# Posts by Christina

Total # Posts: 931

**biology**

if a rock had a mass of 9.00g, what is the density of the rock?

**calculus**

Find the limit. Use l'Hospital's Rule if appropriate. If there is a more elementary method, consider using it. lim x?? {(5x ? 4)/(5x + 3)}^5x + 1

**calculus**

Find the limit. Use l'Hospital's Rule if appropriate. If there is a more elementary method, consider using it. lim x?0 (e^x ? e^?x ? 2x)/(x ? sin(x))

**calculus**

Find dy/dx by implicit differentiation. arctan(2x^2y)=x+4xy^2

**calculus**

Find y'and y''. y=x^1/2 ln(x)

**Math**

what is 4+9 to the second power divided by 3x2-2

**Math**

use the digits 6 7 8 and 9 to make a problem with the largest product possible

**Math**

A sweater costs 15.99. If the sweater is on sale for 1/4 off its price, about how much would you save?

**math bus 105**

Calculate (a) interest and maturity value, (b) discount period, (c) bank discount, and (d) proceeds. Assume ordinary interest. (Round answers to nearest hundredths) Date of note Face value Length of note Interest rate Bank discount rate Date of discount Feb. 12 $80,000 150 ...

**Chemistry**

After mixing 1 g of 60% ee (+)-Kendomycin with 2 g of 80% ee (+)-Kendomycin, what is the ee of the final mixture? I know the answer is 73% ee, but I don't understand how to get to that answer!

**chemistry**

A compound contains 74,27%C;7,79%H;12,99%N. Determine the empirical formula. C=12;H=1;N=14;0=16.

**chemistry**

Calculate the percentage composition of sulphuric acid if the atomic masses are H=1u, S=32u and 0=16u

**maths /science**

A body calling from rest has a velocity of 25m/s at given instant. Calculate 1 the distance the body has fallen 2 the time taken

**maths/science**

A body falls from a position of rest at the top of a tall building and attains a velocity of 63.7m/s just before striking the ground. Calculate the time for the body to fall from the top of the building to the ground

**maths**

Calculate the velocity of a stone7 seconds after falling from rest of the edge of a high cliff

**Clc**

5 more than the product of -2 and the number

**Math**

Alice can complete a certain job in 5 hours she had been working on the job for two hours when a friend came along. And helped her finish together they completed the job in 1 hr how long would it take alices friend to complete a job on her own. I have 1 fifth plus 1 over1 ...

**Math help**

Use what's called the percent change formula: % Change=New amount-old amount/old amount and multiply the answer by 100 to get it in terms of percentage. For example: 14-9=5 5/14 (14 because that was its initial price prior to it decreasing) =0.3571. We want our answer in ...

**Life Orientation**

Restorative justice is a new concept in the south african legal landscape. Explain briefly what its intentions are in the process of human rights violations

**lifeorientation**

Xenophobia

**life orientation**

Education -you have the right to basic education example work hard, attend school regularly

**physics**

Can the value of equilibrant be equal to zero? If yes, why?

**Art**

No name is 100% right! I took the test and got 100%! Thank you no name!

**chemistry**

Suppose that the microwave radiation has a wavelength of 12 cm . How many photons are required to heat 255 mL of coffee from 25.0 ∘C to 62.0 ∘C? Assume that the coffee has the same density, 0.997 g/mL , and specific heat capacity, 4.184 J/(g⋅K) , as water ...

**Math**

C 9P4 = C There are 9 slots, in which 4 parts can be placed in. Order also matters for each part/role. Therefore, 9P4

**Geometry**

1. D. BOA 2. B. Right (I think) 3. A. 105 4. B. Sometimes Sorry I didn't answer sooner I just found this question.

**stats**

Out of 16 actors, there are 10 female roles. Out of 9 actors, there are 5 male roles. Therefore, 16P10 * 9P5 = Answer

**Calculus- Damon, Steve, Reiny**

I forgot to mention that I am trying to find sigma squared.. given that the mean is r and p(x)= (1/r)(e^(-x/r)) on the interval [0,infinity), where r>0.. note: sigma squared= integral sign (-inf, inf) (x-M)^2 p(x) dx i got (r^2 - 2r)^(1/2) for sigma, but my answer is wrong...

**Calculus- NEED HELP!!!**

I got r^2 - 2r.. and it is wrong.... please help....

**Calculus**

I tried to integrate this: intergral sign with an interval from -inifinity to + infinity function: (x-r)^2 (1/r) (e^(-x/r)) with respect to dx..... I know that Steve set up the u-substitution but I seem to never arrive at an answer... It seems like I keep integrating and ...

**Calculus**

How do you integrate (x-r)^2 (1/r) (e^(-x/r)) from the interval negative infinity to positive infinity?

**maths**

a bag contains three labelled A,R,C and a box contains 4 cards 1,2,3,5. if cards are picked from the bag and from the box, find the probability of picking on A and a prime number

**Calculus**

Calculate μ and σ, where σ is the standard deviation, defined by the following. σ^2 = integral between (−∞,∞) (x-μ)^2 p(x) dx The smaller the value of σ the more tightly clustered are the values of the random variable X about the...

**Chemistry**

Why does carbonate have a -2 charge and not -1? Why does phosphate have a -3 charge and not -2 or -1? Why does nitrate have a -1 charge and not -2 or -3? My answer: Based on the Lewis structure, these ions need a certain number of electrons in order to be stable...the octet ...

**Chemistry**

Rank the following in order of increasing bond polarity: H-F, H-Br, F-F, Na-Cl. Is it this....? F-F, H-Br, H-F, Na-Cl

**Chemistry**

Why does carbonate have a -2 charge and not -1? Why does phosphate have a -3 charge and not -2 or -1? Why does nitrate have a -1 charge and not -2 or -3? My answer: Based on the Lewis structure, these ions need a certain number of electrons in order to be stable...the octet ...

**math**

how much flour will be needed to make 3 pies if using 1 3/4 cups of flour? i need two ways of solving this question please

**Chemistry**

My final temperature was higher than my initial temperature, and my graph shows that the temperature icreases and then decreases. I thought that would make it exothermic, but don't exothermic reactions give off heat? If someone could clear this up, I would really ...

**Chemistry**

How can I tell from a graph of temperature vs. time if a reaction is endothermic or exothermic?

**8th Grade Science**

How do adaptations enable organisms to reduce competion for food and other resources PLEASE ANSWER BY 4 (50 MINS)

**Algebra**

Find the linear function with the following properties: f(0)=1 and the slope of f equals -3/2 THANK YOU

**la history**

Thanks Dick H. your answers are correct. =)

**la history**

answer them. duh! lmao xD

**Algebra**

The back of Tom's property is a creek. Tom would like to enclose a rectangular area, using the creek as one side and fencing for the other three sides, to create a corral. If there is 100 feet of fencing available, what is the maximum possible area of the corral? ? square ...

**Math 71x**

One cell phone plan allows 200 text messages per month for $20 after which text messages cost $0.04 each. Another cell plan allows 400 text essages per month for $30 each. What would be the minimum text messages that would justify the more expensive plan

**Stats**

estimate the probability that a patient has health insurance, if 59% of Americans have private insurance and 25% have government insurance. Estimate the probability that it is private insurance Is this P(A and B) = P(A) x P(B)

**Math**

Bob was riding his dune buggy. Part of the time he was riding at 10 mph and the remainder of the time at 14 mph. The total distance traveled was 68 miles and it took him 5 hours. How much time was spent traveling at 10 mph?

**Physical Science**

how much energy must be removed from 1 L of water at 25 C and turn it to ice at -10 C?

**Chemistry**

When 24.0 cal of heat is added to 18.5 g of aluminum at 19.0 ∘C, what is the final temperature of the aluminum?

**science**

a baby pushes a toy across the floor with a force of 5 newtons inertia balanced force unbalanced force velocity

**Statistics**

A random sample of 100 cable TV movies contained an average of 3.38 acts of physical violence per program. At the 99% level what is your estimate of the population value? mean = 3.38 s = 0.30 N = 100

**Bio**

Why do doctors recommend that people get a flu shot each new flu season? The vaccine wears out over time. The body eliminates the vaccine. The flu virus changes every year. The flu virus becomes immune to the vaccine.

**Science**

What do B cells do?

**Science**

n(No/N) = kt No = 100 N = 85 t = 5 days solve for k Then ln(No/N) = kt No = 100 N = ? solve for this amount remaining. k = from above t = 25 days N is what is left. (N/100)*100 = % left

**Biology**

OMG I did this one before!

**programming**

Using python write a program that does the following: •Create the logic for a program whose main() method prompts a user for 1000 numbers and stores them in a list. •Pass the array to a method that reverses the order of the numbers. •In the main program, display...

**Programming logic and design**

Using python write a program that does the following: •Create the logic for a program that calculates and displays the amount of money you would have if you invested $3000 at 2.65 percent interest for one year. •Create a separate method to do the calculation and ...

**Math**

Ms. Sue you may be a math teacher but wording is important here. The correct answer should be 30%. It didn't say what percentage of total students chose walking, it said what percentage of boys chose walking. There are 10 boys, 3 of whom chose walking. Therefore, the ...

**Math**

Wow Ms.Sue who ever you are I keep seeing you on this website.

**physics**

dahnay carried a box (5,4)m.the box had a mass of 5kg.dahnay says that over 300J of work was done on the box . is dahnay correct?explain the answer.

**English**

What is the difference between the denotative and connotative meaning of a word?

**Ss help 8th**

Compare and contrast the experiences of the Creeks and Cherokees in Georgia following the War of 1812

**SS ANYONE HELP?**

you know any links i can find my answers? anything. i need help on this.

**SS ANYONE HELP?**

Describe significant events in the social and economic reconstruction of the South. Why are these events significant?

**PLEASE HELP CHECK? MS. SUE ANYONE?**

How is this so far? and what else should i add, i need two pages and i have only one done, due today. help? I'm doing like a journalist. I Josephine A. Walker was a slave for Harry Richardson. Every morning I had to serve him, I had to be up by 4am and was unable to go to ...

**SS**

How is this so far? and what else should i add, i need two pages and i have only one done, due today. help? I Josephine A. Walker was a slave for Harry Richardson. Every morning I had to serve him, I had to be up by 4am and was unable to go to bed till 12am midnight. I had to ...

**geography**

What are examples of human adaptation to the environment?

**Geography**

What role did the waterways of Europe play in the development of it's economy?

**Geography**

How are the landforms of Europe both an advantages and a disadvantage to life in Europe?

**Physics**

You are going diving in a pool of fresh water. Your body can only take a total pressure on it of 2.0 atmospheres. How deep can you dive before your body can no longer take the pressure?

**physics**

A toy boat has a volume of 0.0005m^3. It has a mass of 450 grams. How much of the boat is under fresh water?

**Physics**

A hot air balloon of radius 12 meters has been heated so that the air inside has a density of 1.05 kg/m^3. What can the total load of the balloon be (mass of balloon itself plus cargo) if you need the balloon to accelerate into the air with an acceleration of 4 m/s^2?

**algebra**

You deposit $3000 in an account earning 7% interest compounded continuously. The amount of money in the account after years is given by A(t)=3000 e^(0.07 t) . How much will you have in the account in 5 years? $ Round your answer to 2 decimal places. How long will it be until ...

**science**

A swimming pool measures 10m by 7m by 2m calculate the full force exerted by the water against the bottom. What is the pressure at the bottom due to the water?

**Accounting**

computer equipment beginning balance is 20,000 working on the adjusted general journal and the scenario is the computer has a 4 year life with no salvage value not sure how to log this

**science**

Bill kicks a rock off the top of his apt building it strikes a window across the street 18m away the acceleration of gravity is 9.8m/s if the window is 25m below the position where bill contacted the rock how long was it ini the air

**Chemistry 11**

Thank you guys so much for helping me! I see my steps were really unnecessary.

**Chemistry 11**

Find the percent composition of a compound containing sodium and chlorine if 24.34g of the compound contains 13.45g of sodium. My work: Molar mass of NaCl: MNa +MCl = 22.99 g/mol + 35.45 g/mol = 58.44 g/mol Percent composition of Na: 22.99 g/mol / 58.44 g/mol x 100 = 39.34% Na...

**Accounting**

34000

**science-gen chem**

if 0.969 g of CaCl2 is mixed with 1.111 g of KlO3 how many grams of solid Ca(IO3)2 can theoretically be made? CaCl2(aq) + 2KlO3(aq) ===> 2Kcl(aq) + Ca(lO3)2 (s)

**math**

If the sun is aplroximantely 1.5×10^(11) meters from Earth, what is the approximate distance from Earth to Mars.

**College Chemistry**

Suppose there are two known compounds containing the generic elements X and Y. You have a 1.00-g sample of each compound. One sample contains 0.29 g of X and the other contains 0.38 g of X. Identify plausible sets of formulas for these two compounds. Check all that apply. XY ...

**Math**

The Mills Lunch Shop prepares fresh take-out entrees each day. On Tuesday, 40 baked chicken dinners were prepared at a cost of $3.20 each. A 20% spoilage rate is anticipated. Mills Lunch Shop sells the dinners at an 80% markup based on cost. They decided to offer a $1.00-off ...

**Geography**

Which geographic feature marks the last natural obstacle for Georgia’s rivers on their way to the Atlantic Ocean? (1 point) the Floridian Aquifer the Valley and Ridge region the Fall Line *** (MY ANSWER) the Marshes of Glynn AM I RIGHT?

**Tourism**

I don't know which career i must do with the subjects i chose

**Geography**

1. Is all of the above

**Geography**

1.Encouraging crops with longer growing seasons 2.both the first and third answer choices 3.the Fall Line 4.aquifer Am i right Ms. Sue?

**Geography**

Which of the following are impacts that the temperate climate has had on Georgia’s development? (1 point) encouraging crops with longer growing seasons drawing immigrants from other locations encouraging tourism all of the above 3. What impacts have precipitation and ...

**Geography**

Which of the following most accurately describes the difference between climate and weather? (1 point) Climate refers to long-terms conditions; weather refers to daily conditions. Climate refers to severe weather events; weather refers to precipitation. Climate refers to land ...

**Science**

Inductive reasoning is right(: A+

**Science**

In the early 1900s, Alfred Wegener noticed that some of the Earth's continents looked like they might fit together like a jigsaw puzzle. He also observed that the continents that looked like they fit together had similar plants, animals, and rock formations. From this ...

**physics**

speed=30km/h time=0.5hrs distance=s*t =15km speed=25km/h time=1hrs distance=s*t =25km speed=40km/h time=2hrs distance=s*t =80km average speed= total distance/total time taken = (15+25+80)/(1+2+0.5) = 120/3.5 = 34.28km/h.

**physics**

Two mirrors are placed at a 90° angle to each other. A light ray strikes one mirror 0.730 m from the intersection of the mirrors with an incident angle of 36.5°. The ray then travels a distance d before reflecting from the second mirror. (a) What is the distance d?

**general science**

if an object is thrown 60 m into the air and it takes the object 6 s to get there, what's the average speed of the object? (A) 20m/s (B) 360 m/s (C) 100 m/s (D) 10 m/s

**Chemistry**

Write the class/family of the following compounds and the functional group in each compound. a. 3-methylcyclohexene b. Cis-3-octene c. 4-methyl-2-heptanone d. 3-bromobenzaldehyde e. 3-bromo-5-chlorotoluene f. 3-chlorophenol g. 6-methyl-2-heptyne Please help!

**Stats**

Find the P-value for a left tailed hypothesis test with a test statistic of z= -1.77. Decide wether to reject the null if the level of significance is alpha= 0.05. Please help I've tried everything and I can't figure out how to get the right answer..

**Hanus**

points Q (10,8) and R (24,10) are the endpoints of a diameter of a circle centered at P. Line l is tangent to the circle at S (12,14). What is the y-intercept of line l?

**Statistics**

In a survey of 621 males ages 18-64 , 396 say they have gone to the dentist in the past year. Construct 90% and 95% confidence intervals for the proportion. Interpret the results and compare the widths of the confidence intervals. Please show step by step. Thank you!

**Physics**

You are given a four-wheeled cart of mass 11 kg, where the distance between a wheel and its nearest neighbors is 2.1 m. Suppose we load this cart with a crate of mass 109 kg, where the crate's center of mass is located in the back-middle of the cart, 0.525 m from its ...