Friday

December 9, 2016
Total # Posts: 8,165

**physics **

A train moving at a constant speed is passing a stationary observer on a platform. a flute player is playing a note with frequency of 940Hz. after the flute has passed, the observer hears the sound frequency of 915Hz. What is the speed of the train? The speed of sound in air ...

*December 9, 2014*

**Chemistry**

How many liters of stomach acid (pH = 4.000) will be neutralized by a 1.50 g tablet of "Bicar", a commercial tablet which is 50% flavored and 50% NaHCO3? Note that: NaHCO3(s) --> Na+(aq) + HCO3-(aq) and: H+(aq) + HCO3-(aq) --> H20(l) + CO2(g) So far I've ...

*December 9, 2014*

**Math (Simplifying Fraction)**

(x^-1+4x^-2)/(1-16x^-2)

*December 8, 2014*

**mechanics**

what is coefficient of friction of a 25lb object resting on a horizontal surface that requires 10lbs to move?

*December 8, 2014*

**Chemistry; stoichiometry**

Thanks for the advice! I was still getting an odd theoretical yield but that was probably from the data we collected.

*December 7, 2014*

**Chemistry; stoichiometry**

Determine the theoretical yield of silver that is produced if the other product is Copper(II) Nitrate. Copper that reacted: 0.3180 This is what I had: 0.3180g Cu x 1mol Cu/63.5g Cu x 2mol Ag/1mol Cu x 107.87g Ag/1mol Ag = 1.079g Ag (Set up in factor label method)

*December 7, 2014*

**Advance Algebra**

thanks:) mapuan here:)

*December 7, 2014*

**m**

yes, of course! there is no problem to each the kids science everyday! science is a very exciting thing!

*December 6, 2014*

**physics**

what impulse is needed to slow a 45kg object from 15m/s to 12m/s?

*December 6, 2014*

**physics**

steven throws a 3.5kg ball at a speed of 25m/s. what is the momentum of the ball? Please show work

*December 6, 2014*

**physics**

how many significant digits are in the following measurement 2.546m

*December 5, 2014*

**algebra**

how do you write the simplest polynomial function with the given zeros

*December 4, 2014*

**algebra**

how do you write simples polynomial function with the given zero 1-i and 2

*December 4, 2014*

**Chemical Biology**

Which fruits or vegetables or plants do not contain catalase enzyme?

*December 4, 2014*

**math**

deliias car weighs 2 tons how many ounces does the car weigh?

*December 3, 2014*

**algebra**

how to you solve polynomial equation by factoring x^3 + 3x^2 - 9x = 27

*December 3, 2014*

**algebra**

solve polynomial equation by factoring x^4 +100 = 29x^2

*December 3, 2014*

**Language Art Novel**

ms. sue are you a stripper?

*December 3, 2014*

**algebra**

solve polynomial equation by factoring 2x^3 - 12x^2 = 32x - 192

*December 3, 2014*

**algebra**

how do you solve polynomial equation by factoring 3x^4 + 11x^3 = 4x^2

*December 2, 2014*

**physics**

how do you solve 3x^4 + 11x^3=4x^2

*December 2, 2014*

**Chemistry**

carbon dioxide has a henrys law constant of 3.4E-2 mol/l*atm what is the molar concentration of CO2 in water if the partial pressure of CO2 in air is .000387. i know i have to use S=Kh*P but that gives you soluability where do i go from here to find molar concentration of CO2 ...

*December 2, 2014*

**math**

need help please. the time required for one complete oscillation of a pendulum is called its period. if L is the length of the pendulum, then the period is given by P= 2 times pie multiplied by the square root of (L/g), where g is a constant called the acceleration due to ...

*December 2, 2014*

**algebra**

using long division (x^6 - 4x^5 -7x^3) / (2x^3)

*December 1, 2014*

**physics**

a 2.0-kg ball has a momentum of 25 kg*m/s. what is the ball's speed?

*December 1, 2014*

**physics**

a net force of 200 newton's is applied to a wagon for 3 seconds. this causes the wagon to undergo a change in momentum of

*December 1, 2014*

**physics**

a net force of 100 newton's is applied to a wagon for 5 seconds. this causes the wagon to undergo a change in momentum of

*December 1, 2014*

**AP CALC. AB**

A) 1.123m/min

*November 29, 2014*

**Chemistry**

42 J

*November 25, 2014*

**Math 3371**

In a certain year, 26% of all teenagers in the United States had checking accounts. Your bank, TeenChex Inc., is interested in targeting teenagers who do not already have a checking account. (a) If TeenChex selects a random sample of 3,000 teenagers, what number of teenagers ...

*November 24, 2014*

**Business statistics **

Hello, I'm struggling trying to find the answer for b. Do you know the answer and help would greatly be appreciated! A clean air standard required that vehicle exhaust emissions not exceed specified limits for various pollutants. Many states require that cars be tested ...

*November 20, 2014*

**science**

The question is in reference to o2 canisters attached to space suites during space travel

*November 19, 2014*

**science**

What provides pure O2 for inhaling and canisters to collect CO2 CO2.

*November 19, 2014*

**Chemistry**

Are there any substances that are soapy and/or bitter in nature but are not bases/alkali?

*November 18, 2014*

**Chemistry**

Neutralizing acids.

*November 16, 2014*

**Chemistry**

Are there any chemical reactions or observations that involve sodium hydroxide or any other bases, but cannot be used to confirm its basic nature?

*November 16, 2014*

**calculus **

it costs 8 dollars to manufacture and distribute a backpack.If the backpack sell at x dollar each, the number sold , n, is given by n= 3/(x-8)+5(100-x) . Find the selling price that will maximize the profit.

*November 15, 2014*

**safety contest scramble**

Four words. First word (8 letters), second (6 letters) third (four letters) fourth word (9 letters). The letters are oneqplmeiuoraeectttnepsrivp. Any ideas?

*November 13, 2014*

**Physics **

A 5.00-kg block is placed on top of a 12.0-kg block that rests on a frictionless table. The coefficient of static friction between the two blocks is 0.650. What is the maximum horizontal force that can be applied before the 5.00-kg block begins to slip relative to the 12.0-kg ...

*November 10, 2014*

**mathematics**

ssa

*November 10, 2014*

**Physics**

Two masses ( 2.3 kg and 4.2 kg) connected by a massless rope hung over opposite ends of a frictionless pulley. Each mass is initially 1.50 m above the ground, and the top of the pulley is 6.5 m above the ground. What maximum height does the lighter object reach after the ...

*November 9, 2014*

**SCIENCE**

Hello

*November 9, 2014*

**Algebra**

A kayaker paddles upstream for 1.5 hours then turns his kayak around and returns to his tent in 1 hour. He travels 3 miles each way. What is the rate of the rivers current?

*November 8, 2014*

**Chemistry**

How many hydrogen bonds can each (i) water and (ii) ice molecule form?

*November 8, 2014*

**calculus**

find the derivative of y y= 2 (22x+31)^(3/2)+ arctan((22x+21)^(1/2))+ln(11x+16)-22x-30

*November 8, 2014*

**Calculus**

i didn't get what you did can you plzz help me again ?

*November 8, 2014*

**Preschool/Kindergarten**

I agree with Ms. Sue. d is the best choice.

*November 7, 2014*

**Chemistry**

Does the Hydrogen Bondings in ice form, break, and reform all the time, just like in water?

*November 7, 2014*

**chemistry due soon**

so whats the answer???

*November 7, 2014*

**Chemistry**

If 10 cm3 of ethanol is added to 10 cm3 of water, does the initial temperature of water change upon addition of ethanol?

*November 6, 2014*

**chemistry**

Use Table 9.4 to calculate an approximate enthalpy or heat of reaction for the combustion of one mole of methane gas (CH4) to form gaseous H2O and CO2. What Volume (in L) of methane is needed to produce 3287 kJ of heat for methane gas at 11 oC and 3.40 atm pressure?

*November 5, 2014*

**chemistry**

Using Table 9.4, calculate an approximate enthalpy (in kJ) for the reaction of 1.02 g gaseous methanol (CH3OH) in excess molecular oxygen to form gaseous carbon dioxide and gaseous water.

*November 5, 2014*

**chemistry**

A student obtained an average PV value of 42,000 in column (f) of the data table. If the syringe had been able to be adjusted to a volume of 35.0 mL, what would the pressure be inside the flask?

*November 5, 2014*

**ENGLISH 10 HELP!!!**

what motivated Shakespeare to write The Tragedy of Macbeth?

*November 4, 2014*

**MACBETH HELP PLZZ! **

what motivated the Gunpowder Plot of 1605

*November 4, 2014*

**Physics**

A vector is directed at an angle tangent above the +x axis, pointing into the first quadrant. If the x component of this vector is 10 m, the magnitude of the vector is?

*November 4, 2014*

**chemistry**

Draw the dominant Lewis structure for NO2+. Note, that this ion is isoelectronic with CO2. How many double bonds does this resonance structures have?

*November 4, 2014*

**chemistry**

Draw one of the Lewis structure of the N2O5. In each case one oxygen bridges the nitrogens (N-O-N single bond) and 2 other oxygens are bonded to each N. How many equivalent resonance structures are there that satisfy the octet rule and where O makes at most 2 bonds?

*November 4, 2014*

**Chemistry**

How do we use 2 indicators to confirm the pH of a solution?

*November 4, 2014*

**Fraction**

A fruit grower uses 1/3 of his land for bananas,3/8 for pineapples1/6 for mangoes and the remainder for oranges. What fraction of his land is used for oranges?

*November 3, 2014*

**Fraction**

A girl spends 1/4 of her pocket money on monday and 3/8 on wednesday. What fraction of her money is left

*November 3, 2014*

**Algebra 2**

Telephone numbers are made of 7 digits. Digits can be repeated but the first digit cannot be 0 or 1. How many different telephone numbers can be created? I believe you use combination function, but I am not sure how and where.

*November 2, 2014*

**Algebra check?**

ok it wont let me put spaces, sorry! 1. 3i - 10 over 8i - 5 Answer: 74 over 89 + 65 i over 89 2. 11i^2 + 1 over -12i - 8 Answer: 5 (2 - 3 i) over 26

*November 2, 2014*

**Algebra check?**

Sorry the first post formatted weirdly. 1. 3i - 10 --------- 8i - 5 Answer 74 65i ---- + ----- 89 89 2. 11i^2 + 1 ------------ -12i - 8 Answer: 5 (2 - 3 i) ------------- 26 3. square root -25 * 8 square root -49 Answer: -280 4. square root -64 + 12 square root -36 Answer: 80 i...

*November 2, 2014*

**Algebra**

(sorry this formatted weirdly, it's meant to be this if you can't tell) 1. 3i - 10 over 8i - 5 Answer: 74 over 89 + 65 i over 89 2. 11i^2 + 1 over -12i - 8 Answer: 5 (2 - 3 i) over 26

*November 2, 2014*

**Algebra**

Can you tell me if my answers are correct for these problems? 1. 3i - 10 --------- 8i - 5 Answer 74 65i ---- + ----- 89 89 2. 11i^2 + 1 ----------- -12i - 8 Answer: 5 (2 - 3 i) ------------- 26 3. square root -25 * 8 square root -49 Answer: -280 4. square root -64 + 12 square ...

*November 2, 2014*

**physics **

The average car today has a mass of 1100 kg, and when accelerating from rest, covers 0.25 miles in 15 seconds. Each rim and tire together has a diameter of 45.7 cm and a mass of 9.1kg. How many revolutions did one of the front tires (assuming only the back tires spun upon ...

*November 2, 2014*

**math**

let f(x)=-5x+6 find and simplify f(x+2) f(x+2)=___

*October 30, 2014*

**ap chem**

Under certain conditions, the reaction 3 A + 4 B → 5 C is observed to proceed at a rate of 0.0106 M · s−1. What is the corresponding rate of change in product C? 1. 0.0318 M · s−1 2. 0.0106 M · s−1 3. 0.00353333 M · s−1...

*October 30, 2014*

**physics**

Find the x- and y-coordinates of the center of gravity of a 4.00 ft by 8.00 ft uniform sheet of plywood with the upper right quadrant removed as shown in the figure below. The dimensions of the cutout are a = 4.50 ft and b = 1.70 ft. HINTS: Think of the board as being made of ...

*October 28, 2014*

**AP Physics C**

A 4.10 kg block is pushed along a floor by a constant applied force that is horizontal and has a magnitude of 39.0 N. Figure 6-26 gives the block's speed v versus time t as the block moves along an x axis on the floor. What is the coefficient of kinetic friction between ...

*October 28, 2014*

**Physics**

A hiker hikes in a straight line and maintains a constant velocity of +0.5 m/s. At time t=0.0 s, the hiker is 30 m from point A. What is the displacement from point A at 120 s? a. 60 m c. 120 m b. 90 m d. 15 m

*October 28, 2014*

**physics**

thank you so much !!

*October 28, 2014*

**physics **

Two people (from the 1950s!) sit on opposite sides of a uniform board of length L. One person, of mass m1 = 50.0 kg, sits at a point 1.90 m to the left of the fulcrum. The fulcrum is located at the center of the board. The other person, of mass 45.0 kg, sits at a point a ...

*October 28, 2014*

**Calculus **

The top of a 13 foot ladder is sliding down a vertical wall at a constant rate of 4 feet per minute. When the top of the ladder is 5 feet from the ground, what is the rate of change of the distance between the bottom of the ladder and the wall

*October 27, 2014*

**physics **

A person is kayaking in the ocean at 5.6 m/s 75° to the horizon when he experiences a current of 3.8 m/s 45° south of west. What is the speed and direction of his kayak?

*October 26, 2014*

**mathematics**

the lenght of a rectangle is twice its width.If the width is reduced by 1cm and the lenght is also reduced by 2cm,the area will be 15cm(square).Find the dimensions of the original rectangle.

*October 26, 2014*

**maths**

A deck has 52 cards it has 13 in each type find the probability of getting a) a diamond card b) an ace card c) a red card d) a yellow card e) getting any card

*October 25, 2014*

**English II**

Compare the literary and rhetorical devices in Elie Wiesel's Nobel Peace Prize Acceptance Speech and his novel Night. Explain how these elements impact tone and mood. Support your claims with evidence from the text.

*October 23, 2014*

**physics**

A baseball is thrown at an angle of 20◦ relative to the ground at a speed of 25.6 m/s. The ball is caught 42.9416 m from the thrower. The acceleration due to gravity is 9.81 m/s2 . How long is it in the air?

*October 23, 2014*

**world history**

How did Europe’s geography/advantages lead to its rise as a global power?

*October 20, 2014*

**physics**

A triple beam balance, like the scales we use every week in lab, works using rotational equilibrium. If a 253 g mass is placed on the pan, 1 cm from the pivot, and there are three masses, 1 g, 10 g, and 50 g masses on the other side can be slid back and forth between 0 cm and ...

*October 18, 2014*

**Human Relation - HELP!!!**

Why parents considered as our role models?

*October 18, 2014*

**Math**

Do you need to regroup to find 73-35? Explain your answer.

*October 16, 2014*

**Math**

A plane takes off from a local airport. It travels due north at a speed of 400km/h. The wind blows the plane due east at a speed of 50 km/h. How far is the plane from the airport after 1h. Give your answer to one decimal place

*October 15, 2014*

**Math**

I Cant tell you the answer. you should be able to figure the answer by yourself. ill be glad to check your work

*October 15, 2014*

**Basic Statistics**

A researcher is interested in estimating the average salary of police officers in a large city. She wants to be 95% confident that her estimate is correct. If the standard deviation is $1050,how large a sample is needed to get the desired information and to be accurate within...

*October 15, 2014*

**Basic Statistics**

A random sample of 16 mid-sized cars tested for fuel consumption gave a mean of 26.4 kilometers per litre with a standard deviation of 2.3 kilometers per litre. (a)Assuming that the kilometers per litre given by all mid-sized cars have a normal distribution,find a 99% ...

*October 15, 2014*

**Statistics**

The points of 100 children in a test are normally distributed with mean of 25 points and a standard deviation of 10 points. (a)Given that the passing mark is 20, estimate the number of children who passed the test. (b)If 5.59% of the children obtain a distinction by scoring x ...

*October 15, 2014*

**Sales**

Indeterminate

*October 14, 2014*

**Math**

A water tank will be drained at a constant rate of 42.4 liters per hour starting at 9:00 A.M. After one hour, the change in the amount of water in the tank can be represented as –42.4. Which of the following represents the total change in the amount of water in the tank ...

*October 14, 2014*

**math**

how do i work this problem 8x25x23 using subtraction in mental math

*October 14, 2014*

**physics**

A truck with mass 2000 kg tows a boat and trailer of total mass 500 kg. The rolling coefficient of friction for the truck is 0.080 and for the trailer is 0.050. The force of the truck’s drive wheels pushing backward on the pavement is 3.0 kN. (a) Determine the ...

*October 14, 2014*

**Math**

If john makes 60 k a year , how much does he make each month?

*October 14, 2014*

**Chemistry**

Cambridge uses FA 1, FA 2 etc to name chemicals or solutions. What does FA stand for?

*October 13, 2014*

**physics**

Two crewmen pull a boat through a lock, as shown in Figure 5-25. One crewman pulls with a force of F1 = 155 N at an angle of θ = 32° relative to the forward direction of the raft. The second crewman, on the opposite side of the lock, pulls at an angle of 45°. With...

*October 11, 2014*

**Physics**

A pilot gets into trouble flying 2000m above the pacific ovean. He flies 550 km/h [S 30(degree)W] with a wind from the NW of 100 km/h. he ejects himself at a velocity of 10m/s [upwards]. What is his velocity at the instant he hits the ocean surface? Express your answer in km/h.

*October 11, 2014*