# Posts by jamie

Total # Posts: 1,089

**Calculus II**

Find the derivative of 5^(x^3+x) I know the answer, it's: 5^(x^3+x)*ln(5)*(3x^2+ 1) I just need some help on how to derive that. What rule is at work here? where did the ln come from?

**Economics - Finance**

Your first baby was born yesterday and is healthy and strong. To guard against your premature death, you want to purchase a life insurance policy that will replace $58,000 of your annual income until your child is 20 years old. How much life insurance should you purchase, if ...

**Chemistry **

A chemist makes a solution of K2SO4 by dissolving 21.7 g K2SO4 in water to make 100.0 mL of solution. What is the concentration of SO42? ions in the solution? Assume that K2SO4 is the only solute in the solution. The molar mass of K2SO4 is 174.27 g/mol.

**Math**

Thank you. The answer is 34%?

**Math**

THe Acme Industrial Tech College has fallen on hard times. Last year its enrollment dropped by 20%, and this year enrollement dropped another 15% from last years. Next year the college expected to have 50% of this years enrollment. What percent of enrollment can be expected to...

**Chemistry - Stoichiometry/gases**

Ah, Okay. Thanks!

**Chemistry - Stoichiometry/gases**

When 2.38 g of methane burns in oxygen, 119 kJ of heat is produced. What is the enthalpy of combustion (in kJ) per mole of methane under these conditions? Your answer will be in kJ/mol. the Molar Mass of methane is 16.04, so I did 2.38g/16.04=0.14838 mol Then I did 119 kj/0....

**Calculus 2**

Determine the first three terms of the power series representations for the following functions: a) 2/(1+x)^3 b) 1/1+x^2 c) ln(1+x)

**Calculus 2 - Indeterminant forms**

lim (2^x-3^x)/(cos(x)-1) x->0 The answer the book has for this is "diverges." I know I'm supposed to use L'Hospitals' rule, but I'm not sure how. Can you walk me through the steps?

**Chemistry**

Ah, Okay. Thank you so much for your help. I'll be sure to pay more attention to that in the future.

**Chemistry**

Huh... that's weird then. I ended plugging this in: ln(56.1/101.325)=(29820/8.314)((1/T2)-(1/380.85)) And solved -0.59119=(29820/8.314)((1/T2)-(1/380.85)) to get 349.93. Then I subtracted 273.15 to get 76.78 C.

**Chemistry**

Okay, I wasn't converting kPa to atm. That was the problem. I got 76.8 C, and that was the right answer. Thank you for your help!

**Chemistry**

yeah, I did that. I've got P1=65.1 P2=56.1 T1=330.85 K T2=? H=29,830 j/mol Plugging this in, I got 40.6. But my HW system isn't accepting it.

**Chemistry**

At 57.7°C, the vapor pressure of CCl4 is 56.1 kPa, and its enthalpy of vaporization is 29.82 kJ/mol. Use this information to estimate the normal boiling point (in °C) for CCl4.

**Chemistry - thermochemistry**

Hydrogen gas (H2) is generated by the following reaction. Ca(s) + 2 HCl(aq) ? CaCl2(aq) + H2(g); ?H = ?542.7 kJ/mol When this reaction takes place in a cylinder (fitted with a piston) containing 1.000 mol Ca(s), 542.7 kJ heat is lost to the surroundings. Because a gas is ...

**Chemistry - Kinetic Molecular Theory**

I found an online calculator to check the work, and it gave me 1.086 g/L, which the HW system accepted. I don't really understand what I did wrong... It seems to depend on how I enter it into my calculator: (0.97763*23.036)/(0.08205746*285.35) gives me 1.086 (0.97763*23....

**Chemistry - Kinetic Molecular Theory**

Question: What is the density (in g/L) of ethyne gas at 743 torr and 12.2°C? The unrounded molar mass of ethyne is 26.036 g/mol. I did some unit conversions, so 743 torr=0.97763 atm and 12.2°C=285.35°K I used the equation d=PMr/RT and I plugged in values to get d=(...

**Economics - Formula Help**

Instead of spending the $50 a month you receive, you decided to invest it in your money market account at your bank. Assuming you will earn an average of 5% each year and inflation is forecasted to 2.5% a year, how much have you effectively earned after ten years? (Hint: must...

**Economics**

If there was a baby boom of Oompa Loompas ready to work for free, what will happen to the Willy Wonka chocolate market? In particular: Has this affected supply or demand of Willy Wonka Chocolate? What has happened to the price of Willy Wonka chocolate? Please describe the ...

**Chemistry**

If the maximum velocity v of an electron in copper wire is about 2.0x10^8 cm/s, with an uncertainty ? 1%, how accurately can the electron's position be determined? In other words, what is the uncertainty in the position of the electron (in meters)?

**Math Probability**

A number cube is rolled 450 times. The number 3 comes up 67 times. What is the theoretical and experimental probability of rolling a 3 ? I think the answer is 2/9 but not sure of the process. Can someone explain to me. Sorry to be so much trouble. Thanks

**Math Probability**

You mix the letters M,A,T,H,E,M,A,T,I,C,A and L, thoroughly, Without looking , you draw one letter. Find the probability P(A). Write the probability as: A) fraction in simplest form B) a decimal C) a percent there are 3 letter A"s, so my answers are A)1/4 B).25 C) 25% can...

**math**

From a barrel of colored marbles, you randomly select 5 blue, 2 yellow, 3 red,4 green, and 2 purple. Find the experimental probability of randomly selecting a marble that is NOT yellow. 1) 9/16 2) 7/8 3) 8/9 4) 3/4 I think 7/8 Thanks.

**Chemistry - Significant Figures**

Suppose it takes 35 min for 2.4 g of sugar to completely react with another reagent we added to the flask. What would the reaction rate be? Calculate to the correct number of significant figures.

**math**

Thanks, I went a little foggy.

**math**

A single, standard number cube is tossed. What is the probability of getting a number greater than 3? 1) 2/3 2) 1/3 3) 1/6 4) 1/2 I think 1/2 Thanks

**math**

C is the correct answer...thanks for helping me.

**math**

A coin is flipped 3 times. How does the P (H,H,H) compare to P(H,T,H) ? 1)P (H,H,H) is greater than P(H,T,H) 2) P(H,T,H) is greater than P(H,H,H) 3)The probabilities are the same 4)There is no way to tell with the info given I think #4 is correct...can you advise? Thanks

**math**

A coin is tossed and a number cube is rolled. What is P(heads, a number less than 5)? 1) 1/3 2) 5/12 3) 2/3 4) 5/6 I think #2...can you check?

**Math Probability**

The probability of having a winning raffle ticket is 20%. If you bought 50 tickets, how many wining tickets should you expect to have? 1)3 tickets 2)8 tickets 3)10 tickets I think #3 Thanks

**Math Probability**

You roll a number cube 20 times. It lands on 2 five times. What is the experimental probability of rolling a 2? 1}40% 2)10% 3)25% 4)17% I think #3 Thanks

**math**

Which of the following is a certain event? 1) rolling a composite number on a number cube 2)rolling a number greater than 1 on a number cube 3)rolling an odd or even number on a number cube 4)rolling an odd or even number greater than 7 I think # 3 Thanks for your hrlp

**Science**

A kitchen ceiling light has five lightbulbs on it. When one of the lights goes out, the other four will stay lit. This is an example of a series circuit. True or False I think FALSE because a series circuit would make them all go out.

**Science**

Electric charges that are different? 1)attract each other 2)repel each other 3)exist in pairs 4)do not interact I think #1 Thanks

**Art**

Which of the following items is the best example of functional art? 1)stones 2)a vase 3)paper clip 4)rag I think #1 Thanks

**Health**

Thank you for the website, after reading it, I will go with the #1 answer. Like my book, it also says malnutrition, organ damage and total dependence on the drug.

**Health**

Which statement is true about stage 3 of alcoholism? 1)malnutrition and liver and brain damage often occur 2)Teenagers go through this stage very slowly 3)The drinker becomes totally dependent on the drug 4)The drinker begins trying to escape the everyday stressors. I think #1...

**English**

Thanks, but I did check the meaning of careening( swiftly and uncontrollable) but 3 of the answers were so close, I could not decide. I have changed my answer to #2 Thanks for being so nice.

**English**

The truck was "careening" around the sharp curves of the road as it made its way down the steep mountainside. Which is best definition of the word "careening"? 1)spinning wildly 2)hustling rapidly 3)lurching dangerously 4)wandering aimlessly I think #1 ...

**Art**

An Art critic writes the following comment about the seventeenth century painting. "The Dutch is a master of light and composition." This statement is an example of what stage of critique? 1)describe 2)analyze 3)critique 4)judge I think #4 The reason I think this is ...

**social studies**

Agricultural activities in the Pampas most supports? 1) cacao farming 2) coffee farming 3) silver mining 4) cattle ranching I think #4 Thanks

**ART**

Which object would be the best addition to a collection of writing instruments that are unique to the twentieth century? 1) a pencil 2)a computer 3)a crayon 4)a calligraphy pen I think#2 Thanks for your help

**English**

Choose the meaning of "carvorted" in the sentence. The children carvorted about when the teacher played their favorite music. 1)mingled 2)frolicked 3)tumbled 4)waved my answer is #2....thanks for your help.

**Science**

One light bulb in a string of lights goes out. This causes all the other lights in the string to also go out. This is an example of a?? 1) resistor 2)parallel circuit 3)closed circuit 4)series circuit I think #4. Thanks in advance for your help.

**English**

So I already post a question however I forgot to write the definition of "conventional phrases" so here it is:Meaning beyond literal meaning Ex. – if a character is making his/her bed or making the bed narrow, the speaker is preparing for death My questions are ...

**English**

I need help finding conventional phrases in the Ballad of Birmingham by Dudley Randall that could add to the mood of suspense and tragedy.

**math**

Identify the dependent variable in the relationship. A person burns a total of "c" calories by walking "m" miles. 1)calories 2)miles 3)neither "c" calories or "m" miles 4) both "c" calories and "m" miles I THINK #2, ...

**SS**

The monumental cities of the Incas demonstrated their? 1)extensive trade networks 2)high level of organization 3)interest in astronomy 4)dependence on farming I THINK #2 Thanks in advance for your help.

**English**

Thanks, Ms. Sue # 2

**English**

What is the prepositional phrase in the sentence? Put the lasagna in the oven tonight if you don't mind. 1) put the lasagna 2) in the over 3) the oven tonight 4) if you don't mind I think #1

**SS**

If you were to move to the PAMPAS, where would you most likely find a job? 1)in the silver mines 2)on a cattle ranch 3)on a coffee plantation 4)in the fisheries I think #2

**SS**

How does elevation impact ecosystems in SOUTH AMERICA? 1)farmers can grow different crops at different elevations. 2)plants do not grow above tree lines 3) animals cannot live in higher elevations 4)humans settle only in the lowest elevations I THINK #1

**Science**

Which of the following describes an example of land reclamation? 1) after an area is mined for copper, the soil is replaced and new plants are planted. 2)after a forest is clear-cut, desertification occurs. 3)after a forest is clear-cut, it is mined for copper 4)after an area ...

**SS**

Which of the following is a source of photochemical smog? 1)fossil fuels 2)wind energy 3)biomass fuels 4)nuclear energy I THINK 4

**Science**

Which of these is an example of a biomass fuel? 1) oil 2) natural gas 3) wood 4) coal I think #3

**ART**

A community artist creates a mural of the surrounding farm country. far-off hills, trees, and buildings are slightly blurry and lighter in color than the objects in the foreground. What type of perspective did the artist use in the painting? A:linear perspective B:atmospheric ...

**ART**

Grieving and surrounding the body of a deceased loved one is an example of what art? 1)a cultural rule 2)a community norm 3)an uncommon ritual 4)a community job I think #1

**math**

How do I find vertex, focus and directrix for the following functions? y^2?16y=12x?8^2 x^2+16x=4y?24 (x?2)^2=12(y?2)

**Calculus**

Write the following function as the sum of an odd and an even function. Then calculate the integral over the given interval using the properties of odd and even functions. (x-1)^3, I=[-1,1]

**Statistics**

Could anyone help me out with the following problem? Identify the consequences (i.e. increase, decrease, or none) that the following procedures are likely to have on both bias and sampling error in an experimental study. A) Assigning treatments to subjects alphabetically, not ...

**math**

Find the product.11X(-3)X(-5) equals. 1) -165 2)-28 3) 28 4) 165 I think 4 Thanks

**math**

Which of the following could be represented by -8? 1) a drop of 8 meters 2) 8 T-shirts 3) sea level in 8 places of the world 4) 8 degrees C above 0 I think #1 Thanks

**social studies**

What circumstance had the most direct impact on European colonization of Caribbean South America? 1) the slave trade in Africa 2) the fur trade n Europe 3) piracy in the Caribbean Sea 4) rumors of gold in El Dorado I think 4 but not sure Thanks for your help

**social studies**

What geographic features lies east of the Andes Mountains? 1) saltwater grasses 2)active volcanos 3)llanos grasslands 4)mangrove swamps I think 3 Thanks

**History**

According to their definitions, I would think C (Laissez-faire) is the best option.

**social studies**

Areas of Mexico that can support agriculture are most affected by variations in ? 1) altitude 2) longitude 3) attitude 4) animal species I think altitude

**Grade 11 Math**

A uniform-width boardwalk is built around the inside edge of a rectangular parkland that is 30 m by 5 m. If the boardwalk takes up 20% of the lot, how wide is the boardwalk to the nearest centimetre? I know that the total area= 150m^2 boardwalk area= 30m^2 and the parkway area...

**english**

What are the literary devices used here? "I am frightened: I dare think this way no more. This way lies the abyss. It is not now the time but I will not lose these thoughts, I will keep them, shut them away until the war is ended. My heart beats fast: this is the aim, the...

**math**

A flagpole at right angle to the horizontal is located on a slope that makes an angle of 12? with the horizontal. The pole's shadow is 16 meters long and points directly down the slope. The angle of elevation from the tip of the shadow to the sun is 20?. What is the height...

**Please Help**

(?6)?(a+2b?3c?4d)?(?2)?(?4a?3b+2c+d)

**Math**

(?5)?(3b?2a)?6(a+2b)

**math**

Thanks

**math**

callum wins £300 in a raffle. he gives 5% to charity. he saves 2/5 of the £300.he uses the rest of the money to buy clothes. work out how much of the money callum uses to buy clothes./ I tried this question before in a test we got given the test back and were told ...

**Chemistry**

Does every neutral helium atom in the universe have the same set of absorption lines as every other neutral helium atom (with the same atomic mass)?

**Chemistry**

oops sorry

**Chemistry**

Does every neutral helium atom in the universe have the same set of absorption lines as every other neutral helium atom (with the same atomic mass)?

**Math - Linear Approximation**

I have a follow-up question from a problem I posted earlier: Approximate sin(61?/360): So, sin(60?/360 + ?/360) = sin(?/6 + (?/360)) Now the equation for linear approximation is f(x+a)=f(a)+f'(a)(x-a). To get the right answer, that means plugging in the numbers like this: ...

**Math - Linear Approximation**

a) Find a linear approximation of y=sinx at x=pi/6 b) use part (a) to approximate sin(61pi/360) and sin(59pi/360) I just really have no idea how to approach this problem. I know the formula is y=f(a)+f'(a)(x-a). Does that mean it would be (sin(pi/6))+(0)((pi/6)-(sin(pi/6...

**Calculus**

A child is flying a kite. If the kite is 135 feet above the child's hand level and the wind is blowing it on a horizontal course at 7 feet per second, the child is paying out cord at ______ feet per second when 285 feet of cord are out. Assume that the cord remains ...

**Related Rates**

A street light is at the top of a 10.5 ft. tall pole. A man 5.4 ft tall walks away from the pole with a speed of 3.5 feet/sec along a straight path. How fast is the tip of his shadow moving when he is 47 feet from the pole?

**Math - Calculus**

Directions (or bearings) on Earth are measured in degrees, running from zero to 360 degrees, clockwise, starting with 0 degrees being due North. So due East for example, is 90 degrees, due South 180 degrees, and Northwest is 315 degrees. You are swinging a rock clockwise (...

**Math**

The figure at right shows a long rectangular strip of paper, one corner of which has been folded over to meet the opposite edge, thereby creating a 30-degree angle. Given that the width of the strip is 12 inches, find the length of the crease.

**Math**

A magician showed a magic trick where he picked one card from a standard deck. Determine what the probability is that the card will be a red color queen card ?

**Stephens **

Each of the letters in the word CALCULATOR are on separate cards, face down on the table. If you pick a card at random, what is the probability that it's letter it's letter will be C or L?

**Math - Calc/Algebra/Trig**

I'm trying to find all the points on the graph y=4/3cos^3x-cosx where the tangent line is horizontal. I took the derivative, which gave me: -4cos^2(x)sin(x)+sin(x) Now I need to solve it for x and I'm not sure how. Can you help?

**Math - Calculus**

The horizontal velocity is constant. (Ignore air resistance.) Recall from your study of trigonometry that if you release a rock at a speed v in a direction that makes an angle ? with the horizontal, then the initial vertical velocity vv and the horizontal velocity vh are given...

**Math**

You drop a rock into a deep well. You can't see the bottom of the well but you can hear the impact after T seconds. Suppose the speed of sound is c feet per second and the depth of the falling rock at time t is gt^2/2 feet. Compute the depth d of the well. Your answer will...

**Chemistry**

How much energy, in calories, does it take to convert 20.0 grams of solid water, at 0.0 degrees C, into liquid water, at 0.0 degrees C? (The enthalpy of fusion for H2O is 1.44 kcal/mol)

**Math**

WebWork = 28% Four exams = 6% each A final = 28% Labwork = 20% Suppose you obtain 100 percent credit on all WeBWorK assignments for this class. What is the minimum average percentage on the exams and labwork that will still get you an A in this class? (Remember an A is greater...

**math**

Lexie is painting her fence. each foot of the fence requires 3/5 of a gallon of paint. Her fence is 8 3/4 feet long.what is the total amount of paint,in gallons Lexie needs to paint her fence?

**Algebra **

In , is a right angle. Find the remaining sides and angles. Round your answers to the nearest tenth. Show your work. a = 3, c = 19

**Math**

A trail mix contains peanuts, chocolate pieces, and raisins. There are twice as many raisins as chocolate pieces. There are 20 less peanuts than raisins. In total, the mix contains 200 trail mix pieces. Write an equation in terms of r (the number of raisins) to represent this ...

**Grammar**

They look OK.

**Calculus**

Please help me. 1. Use the definition of the derivative to find f'(x), if f(x)=x^-2 2.Find the derivative of y=3t^5 - 5?t + 7/t

**Math**

8×5+8×1-2×6+6-2 add parentheses to get 22

**Physics**

Not sure where to begin with this question--any help appreciated! Two kids sitting on opposite sides of a small lake use sticks to beat the surface of the water at a frequency f=1.5 Hz. They notice that a standing wave pattern develops between the points where they are ...

**math**

Find an equation of the line having the given slope and containing the given point. m equals negative 7?, ?(5 ?,9?)

**Physics**

Not at all sure where to start with this problem. Any help would be appreciated! The siren of an ambulance has a frequency f=500 Hz. A pedestrian standing on a sidewalk listens to this siren as the ambulance passes by at a speed of 65 mph. The speed of sound in air is 330 m/s...

**Physics**

A pan flute is based on standing wave resonance in a tube that is open where the musician blows and closed at the bottom end with bee’s wax. (a) Describe the standing wave pattern of air displacement in such a tube when a tone is played. (b) Determine the length of the ...

**Physics**

Two kids sitting on opposite sides of a small lake use sticks to beat the surface of the water at a frequency f=1.5 Hz. They notice that a standing wave pattern develops between the points where they are disturbing the water surface. They count n=5 nodes over the L=10 m ...