Sunday

May 29, 2016
Total # Posts: 623

**Physics**

A circuit employs a silicon solar cell to detect flashes of light lasting 0.25 s. The smallest current the circuit can detect reliably is 0.32 μA . Assuming that all photons reaching the solar cell give their energy to a charge carrier, what is the minimum power of a ...
*May 6, 2016*

**math**

Cynthia has a bag of jellybeans. There are two red jellybeans, one yellow jellybean, and two black jellybeans in her bag. Cynthia grabs two jellybeans and gives them to her friend, Pedro, and he eats them. What is the probability that she gives him two red jellybeans?
*May 3, 2016*

**Physics mechanics**

Two identical 17.7-kg balls, each 23.9 cm in diameter, are suspended by two 35.0-cm wires as shown in the figure (Figure 1) . The entire apparatus is supported by a single 18.0-cm wire, and the surfaces of the balls are perfectly smooth. what is the tension in the top wire?
*February 8, 2016*

**math**

two boats p and q are at points whose position vector are 4i+8j and 4i+3j respectively. both of the boats are moving at a constant velocity of p is 4i+j and q is 2i+5j. find the position vectors of p&q and pq after t hours, and hence express the distance between p and q ...
*February 6, 2016*

**Math**

20 black tiles
*February 6, 2016*

**chemistry**

200cm3 of each of 0.1m of solutions of lead (ii) trioxonitrate (v) and hydrochloric acid were mixed. Assuming that lead (ii) chloride is completely insoluble, calculate the mass of lead (ii) chloride that will be precipitated.
*January 8, 2016*

**fourth grade math**

After making a dot plot, Julie asked Kevin what size shoe he wore. She then added together the total of all the shoe sizes including Kevin's. The total was 139. What size shoe does Kevin wear?
*January 7, 2016*

**trigonometry**

Nikki bought a triangular lot whose sides are 9 meters, 12 meters, and 15 meters long. if it cost her 3500 pesos per square meter, how much did she pay for the lot?
*December 28, 2015*

**Health**

You may need to see a doctor if ________.
*December 15, 2015*

**Health**

How long do anxiety disorders last? A .at least two years b. at least one year c. at least 6ix months d. at leaks 6 weeks D?
*December 15, 2015*

**Physics**

The temperature of 2.0 g of helium is increased at constant volume by ΔT. What mass of oxygen can have its temperature increased by the same amount at constant volume using the same amount of heat? I know for constant volume I should use the equation: Q=mCsubvdeltaT I ...
*December 2, 2015*

**scale drawing**

the distance betw two towns on a map is 15cm calculate the ground distance if the scale of the map is 1:50,000
*November 17, 2015*

**math**

I am having problems starting of the equation . I understand how to do it but have a hard time setting it up correctly.
*November 16, 2015*

**math**

a rectangle has a width of one less than the length . if the perimeter is 30 units , what is the length and width ?
*November 16, 2015*

**math**

according to information from NASA, the space shuttle has a capacity of about 500,000 gallons of fuel. Write three numbers that could represent the space shuttle's actual fuel capacity? I don't understand the question.
*November 11, 2015*

**math**

if a person walks 2.4 miles in 1.5 hours, how far can he walk in 3hours
*November 10, 2015*

**math**

Ms.Sue I did $10 divided by 4.5 pounds to get 2.22222 repeating. i rounded it and got 2.22 dollars
*November 10, 2015*

**math**

if 4.5 pounds of cherries cost $10, what is the unit price per pound
*November 10, 2015*

**math**

Ms.Sue i still dont get this problem may u explain
*November 10, 2015*

**math**

If a person walks 2.4 miles in 1.5, how far can he walk in 3 hours
*November 10, 2015*

**Science**

pH values of 12,6,10.5 and 4.3.which of these is acidic and basic
*October 30, 2015*

**Math **

Which of the following is equal to the expression below?
*October 28, 2015*

**math**

A merchant purchased a number of coats, each at the same price, for a total of $720. He sold them at $40 each, thus realizing a profit equal to his cost of 8 coats. How many did he buy
*October 15, 2015*

**math**

It takes B 6 hours longer than A to assemble a machine. together they can do it in 4hr. how long would it takes each worker alone to do job
*October 15, 2015*

**MATH HELP PLEASE**

math
*October 9, 2015*

**Programming**

using c++ write a program that accepts the unit weight of a bag of coffee in pounds and the number of bags sold and display the number of bags sold ,the weight per bag price per pound sales tax and total price of the sale.the unit of a bag of coffee is valued as $5.99 pound ...
*October 7, 2015*

**Science**

he is right
*October 7, 2015*

**Physics**

Horse canters away from its trainer in a straight line moving 130 m away in 16.0 s. It then turns abruptly and gallops halfway back in 4.3 s? (a) Calculate its average speed. (b) Calculate its average velocity for the entire trip, using "away from the trainer" as the...
*October 6, 2015*

**Mathematics **

two brothers Peter and Paul owns a store. if there share ratio of store value 3 ratio 5, later peter sold 2/3 of his share to Paul for 8000 naira. what is the value of the goods in the store.
*September 30, 2015*

**reading**

30-day Money Back Guarantee Groom Co. electric shavers come with a 30-day money back guarantee. The only stipulation is that you use your new exclusively for 2 weeks to become accustomed with the product. If you are not satisfied, we will refund the amount on your receipt if ...
*September 27, 2015*

**english**

???
*September 27, 2015*

**english**

30-day Money Back Guarantee Groom Co. electric shavers come with a 30-day money back guarantee. The only stipulation is that you use your new exclusively for 2 weeks to become accustomed with the product. If you are not satisfied, we will refund the amount on your receipt if ...
*September 27, 2015*

**Statistics**

If 50 classes of 20 students are randomly selected, what is the probability that 10 classes have no left handed students? I know it is binomial distribution but i do not get it
*September 8, 2015*

**Early Literacy**

Preschoolers usually begin to add tag endings, such as "huh?" and "okay?" to their questions around age:
*June 3, 2015*

**Math**

If 7 1/4 boxes of parts weigh a total of 68 7/8 pounds, what does one box of parts weigh?
*May 30, 2015*

**American Government**

The voting rate among 18 - 24 year olds in 2004:
*May 25, 2015*

**American Government**

The fourth branch of government refers to
*May 25, 2015*

**math**

Tess’ commission is increased according to how much she sells. She receives a commission of 6% for the first $5000 and 12% on the amount over $5000. What is the total commission on sales of $12,000?
*April 26, 2015*

**Engineering Physics 1**

I shot the first arrow Into the air with a speed of 10 m/sec , 1 second later I shot the 2nd arrow into the air with a speed of 15 m/sec. Will they meet? If so, where? how do i solve this?
*April 26, 2015*

**benedicta**

tap A takes 12min to fill a tank with water tap B takes 15min to empty the same tank if the two taps are open at the same time how long will it take
*April 23, 2015*

**ss**

the aztec capital of tenochtitlan stood on the present-day A.Los Angeles B.Panama City C.Mexico D.Tikal
*April 17, 2015*

**math**

about the same amount of rain fell 2 months ago like last month
*April 13, 2015*

**geometry**

A train in the mountains rises 10ft for every 250ft it moves along the track. Find the elevation of the track.
*March 25, 2015*

**Art**

yes i go to connections
*March 16, 2015*

**math**

Not sure where you got 360 from?
*March 5, 2015*

**Religion**

God does this so when he makes all things right and new he gets the glory, i know that sounds weird but look at the holocaust all those Jews who died most of them went to heaven then he set them free, then he gave them isreal back. i was in a car accident i broke my collar ...
*March 4, 2015*

**Health**

Miss Nancy, those are all wrong. I took the test.
*February 27, 2015*

**social studies 8 ANSWER PLEASE!!!!!!!!**

The National Road
*February 5, 2015*

**Chem Uni. Urgent!!!**

Thanks a lot, I obtained 0.85 g as well. Concerning the 0.50g, few crystals were lost during handling.
*February 3, 2015*

**Chem Uni. Urgent!!!**

Have to find theoretical yield of recrystallization of acetanilide from water. 1 gram of crude product used (85% acetanilide, 14% Sodium chloride and 1% charcoal) I got 0.50 grams of purified product. With percent recovery of : (0.50g/1.00g)* 100% = 50%. How do I find the ...
*February 3, 2015*

**Math**

.248... is the volume of the basketball in ft^3. A cubic foot has 1 ft^3 of volume. Subtract .248 from 1 ft, you get .7515 ft^3 Multiply .7515 by 62.4 lb = 46.895 lbs
*January 30, 2015*

**Calculus**

Determine the interval(s) at which f(x) is concave up given that f′′(x)=−x2+x+6. a) (–2, 3) b) (–∞, –2), (3, ∞) c) (–∞, –3), (2, ∞) d) (–2, ∞) e) (–∞, 3)
*January 30, 2015*

**Calculus **

Determine the interval(s) at which f(x) is concave up given that f′′(x)=−x2+x+6. Critical points are: -2 & 3
*January 30, 2015*

**Ionic compounds Scinece**

3. What happens to the change on individual ions when they form ions? 11. Write the names of the two ions in each of the following compounds. (C) Na2O (E) Na3PO4 (G) NH4OH (H) Ca (NO3)2 8. Use the tables of metals, non-metals, and polyatomic ions and the Periodic table to name...
*January 22, 2015*

**Chemistry**

Perchloric acid, HClO4, is a strong acid. What are the pH values of the following solutions: a) 3 M perchloric acid b) 0.1 M perchloric acid c) 0.001234 M perchloric acid d) 10-5 M perchloric acid e) 10-9 M perchloric acid is the pH -log(conc. ?
*January 19, 2015*

**Chemistry**

a solution of HCL is approximately 0.1M and has to be standardized . 1.234g Na2CO3 are dissolved to make 100ml of solution. 20mL of this solution are titrated with the HCL solution, requiring 31.3mL for the second equivalence point. what is the exact concentration of the HCL ...
*January 14, 2015*

**Chemistry**

Draw the pH-titration curve for the following, label x and y axes accordingly. 10 mL of 0.1M H3PO4 with 0.1 M NaOH (Logk values = 2, 7, 12) I understand that the x-axis is mL of H3PO4 added and y-axis is the pH. But the logK values, is that the equiv-points for the tri-protic ...
*January 14, 2015*

**Chemistry (Chromatography)**

Comment on the order of elution of the following solutes in (a) normal phase and (b) reversed phase liquid chromatography. Give reasons why. Solute X - non-polar Solute Y- Polar, a dipole Solute Z - Polar, more polar than solute Y I understand that polarity is the reason of ...
*January 13, 2015*

**Chemistry (Chromatography)**

In elution chromatography (Ion-exchange) outline the order of elution for the following cationic species: Cu2+, Fe3+, Ag+ and Na+? I understand it has to do with polarity, but in which sense i.e does the least polar/most polar species elute first? Thanks
*January 13, 2015*

**Chemistry**

Thanks for the time and help, this was my final working out, don't know if you will receive this, so once again thank you. Step 1: moles Na2CO3 = 1.234g/105.89 g/mol = 0.0116 mol. Step 2: 20mL of Na2CO3 = 0.0116*(20/100) = 0.00232mol/L Step 3: Balanced equation = Na2CO3 + ...
*January 9, 2015*

**Chemistry**

a solution of HCL is approximately 0.1M and has to be standardized . 1.234g Na2CO3 are dissolved to make 100ml of solution. 20mL of this solution are titrated with the HCL solution, requiring 31.3mL for the second equivalence point. what is the exact concentration of the HCL ...
*January 9, 2015*

**PHYSICS**

A 209 kg block is released at height h = 3.3 m as shown. The track is frictionless except for a portion of length 7 m. The block travels down the track, hits a spring of force constant k = 1545 N/m, and compresses it 1.9 m from its equilibrium position before coming to rest ...
*December 10, 2014*

**physics**

A student, late for class, ran up some stairs between landings, which are 11.3 m apart. The student’s mass is 62 kg and it took 6.02 s to do the run. What is the average power that the student generated during the run?
*December 10, 2014*

**Math**

What are the comparisons between the mixed numbers 5.815 and 6.021
*December 10, 2014*

**Math**

I don't know the answer
*November 28, 2014*

**Calculus**

Find the volume of the solid obtained by rotating the region bounded by the curves: 2x = -y^2 y^2 = -x + 2 y = 0 for y >= 0 about the x-axis. Not sure how to do this one, could anybody help me identify what this looks like and how to identify the outer/inner radius? Thanks
*November 23, 2014*

**Calculus**

Thank you!
*November 23, 2014*

**Calculus**

Scratch that, I received the answer of 11pi/30, I made a calculation error that first time. Is this correct?
*November 23, 2014*

**Calculus**

Find the volume of the solid obtained by rotating the region bounded by the curves: y = x^2 and x = y^2 about the line y = 1. I received the answer pi/30, using the outer radius of (1 - x^2) and the inner radius of (1 - x^(1/2)). Is this correct?
*November 23, 2014*

**Calculus**

This is the question: i[dot]imgur[dot]com/EHneTuB[dot]jpg Am i correct in simply adding 1 + (-3), and equates to (-2) being the answer.
*November 16, 2014*

**Calculus**

If I derive the following, d/dt((a)S(t^2) of (s)^(1/2)ds with S being integral notation (a) being at the bottom of the notation and being a constant (t^2) being at the top of the notation ..I first apply the fundamental theorem of calculus to get.. (t^2)^(1/2) (2t) simplified ...
*November 16, 2014*

**Calculus**

Ah Thanks!
*November 15, 2014*

**Calculus**

Thanks Steve. Does that mean the function is not odd? I thought odd functions are always integrated to = 0 because of their symmetry.
*November 15, 2014*

**Calculus**

This is a definite integral question. Evaluate the following integral: (0)S(a)((x)((a^2 - x^2)^(1/2)))dx with a being a constant and the (0) being at the bottom of the integral notation and (a) at the top. S is the integral notation. I firstly checked whether the function was ...
*November 15, 2014*

**Calculus**

Find f"(x). f(x) = x^3 - (5/x)
*November 11, 2014*

**algebra**

If 3.14*r^2=706.5? what does r=?
*November 11, 2014*

**calculus**

How did you get that Damon? I thought I could only reorder question as e^x/(1/x) and apply hopital rule from there
*November 8, 2014*

**calculus**

This is a question related to L'hopital's rule. lim x -> -infinity of ((x)(e^x)) This thing is weird because I apply l'hopital's rule yet I never receive the correct answer which is supposedly = 0. It just stays in the form [-infinity * -infinity]. Anyone ...
*November 8, 2014*

**Calculus**

This is a question related to L'hopital's rule. lim x -> -infinity of ((x)(e^x)) This thing is weird because I apply l'hopital's rule yet I never receive the correct answer which is supposedly = 0. It just stays in the form [-infinity * -infinity]. Anyone ...
*November 8, 2014*

**Algebra**

You earn $250 per month from your part-time job. You are in a kayaking club that costs $20 per month, and you save at least $100 each month. Write and solve an inequality to find the possible amounts you have left to spend each month.Can someone please help me with this
*October 22, 2014*

**Spanish Check**

I understand completely now! Thank you for your help :)
*October 12, 2014*

**Spanish Check**

Can you tell me if any of my answers are wrong, and if so which/why? Instructions: Choose por or para to fill in the following phrases; 1. Compré las flores __________ mi novia. Compré las flores para mi novia. 2. Hice la tarea __________ la tarde. Hice la tarea ...
*October 12, 2014*

**math**

eva wants to make two pieces of pottery. She needs 3/5 pound of clay for one piece and 7/10 pound of clay for the other piece. She has three bags of clay that weigh 4/5 pound a piece. How many bags of clay will eva need? How many pounds of clay will she have left over?
*October 6, 2014*

**Calculus**

why does the line have to cross (h, ln(h))?
*September 27, 2014*

**Calculus**

ah thank you steve
*September 27, 2014*

**Calculus**

My professor claims that it is solvable because it says that the point (0,0) lieS on a tangent line to the graph y=ln(x) at some point (a,b)
*September 27, 2014*

**Calculus**

Hello, my question is the following: The derivative of f(x) = ln(x) is given by f'(x) = 1/x. Find an equation of the tangent line to the graph y = ln(x) that passes through the point (0,0). So if I go through this using the typical method I use I have the point slope ...
*September 27, 2014*

**math**

A student is attempting to factor a polynomial. Sample mathematical work is shown below. Which statement best applies to the sample mathematical work? Given 3x + 6, the factors of the first term are 3 and x, and the factors of the second term are 1, 2, 3, and 6. Thus, the ...
*September 22, 2014*

**math**

Q: Suppose that for all xE(0,5), f(x) is between 1+x and 3+sin((pi)(x)). Find lim x->2 f(x). Is this question related to the intermediate value theorem? It is confusing me, can anyone help out? I am not certain of what xE(0,5) is defining, is that a set of x values or am I ...
*September 21, 2014*

**Physics**

A steel ball is dropped onto a hard floor from a height of 1.80 m and rebounds to a height of 1.64 m. (Assume that the positive direction is upward.) (a) Calculate its velocity just before it strikes the floor. m/s (b) Calculate its velocity just after it leaves the floor on ...
*September 17, 2014*

**Physics **

A swimmer bounces straight up from a diving board and falls feet first into a pool. She starts with a velocity of 3.00 m/s, and her takeoff point is 1.10 m above the pool. (a) How long are her feet in the air? s (b) What is her highest point above the board? m (c) What is her ...
*September 17, 2014*

**Science**

I think the answer is d output.
*September 16, 2014*

**Analytical CHM **

Rank the following items in order of accuracy when they are used for their intended purpose: Volumetric pipet, beaker, Erlenmeyer flask, MOHR pipet, graduated cylinder, volumetric flask, buret. Explain your asnwer below Most accurate 1. 2. 3. 4. 5. 6. Least accurate 7. ...
*September 5, 2014*

**Physics**

$53,240.60
*August 27, 2014*

**Grammar**

What is the simple subject and predicate in the sentence: They reach up to 60 inches tall, or 5 feet!
*August 19, 2014*

**auto repair technician**

Is there anyone taking the automobile technician course in penn foster wanting to team up to study together. I'm having trouble with exam #004846
*August 19, 2014*

**life science**

Why this fossils are important discoveries? They have features similar to homo sapiens, and the provide more information about the evolution of humans.
*July 31, 2014*

**Physics**

how much does a 2 lietr bottle of soda pop weigh in pounds? assume that the pop has the density ofg water,namely 1 kg\lietr and that the weight of the bottle itself is negligible?
*July 14, 2014*

**Chem**

A mixture is prepared by adding 28.6 mL of 0.169 M Na3PO4 to 39.7 mL of 0.255 M Ca(NO3)2. What mass of Ca3(PO4)2 will be formed?
*July 1, 2014*