Wednesday

January 18, 2017
Total # Posts: 1,821

**Chem**

Is this on the right track?.....mass cannot be created/destroyed, although it may be rearranged in space, and changed into different types of particles. This implies that for any chemical process in a closed system, the mass of the reactants must equal the mass of the products.

*October 5, 2010*

**Chem**

Sulfur burns in the presence of oxygen to produce sulfur dioxide. Explain how the mass of sulfur dioxide produced compares to the combined mass of sulfur and oxygen.

*October 5, 2010*

**physics/ math**

Water flows (v approx. 0) over a dam at the rate of 660 kg/s and falls vertically 86 m before striking the turbine blades. Calculate the rate at which mechanical energy is transferred to the turbine blades, assuming 53% efficiency.

*October 5, 2010*

**physics**

A 120-kg crate, starting from rest, is pulled across a floor with a constant horizontal force of 400 N. For the first 17 m the floor is frictionless, and for the next 17 m the coefficient of friction is 0.34. What is the final speed of the crate?

*October 5, 2010*

**math**

explain how you could show five less than a number using an expression

*October 4, 2010*

**Chemistry 20**

If 40. kJ of energy are absorbed by 450 g of water at 16 oC, what is the final temperature of the water?

*October 4, 2010*

**Related Rates Problem**

your kind of really bad at this

*October 1, 2010*

**grammar**

what is the simple predicate in The insects bodies can turn wood into food?

*September 28, 2010*

**algebra**

the equation is f(x) = (1/sq. root of 1-x^2) 1. f(x) is never zero. 2. 0 is in the domain of f 3. All negative real numbers are in the domain of f 4. All positive real numbers are in the domain of f 5. 1 is in the domain of f 6. f(x) is never negative 7. f(x) is never positive...

*September 24, 2010*

**math**

r=13.14

*September 22, 2010*

**math**

-3.38=r-9.76

*September 22, 2010*

**science**

Water, Oil, and sediment

*September 20, 2010*

**German**

This was a worksheet and the instruction said to fill in the adjective endings, since the underlines wouldn’t show I put the spaces to be filled as parenthesis. The (-) means I think it does not need an ending and the (?) means im confused and not sure if it needs an ...

*September 19, 2010*

**Physics**

It should have read Physics as subject- I mistyped it-Please help me understand this

*September 18, 2010*

**Physcis**

An airplane flying at 120km/h due west moves into a region where the wind is blowing at 40km/h due east. If the plane's original vecotr velocity is Vplane, what is the expression for the plane's resulting velocity in terms of Vplane. a. 1/3 >Vplane b. 2/3>Vplane ...

*September 18, 2010*

**Chemistry**

A 279 lb fullback runs the 40 yd dash at a speed of 18.5 ± 0.1 mi/h.(a) What is his de broglie wavelength (in meters)?(b)what is the uncertainty of his position?

*September 17, 2010*

**Physics**

I have a problem with an atwood's machine problem. i have three tensions where T1 and T2 are on the left and T3 is on the right. Bottom left corner is block 2kg with T1 then another block 2kg with T2 on the left side. On the right side i have a block of 7kg with T3. I am ...

*September 16, 2010*

**Physics**

This is what i've done: (i) T3sin 47 = mg (ii) 37 = T3cos 47 so i said T3 = 54.2523 N 54.25(sin47)/g = m m = 3.96776 kg

*September 15, 2010*

**Physics**

In the figure below the left hand calbe has a tension T1 and makes an angle of 42 with the horizontal. the right hand calbe as a tension T3 and makes an angle of 47 with the horizontal. The horizontal cable connecting the two masses has a tension of 37 N. Determine the mass M2.

*September 15, 2010*

**Algebra**

What is the problem precisely? What is the question?

*September 15, 2010*

**Algebra**

I think the question is asking you if the function f(x) equals 8 WHEN x equals 8; true of false? since the function is f(x)= x + 8 the answer is false because 8+10=18

*September 15, 2010*

**PHYSICS**

Since average a= delta v/ delta t 340(.05)= delta v v=17 m/s Furthermore this launch velocity has the angle of 51 degrees. You then use your handy dandy trigonometric skills to find the horizontal and vertical components of the launch velocity. 17cos(51)= horizontal find the ...

*September 15, 2010*

**math**

if a^2 + b^2 = c^2 *equation for right triangles and c in your case is 32 meters and because the obj. is a squared the sides are equal to each other therefore: 2x^2 = 32^2 x = side of square AREA= x^2 therefore : x^2 = (32^2) / 2

*September 15, 2010*

**physics**

You need an initial velocity

*September 14, 2010*

**9TH GRADE MATH**

21=5-3=7-9*2=

*September 13, 2010*

**Anatomy**

If you stand with your arms down at your sides and lift them up to shoulder height is that Adduction or Flexion?

*September 9, 2010*

**science**

what is the scientific notation for 280 mm?

*September 8, 2010*

**geometry**

Rays PQ and QR are perpindicular. Point S lies on the interior of angle PQR. If m<PQS=4+7a and m<SQR = 9+4a, find m<PQS and m<SQR

*September 8, 2010*

**math**

One year, China consumed 4 times as much energy as Brazil.Define a variable and write an expression for the amount of energy China used that year.I don't get the variable part and expression. Not the same person.

*September 8, 2010*

**math**

One year, China consumed 4 times as much energy as Brazil.Define a variable and write an expression for the amount of energy China used that year.I don't get the variable part and expression. Not the same person.

*September 8, 2010*

**college**

a rock is dropped off a bridge. How fast is it moving when it hits the water 2.5s later?

*September 7, 2010*

**Mayans and aztecs**

how did the aztecs acquire most new pieces of land

*September 6, 2010*

**math**

(17-5)(6+5) Do you know what's an expression is? Can you teach me how to do it?

*August 31, 2010*

**math**

(17-5)(6+5)

*August 31, 2010*

**math**

It means 14 divide by 2

*August 31, 2010*

**math**

14/2+3(5)

*August 31, 2010*

**math**

so, what's the right problem??????????

*August 31, 2010*

**Math**

Dave has quarters, dimes and nickles in his bank. He has 3 more dimes than quarters and 6 less nickles than quarters. There are 63 total coins. How many are quarters?

*August 26, 2010*

**8th grade**

what is a root word

*August 24, 2010*

**PHYSICS LEC**

please help...i need this immediately.. rolling friction. two bicycles are set rolling with the same initial speed of 3.50m/s on a long, straight road, and the distance each travels before its speed is reduced by half is measured. One tire is inflated to a pressure of 40psi ...

*August 16, 2010*

**geometry**

The length of a rectagle is 9 centimeters more than half the width. Find the legth if the perimeter is 60 centimeters.

*August 14, 2010*

**chemistry**

What mass of solute is needed to prepare 140 mL of 0.560 M KCl? how do i work this out?

*August 14, 2010*

**PHYSICS LAB**

a gold ball is hit with an initial velocity v0 = 53m/s at an angle of 50degrees above the horizontal. a)how high the ball go? b)what is the total time the ball is in the air? c)how far will the ball travel horizontally before it hits the ground?

*August 10, 2010*

**physics**

A long, vertical, straight wire carries a current I going upwards. The wire is perpendicular to the plane of a circular metal loop and passes through the center of the loop. The loop is allowed to fall and maintains its orientation with respect to the straight wire while doing...

*July 28, 2010*

**physics**

thanks, Bob!

*July 28, 2010*

**physics**

A step-down transformer has a turns ratio of 1:10 and its primary is connected across the terminals of a standard 120 V wall socket. A 330 ohm resistor is connected across the secondary of this transformer. What power P is dissipated in the resistor?

*July 28, 2010*

**physics**

The primary coil of a transformer is connected to a standard wall socket. A resistance R is connected across the secondary coil. The resistance across the secondary coil is increased. What happens to the current in the primary coil, and what happens to the power being supplied...

*July 28, 2010*

**PHYSICS**

if by some suitable mechanism the falling body had been given an initial downward push instead of just being released, would the resulting value of (g) acceleration due to gravity have been different?why? tnx....please answer it...

*July 26, 2010*

**PHYSICS**

a)speed is the magnitude of instantaneous velocity. Is the average speed equal to the magnitude of the average velocity? Justify b)under what condition is the average equal to instantaneous velocity? c)a car travels 40 mph for 2 hrs and 60 mph for 3hrs.what is the average speed?

*July 26, 2010*

**Eth 125**

Ms. Sue. If you are uneducated enough as to refer to the concept of orientalism as people from asian countries. Please check your facts before posting answers. Orientalism clearly defined is answer C

*July 21, 2010*

**physics**

the forces on the table act on a ring but are said to be concurrent. if the cords were rigidly to the ring would the forces necessarily be concurrent?? will you please give me some explanation answers about this...thanks a lot..

*July 20, 2010*

**pHysics**

yeah...tnx drwls...you're the best...how can you answer all those questions in just one click... i hope to have that kind of knowledge too.. tnx again

*July 20, 2010*

**pHysics**

a rope 26 ft long is attached to two points A and B, 20 ft apart at the same level. A load of 250lb is carried at the middle of the rope. what force is exerted on A. please answer this immediately i need it...thanks a lot...

*July 20, 2010*

**physics**

a brick is dropped (0 initial speed) from the top of a building. the brick strikes the ground in 2.5 seconds. you may ignore air resistant so the brick is in free fall. A)how tall in meters is the building? B) what is the magnitude of the brick's velocity just before it ...

*July 18, 2010*

**college**

a ball is thrown vertically upward from the ground with the velocity of 30m/s, a)how long will it take to rise to its highest point? b)how high does the ball rise? c)how long after projection will the ball have the velocity of 10m/s upward? tnx

*July 16, 2010*

**Geometry**

An antique dealer visited three shops. She spent $25 at the first shop. At the second shop, she spent half of her remaining money. At the third shop, she spent one third of her remaining money and had $60 left. How much money did the dealer have originally?

*July 12, 2010*

**Geometry**

Larry, Lionel, and Lester painted a fence. Larry painted the first 1/3 of the fence. Lionel painted 3/5 of what rtemained. Lester painted the final 40 ft. How long is the fence?

*July 12, 2010*

**geometry**

A snail is crawling along a meter stick. At a certain point the snail stops. The snail needs to crawl three times as far as it has already crawled in order to be 4 cm from the end. How far has the snail already crawled?

*July 12, 2010*

**physics**

A person with mass 70 kg is climbing a ladder (length 6m, mass 20 kg) that leans against a smooth wall (no friction). A frictional force fs between the ladder and the floor keeps it from slipping. The angle between the ladder and the wall is 30 degrees. What is the magnitude ...

*July 7, 2010*

**physics**

Two identical loudspeakers are 2 m apart. A person stands 4.6 m from one speaker and 3.4 m from the other. What is the lowest frequency at which destructive interference will occur at this point?

*July 4, 2010*

**Physics**

36.8

*June 30, 2010*

**physics**

A 1210 N uniform beam is attached to a vertical wall at one end and is supported by a cable at the other end. A W = 1820 N crate hangs from the far end of the beam. The angle between the beam and the horizontal is 30 degrees upwards and the angle between the horizontal and ...

*June 28, 2010*

**physics**

your approach makes a lot of sense. thanks for your help!

*June 27, 2010*

**physics**

a 20 g bullet strikes a 0.7 kg block attached to a fixed horizontal spring whose spring costant is 5600 N/m and sets it into vibration with an amplitude of 25 cm. What was the speed of the bullet before impact if the two objects move together after impact?

*June 27, 2010*

**algerbra**

i cant solve this can someone help me. 19.6 + X^2/2 ={(.007852*X /.001285)^2}/2 i know the answer is 1.01 but how do i get that

*June 23, 2010*

**physics**

how fast does the level of water in a full 2m high, 10cm diameter tank reduces when a 4cm diameter hole is opened at the bottom?

*June 23, 2010*

**college physics**

how fast does the level of water in a full 2m high, 10cm diameter tank reduces when a 4cm diameter hole is opened at the bottom?

*June 22, 2010*

**college physics**

find the weight of a piece of wood with a density of .5 g/cm cubed. which when attached to a 5kg stone in water it will sink. the density of the stone is 3g/cm cubed

*June 22, 2010*

**Psychology**

Post Hypnotic suggestions are best represented by which of the following Cocercive statements commands new ideas for self improvement Criticisms

*June 16, 2010*

**Psychology**

Either nightmares, night terrors, daydreams, or archetypical dreams

*June 16, 2010*

**Psychology**

What are dreams that contain symbolic characters and appear surreal?

*June 16, 2010*

**health**

The primary goal of wellness is the ability to achieve A.freedom from disease. B.a multicultural view of health. C.the highest possible quality of life. D.greater control over lifestyle decisions.

*June 11, 2010*

**Science**

using filtration??

*June 11, 2010*

**college physics**

find the frictional force exerted on a 20kg block pulled slowly over a horizontal floor using a rope which makes a 30 degree angle over the horizontal. the pulling force is 100N??? i found the Fn to be 146 N what do i do from there?

*June 10, 2010*

**philosophy**

What are key differences between the ontological, teleological, and cosmological arguments? Identify the philosopher who you think best supports his or her argument. Explain your answer briefly.

*May 26, 2010*

**Algebra**

Multiply 9/2 x (2/1) Type an integer or simplified fraction Very confused on this, please help

*May 26, 2010*

**algebra**

how would you write 46% and some number as an algebraic expression? Type the percentage as a decimal, and use y to represent some number?

*May 26, 2010*

**Algebra**

9/2 x (2/1) Multiply type an integer or simplified fraction. I am confused

*May 26, 2010*

**Algebra**

so, m=-5/2 ?

*May 26, 2010*

**physics**

a sled is pulled at a velocity across a horizontal snow surface. if a force of 8.0x10 to the first power N is being applied to a sled rope at an angle of 53 degrees to the ground, what is the magnitude force of friction

*May 24, 2010*

**10th grade**

the circle is circumscribed by the pentagon as shown (not drawn to scale). If QZ=10, YX=9, XW=9, UW=17, and SU=10, find the perimeter of the pentagon.

*May 20, 2010*

**englsh 3**

we are doing conjuction and compound sentences in class, and i need help diagraming this sentence: Little Red Ridinghood and her mother packed her basket witk cookies for her grandma.

*May 19, 2010*

**Government**

Which of the following is not a long term trend marking the expansion of suffrage in the United States?

*May 19, 2010*

**5th grade math**

Thanks! It was hard when I wasn't thinking that way! Now, I am able to do the rest of my homework without any trouble! Thanks for explaining it!

*May 14, 2010*

**5th grade math**

I came up with the answer of 12. Common greatest factor is 12. hope I did it right!Thanks again!

*May 14, 2010*

**5th grade math**

My class is selling flowers. We want to arrange them so that they are all in equal rows with no row containing different types of plants. Using the numbers from the table provided, what is the largest # of plants we can put in each row? (Marigolds-48 pots, Pansies-24 pots, ...

*May 14, 2010*

**Math**

Oh that makes sense. I forgot to look at the largest common factor. Thank you, I was thinking it was every other and how many can fit onto a tray! Thank you! That may help me in my other problem as well!

*May 14, 2010*

**Math**

It is a story problem. Courtney has 27 chocolate chip cookies and 36 oatmeal raisin cookies. She needs to arrange them on trays. She doesnt want to combine either type of cookies and she wants the same number on each tray. What is the largest number of cookies she can hve on ...

*May 14, 2010*

**algebra**

solve x-5/x*x-54 -7x+8/x*x-3x-54 +x-2-x*x+12x+36

*May 13, 2010*

**algebra 2**

The volume ( v) of a gas in a container at a constant temperature varies inversely as the pressure (p). If the volume of a gas is 24 cubic centimeters when the pressure is 16 pounds, what is the volume under a pressure of 30 pounds?

*May 8, 2010*

**geometry**

A right cylinder has a radius of 3 and a height of 12. What is its surface area? If necessary, round your answer to two decimal places.

*May 4, 2010*

**college physics**

A typical wavelength of infrared radiation emitted by your body is 25 µm (2.5 multiplied by 10-5 m). What is the energy per photon of such radiation?

*April 26, 2010*

**chemistry**

use resonance theory to account for the fact that aniline(pKb 9.37) is a weaker base than cyclohexanamine(pKb 3.34)

*April 25, 2010*

**Chemistry**

1)Write the general equation used to determine the volume of stock required to make a given concentration of standard? Define any terms you used. ----use the 100ml flasks to create four serial dilutions of the stock 10,000uM nitrate solution that has been provided. Prepare ...

*April 23, 2010*

**chemical oceanography**

Avg PO4^3- []'s in the deep and surface ocn's are 2.11 and 0.71umolkg^-1. Calc the residence time of PO4^3- in the deep ocn considering the carbon budget(Figure below) Write the general equation, calculation and units. ------ represents a Box outline Surface...

*April 23, 2010*

**chem 1p1**

An automobile tire at 22oC with an internal volume of 20.0L is filled with air to a total pressure of 30. psi(pounds per square inch). [1 atm = 14.696 lb/in2]. What is the amount in moles of air in the tire? If the air is mostly nitrogen, how many grams of it would be in the ...

*April 23, 2010*

**Chemical Oceanography**

Avg PO4^3- []'s in the deep and surface ocn's are 2.11 and 0.71umolkg^-1. Calc the residence time of PO4^3- in the deep ocn considering the carbon budget(Figure below) Write the general equation, calculation and units. ------ represents a Box outline Surface...

*April 22, 2010*

**Chemical Oceanography**

Avg PO4^3- []'s in the deep and surface ocn's are 2.11 and 0.71umolkg^-1. Calc the residence time of PO4^3- in the deep ocn considering the carbon budget(Figure below) Write the general equation, calculation and units. ------ represents a Box outline Surface...

*April 22, 2010*

**chemistry**

write the two half-reactions for the reduction of nitrate to nitrite using Cd2+

*April 22, 2010*