Friday

July 31, 2015

July 31, 2015

Total # Posts: 777

**physics **

A typical multivitamin tablet can contain 2.00mg of vitamin B2 (riboflavin), and the RDA is 0.0030 g/day. How many such tablets should a person take each day to get the proper amount of this vitamin, assuming that he gets none from any other sources?
*January 28, 2015*

**chemistry 116**

The thermite reaction demonstrated in class requires high temperatures to start the reaction. A simple open flame is not enough to start the reaction. Once the reaction is going, then it generates enough heat to keep the reaction going. According to the literature on thermite...
*January 28, 2015*

**chemistry 116**

A 36.0 g piece of copper at 130.0 C is placed in 50.0 g of water at 20.0 C. What is the temperature (in C) of the water once the system reaches equilibrium? The molar heat capacity of copper is 24.5 J/(mol·K). The specific heat capacity of water is 4.18 J/(g·K...
*January 27, 2015*

**chem**

so i did 17000 x4.18x(86-46)=284 is that what you meant
*January 27, 2015*

**chem**

The radiator in your car uses either water or ethylene glycol (anti-freeze) to remove heat from the engine and dissipate it to the outside air. If the water recirculation rate is 17.0 kg per minute of water and the water temperature leaving the engine and entering the ...
*January 27, 2015*

**chem**

thank you i got 801.1678 is that correct
*January 27, 2015*

**chem**

If you burn 13.7 g of methane (CH4) burns in oxygen, then 686 kJ is evolved. What is the amount of heat produced per mole of methane burned?
*January 27, 2015*

**chem**

Suppose you mix hydrogen, CCl4, CO2, NO2 and fluorine gases together and allow them to reach an equilibrium temperature. Which gas has the SLOWEST average molecular (or atomic) speed?
*January 26, 2015*

**History**

Really far north it would be september?
*January 21, 2015*

**History**

What time of year does snow come to the far north?
*January 21, 2015*

**Math**

I'm less than a hundred, the sum of my digits 17, I am a even number
*January 15, 2015*

**chemistry Drbobz222**

How do i convert mols CaCl2 to AgCl
*January 12, 2015*

**biology**

What role does the lilac flower play in its natural ecosystem? What is its niche in the food web Are there any ecological issues surrounding the lilac flower(e.g. are its populations decreasing, is it spreading uncontrollably..)
*December 23, 2014*

**Physics**

is there a site that can also help me
*December 20, 2014*

**Physics**

my question is: What is the purpose of the resonator of a stringed instrument
*December 20, 2014*

**Physics**

What is the purpose of the resonator stringed instrument
*December 20, 2014*

**History**

July 4, 1776
*December 16, 2014*

**chemistry**

What is the final concentration of 35.7mL of 52.0% m/m solution that is diluted to 65.9ml? i am not sure how to caluclate this... but i know the formula is C1V1=C2V2
*December 16, 2014*

**chemistry**

What is the mass of 4.3 × 10 to the power of15 atoms of nickel (Ni)?
*December 7, 2014*

**Chemistry**

I don't understand.. under Sam
*November 21, 2014*

**Chemistry **

A sample of toluene, C7H8 has a mass of 74.5 g. How many moles of benzene does it contain? How many molecules does the sample contain? How many carbon atoms does it contain?
*November 21, 2014*

**physics**

The block of mass 1.43443 kg has an acceleration of 3.6 m/s^2 as shown. What is the magnitude of F? Assume the acceleration due to gravity is 9.8 m/s^2 and the surface is frictionles
*November 13, 2014*

**science **

A 5.0 kg model vehicle travelling at 14 m/s experiences a rocket boost of 85 N ( in the direction of motion) for 20 s What is the resulting speed? The answer is 350 but i dont know how to get to that answer
*November 6, 2014*

**Math**

I dont get this eather i really would like to know how people get the answer
*November 5, 2014*

**chemistry**

Complete and balance the following reactions, where applicable. If no reaction occurs, write N.R. Li + H2O ---> KCI + F2 ---> Au + HNO3 ----> CI2 + NaF ---> Li + Fe(NO3)3 --->
*November 3, 2014*

**chemistry**

Why is it important to make sure that the volume of water and the starting temperature are the same in each trial ?
*October 28, 2014*

**physics**

A boy runs 18.4 blocks North, 12.9 blocks Northeast, and 19.7 blocks West. a)Determine the length of the displacement vector that goes from the starting point to his final position. b)Determine the direction of the displacement vector. Use counterclockwise as the positive ...
*October 16, 2014*

**physics asap!!! thank you**

A boy runs 18.4 blocks North, 12.9 blocks Northeast, and 19.7 blocks West. a)Determine the length of the displacement vector that goes from the starting point to his final position. b)Determine the direction of the displacement vector. Use counterclockwise as the positive ...
*October 16, 2014*

**physics **

The pilot of an aircraft wishes to fly due west in a 50.0 km/h wind blowing toward the south. The speed of the aircraft in the absence of a wind is 228 km/h. a) How many degrees from west should the aircraft head? Let clockwise be positive. Answer in units of degrees. b) What ...
*October 15, 2014*

**Math**

Figure it out its hw so stop searching it up
*October 7, 2014*

**Chemistry**

A sprinter must average 24.0 mi/h to win a 100-m dash in 9.30 s. What is his wavelength at this speed if his mass is 84.5 kg?
*October 5, 2014*

**physics**

Cameron kicks a football with an initial vertical velocity of 18.5 m/s and an initial horizontal velocity of 18 m/s and there is a flight time of approximately 2.0 s. Will the field goal travel far enough to make the field goal from 29 m away (if the ball is high enough to ...
*September 12, 2014*

**Physics**

How long is Mayra, a ballerina, in the air when she leaps straight up with a speed of 1.23 m/s?
*September 11, 2014*

**Algebra 2**

Has to be 2.
*May 19, 2014*

**Algebra 2**

or 3 i think?
*May 19, 2014*

**Algebra 2**

Amanda surveyed 20 juniors and seniors at Delamar high school to find the number of hours per week they spend working at part-time jobs. Her results are shown below. Juniors: 20,10,20,10,15,0,0,10,20,15 Seniors: 20,20,10,10,0,0,0,10,0,10 which statement about the data is true...
*May 19, 2014*

**Chemistry**

If 689000 J of energy are added to 4.00 L of water at 284 K, what will the ﬁnal temperature of the water be? Answer in units of K
*March 19, 2014*

**Chemistry**

Determine the speciﬁc heat of a material if a 34.7 g sample absorbed 45.2 J as it was heated from 293 K to 318 K. Answer in units of J/g · K Your answer must be within ± 2.0%
*March 19, 2014*

**chemistry**

Calculate the H3O+ concentration present in water under the following conditions. Enter your answer in scientific notation. a. [OH-] = 2.8 x 10-7 M b. [OH-] = 8.8 x 10-3 M c. [OH-] = 2.4 x 10-11 M everytime I do the problem In the calculator I get system error someone please ...
*March 19, 2014*

**Chemistry**

Calculate the pH of a solution in which a. [H3O+] = 7.8 x 10-7 M pH = b. [H3O+] = 5.1 x 10-6 M pH = c. [H3O+] = 6.1 x 10-5 M pH = d. [H3O+] = 9.3 x 10-4 M pH = I get 8.1 9.5 9.1 6.7 but its wrong please someone help!
*March 19, 2014*

**Chem**

Give the formula for the conjugate base of each acid. A.HSO4- B.H3PO4 C.HPO42- I have my answers as h2so4 h2po4 h2po4- my answrers are wrong, please help
*March 18, 2014*

**science HELP ASAP!!!!!!!**

Please, I need help with the same questions!
*March 3, 2014*

**HELP! HELP! HELP! Physics**

The surface density of a thin rectangle varies as: σ(x,y)= 14.0 kg/m2 + 9.00 kg/m4(x2+y2) The rectangle has a length L = 0.500 m and a width W = 1.500 m. Calculate Iz, the moment of inertia about the z-axis.
*February 12, 2014*

**Help - physics**

A block of mass 0.74 kg is suspended by a string which is wrapped so that it is at a radius of 0.060 m from the center of a pulley. The moment of inertia of the pulley is 0.0061 kg·m2. There is friction as the pulley turns. The block starts from rest, and its speed ...
*February 12, 2014*

**Physics Help..**

The surface density of a thin rectangle varies as: σ(x,y)= 14.0 kg/m2 + 9.00 kg/m4(x2+y2) The rectangle has a length L = 0.500 m and a width W = 1.500 m. Calculate Iz, the moment of inertia about the z-axis.
*February 12, 2014*

**physics**

A block of mass 0.74 kg is suspended by a string which is wrapped so that it is at a radius of 0.060 m from the center of a pulley. The moment of inertia of the pulley is 0.0061 kg·m2. There is friction as the pulley turns. The block starts from rest, and its speed ...
*February 12, 2014*

**Algebra 1**

I think I figured out a few of them the fist is given second is distributive third is Commutative and I am not sure about the rest
*January 18, 2014*

**Algebra 1 **

Give the reason (property) for each step in the simplification. 8(a+b)-3a (8a+8b)-3a (8b+8a)-3a 8b+(8a-3a) 8b+5a
*January 18, 2014*

**Physics **

A train traveling at a speed of 110 km/h uniformly decelerates for 20 seconds. During that time it travels 450m. A) What is the acceleration? (m/s^2) B) What is its speed after deceleration? (km/h) A ANS = -.805m/s^2 B ANS = 52km s = 450m t = 20 seconds u = 110km/h*1000m/km /...
*January 11, 2014*

**Kensignton Park**

I have to find two numbers the quotient is between. 393
*January 8, 2014*

**Physics**

A train traveling at a speed of 110km/h uniformly decelerates for 20 seconds. During that time it travels 450m a) what is the acceleration m/s square? b) what is its speed after the deceleration? (km/h) Could really use some help. Thank you.
*January 1, 2014*

**Math**

100 cm = 1 meter Is 172.500 kN correct?
*December 26, 2013*

**Math**

The air pressure in a tire is 150.000 kPa. The internal surface area of the tire is 1150.000 cm^2. Determine the total force applied by the air to the tire. (Round to 3 decimal places) Answer = kN 150.000 kPa x 1000 = 150000 Nm 1150.000 cm / 100 cm = 11.5 m Force = Pressure x ...
*December 26, 2013*

**Math**

The air pressure in a tire is 800.000kPa.The internal surface area of the tire is 550.000cm^2. Determine the total force applied by the air to the tire. (Round to 3 decimal places). ANS = 44.000kN Force = Pressure x Area = 800.000kPa x 550.000 = 440000.000N = 440.000kN I keep ...
*December 26, 2013*

**Math**

Thank you very much.
*December 21, 2013*

**Math**

Where do you get the 1.18 from. Confused a little.
*December 21, 2013*

**Math**

A spring is 25 cm long when stretched. The spring was stretched by 18% of its original length. Determine the original length.
*December 21, 2013*

**calculus**

Imagine making a tent in the shape of a right prism whose cross-section is an equilateral triangle (the door is on one of the triangular ends). Assume we want the volume to be 2.2 m3, to sleep two or three people. The floor of the tent is cheaper material than the rest: assume...
*December 10, 2013*

**physics**

a uniform (in density and shape) stick is balanced by one end on the ground and the other tied to a massless horizontal rope attached to a wall as shown in the figure. The stick's mass is 10kg and its length is 5m. a. Calculate the tension on the rope b. Calculate the ...
*November 21, 2013*

**grammar**

Which part of speech is the capitalized words in this sentence? Four score and seven years ago our fathers brought forth on this continent, a NEW nation, conceived in Liberty, and DEDICATED to the proposition that all men are created equal. Now we are engaged in a great civil ...
*November 17, 2013*

**physics1111**

Rubbing your hands together warms them by converting work into thermal energy. If a woman rubs her hands back and forth for a total of 14 rubs a distance of 7.50 cm each and with a frictional force averaging 30.0 N, what is the temperature increase? The mass of tissue warmed ...
*November 12, 2013*

**Math**

If p^2-q^2=12, and p+q=4 What is the value of p?
*November 2, 2013*

**PHSYICS!**

I solved it and I'm pretty sure it comes around 5.7168.
*October 31, 2013*

**Confused**

Wait, does that mean f to the x power or f * x? An you know your supposed to find what F and G are, right?
*October 31, 2013*

**books Hamlet**

I need to identity three siutaions that Hamlet, Laertes and Fortinbras all share. I have one situation that they all share which is where all of their fathers are dead. I need two more, but I don't see any in the book. if anyone knows any helpful sites or two situations, ...
*October 30, 2013*

**Punctuation Sentence**

Thanks
*October 23, 2013*

**Punctuation Sentence**

Select the correct sentence. 1. Dr. Jones is an excellent surgeon but does not have a good bedside manner. 2. Dr. Jones is an excellent surgeon, but does not have a good bedside manner. 3. Dr. Jones, is an excellent surgeon, but does not have a good bedside manner. Is #2 ...
*October 23, 2013*

**Algebra1**

12"21
*October 3, 2013*

**Algebra1**

12"20
*October 3, 2013*

**Algebra1**

8:12
*October 3, 2013*

**Algebra1**

8/20
*October 3, 2013*

**spanish**

Nosotros siempre _____ la comida. A. comparten B. comparto C. compartimos D. comparte A?
*September 16, 2013*

**Spanish**

_____ las salchichas. Como salchichas todos los días. A. Me gusta mucho B. Me encantan C. No me gustan nada D. Me encanta B?
*September 16, 2013*

**Spanish**

Thank you. :)
*September 16, 2013*

**Spanish**

¿Con quién _____ tú el almuerzo? A. comparto B. compartes C. compartimos D. comparte B?
*September 16, 2013*

**4th grade math**

Thank you
*September 10, 2013*

**4th grade math**

I have to make a table or list to solve these problems. 1. Tina and Bruce are each rolling a 1 to 6 number cube. They are looking for different ways to roll two factors whose product is greater than 14. How many different ways will they find? 2. Trenton has 2 hats and 6 ...
*September 10, 2013*

**Spanish 1**

No Jake, it's C.
*September 10, 2013*

**Physical Science**

Radio waves and then also it could be infrared or microwave cause they are longer than any other type of waves. Radio is used in radio transmission - by taking large wavelengths and conducting them by using antennas to cover large distances. Microwaves are used in all wireless...
*September 5, 2013*

**Physical Science **

The Magnetic field lines of a bar magnet begin near the magnet's _____________. I believe this question is asking where the lines begin (ie leave) the bar magnet...which would be the north pole.
*September 4, 2013*

**Physical Science**

Yes, I found it. :) thanks.
*September 4, 2013*

**Physical Science**

It's A.
*September 4, 2013*

**Physical Science **

The primary colors of pigments A. are cyan, yellow, and magenta. B. are the same as the secondary colors of light. C. combine in equal amounts to produce black. D. all of the above I think it's D.
*September 4, 2013*

**Physical Science **

Energy from the sun reaches Earth mostly by A. conduction. B. convection. C. radiation. D. thermal expansion. I think it's A.
*September 3, 2013*

**Physical Science **

If no friction acts on a diver during a dive, then which of the following statements is true? A. The total mechanical energy of the system increases. B. Potential energy can be converted into kinetic energy but not vice versa. C. (KE+ PE)beginning = (KE + PE)end D. all of the ...
*September 3, 2013*

**Physical Science **

When opposite poles of two magnets are brought together, the poles A. attract each other. B. repel each other. C. cancel each other. D. cause a net force of zero. I think it's B.
*September 3, 2013*

**Physical Science**

Which of the following is a heterogeneous mixture? A. water in a swimming pool B. sugar water C. a jar of mixed nuts D. stainless steel I think it's B.
*August 27, 2013*

**Physics**

A tie bar is made of a material having a tensile strength of 231 MPa and has to carry a load of 255 kN. What is the diameter of the bar if a factor of safety of 7 is applied? ANS = 99.2 mm Cannot figure out how to get the answer. Need help please. Thank you
*August 17, 2013*

**Stress & Strain (Help Please)**

A tie bar is made of a material having a tensile strength of 231 MPa and has to carry a load of 255 kN. What id the diameter of the bar if a factor of safety of 7 is applied? ANS = 99.2 mm Cannot figure out how to get the answer. Need help please. Thank you
*August 10, 2013*

**Physics**

A boiler furnace releases 10000.000kJ of heat for each kg of fuel burned and produces dry saturated steam at 10000.000kPa from feed water at 190.000 degrees Celsius. How many kg of steam will be produced for each kg of fuel burned if the boiler had an efficiency of 69%? ANS = ...
*July 31, 2013*

**Thermodynamics of steam**

A boiler furnace releases 10000.000kJ of heat for each kg of fuel burned and produces dry saturated steam at 10000.000kPa from feed water at 190.000 degrees Celsius. How many kg of steam will be produced for each kg of fuel burned if the boiler had an efficiency of 69%. ANS = ...
*July 22, 2013*

**Physics**

When working with the properties of Saturated Steam. The pressure table supplied states: Pressure kPa = 1100 (P) Temp in Celsius = 184.09 (T) Specific Volume = Sat. Liquid = 1.1330 (Vf) Specific Volume = Sat.Vapor = 177.53 (Vg) Enthalpy = Saturated Liquid = 781.34 (Hf) ...
*July 21, 2013*

**Math (please help steve)**

Brilli the ant randomly placed a token into a square on a 2×100 chessboard according to a probability distribution P. The token is then moved uniformly at random to one of the horizontally, vertically, or diagonally adjacent squares. The probability that the token is in ...
*July 16, 2013*

**Math (please help steve)**

Brilli the ant is considering the complexities of a 5-dimensional universe. She wants to count the number of integer points that are distance n√ away from the origin. Let Tn be the set of ordered 5-tuples of integers (a1,a2,a3,a4,a5) such that a1^2+a2^2+a3^2+a4^2+a5^2=n....
*July 16, 2013*

**Math (help steve)**

Brilli the ant placed the numbers 1,2,…,n in order clockwise around a circle. She can create an infinite sequence A={aj}∞j=0 of integers by letting a0=k∈{1,2,…,n} and constructing ai+1 from ai by taking the integer that is ai positions clockwise in the ...
*July 16, 2013*

**Math (algebra)**

What are the last three digits of the largest perfect square that can be expressed as p^2+pq+q^2, where p and q are (positive) prime numbers?
*July 16, 2013*

**Math (algebra)**

Let x,y be complex numbers satisfying x+y=a xy=b, where a and b are positive integers from 1 to 100 inclusive. What is the sum of all possible distinct values of a such that x^3+y^3 is a positive prime number?
*July 16, 2013*