius and .985atm?

**5th grade math**

my bad it is 2/5 not 3/5

**5th grade math**

3/5 change the denominator to 15 by multiplying by 3 so it is 9/15-3/15=6/15 if you reduce it is 3/5

**Spanish**

22. C 23 a

**Math help once again**

10^y=x so 10^10=x

**chemistry**

thanks i solved it already

**chemistry**

Ammonia reacts with oxygen gas to form nitrogen monoxide and water. At constant temperture and pressure, how many of nitrogen monoxide can be made by the reaction of 800. ml of oxygen gas?

**Spanish**

it is asking if you have to have your lobster cooked with butter

**Math**

If line f is parallel to the line h, and line f has y-intercept 5, what is the equation of line f ? With h passing through two points (1, 2) and (3, 6)

**CHM**

Assuming the density of acetic acid solution is 1.0 g/mL, determine the volume of the acetic acid solution necessary to neutralize 25.0 mL of 0.10 M NaOH. Record this calculation on your report sheet

**Math**

If line g passes through point (2, 2) and is perpendicular to the line h, then what is the equation of line g? With h passing through two points (1, 2) and (3, 6)

**Math**

If line f is parallel to the line h, and line f has y-intercept 5, what is the equation of line f ? With h passing through two points (1, 2) and (3, 6)

**Math**

If line f is parallel to the line h, and line f has y-intercept 5, what is the equation of line f ? With h passing h through two points (1, 2) and (3, 6)

**algebra**

a rectangular sheet of plywood is seven times longer than its width,write an simlify an expression for the perimeter of the rectangle in terms of the width.

**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 ...

**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 ...

**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?

**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 ...

**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!

**algebra**

iove

**algebra**

8q2 – 3q – 2 = 0

**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.

**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?

**grammar**

Ok thanks, so there are only two avderbs in this entire paragraph?

**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...

**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

**Math**

Solve the proportion for u. (u-2):(u+3) = 4:3

**math**

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

**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 ...

**math**

Can the expression (r-3)(s+2) be simplified without knowing the values of r and s?

**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?

**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 ...

**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.

**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 = ...

**Chemistry**

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

**Chemistry**

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

**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 ...

**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

**accounting**

Does the flexible budget term mean A series of budgets for varying rates of activity?

**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?

**10th grade**

How many grams of cacl2 are in 4.3l solution of 2.8 m cacl2

**physics**

thank you so much!!!

**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 that's where i get lost

**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 ...

**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 ...

**physics**

Wouldn't it be zero. It's speed at the top and bottom are zero so...

**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?

**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?

**chemistry**

thanks! that helped me solve the problems.

**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?

**chemistry**

sorry, answer found. no longer need help..

**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.

**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.

**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.

**chemistry**

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

**Math**

A ramp of length 6, width 4, and height 2.

**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)

**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?

**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)

**Math**

60 miles. 4mph * 15 hours = 60 miles 20mph * 3 Hours = 60 miles

**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

**calculus**

2 - 6X

**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.

**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 ...

**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 ...

**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 ...

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

use the distributive property to write an equivalent expression for the perimiter of the trangle?

**science**

need to identify the elements, compounds and mixtures of the iron and sulpher reaction.

**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+ ...

**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 :)

**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 :)

**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 ...

**us history**

what is a social contract?

**Science**

15/58

**derivative**

Anonymous is wrong, don't use that. bobpursley and I are correct.

**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 ...

**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...

**physics**

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

**marketing research**

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

**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.

**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.

**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 ...

**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.

**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. (

**Chemistry**

210

**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 ...

**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?

**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!

**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

**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?

**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 ...