# Christina

Newest questions posted by Christina-
## Science

In a new system of unit called star unit 1*kg=10kg,1m*=1km,1s*=1min. Convert 1J of energy in new system of unit. -
## math

Maude uses 3/4 of her allowance to get a massage for 3/5 of an hour. What fraxction of her allowance would she need to get a massage for a full hour? -
## Algebra

I need help solving 4 equations step by step. Please help. 5 1. --- (t) = -9 13 X+2 2. 6 = ----- 3 W 3. 13 + --- = -18 7 4. 17 = -13 - 8x -
## Chemistry

You have a solution of 0.500 M NaCl. If you add an equal amount of water to this solution, doubling the volume, what is the concentration of this solution? -
## Chemistry

The percent composition by mass of an unknown compound with a molecular mass of 60.052 amu is 40.002% C, 6.7135% H, and 53.284% O. Determine the compound's empirical and molecular formulas. -
## English

If I understood correctly, does the statement below mean that I must e-mail on Friday, November 5, 2017 but no later than 12 pm to confirm the interview or does it mean that I can e-mail earlier by the deadline, which is 12 pm on Friday, November 5, 2017? -
## algrebra

find g^4(x) and the domain and range of g(x) and g^4(x) 1. g(x) = 9 - x^2, x< 0 2. g(x) = (x - 1)^2 +1, x -
## algebra

solve the following equation x^2+16=0 -
## 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 -
## 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 -
## physics

Can the value of equilibrant be equal to zero? If yes, why? -
## 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 -
## 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 -
## 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 -
## 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 mean μ. p(x) -
## 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 -
## 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 -
## 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

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 -
## 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 -
## 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? -
## 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 -
## 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 -
## 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?

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 -
## 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 -
## 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 -
## 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 -
## 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

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 -
## 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 -
## 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 -
## 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? -
## 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 -
## 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. -
## 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 -
## 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 -
## 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 -
## 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. -
## 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 -
## Physics

Suppose we take a 1 m long uniform bar and support it at the 27 cm mark. Hanging a 0.31 kg mass on the short end of the beam results in the system being in balance. Find the mass of the beam. -
## Spanish2

Está prohibido fumar. (Write advertisements or signs for the situations described. Use impersonal constructions with se.) -
## pre-calculus

Find the real and imaginary zeros for the following polynomial function. T(b)= 147b^3-35b^2-19b+3 -
## RE: Physics

If an incline has a difference in height from one end to the other of 17.8 cm and has a length along the incline of 1.19 m, what is the angle that the incline makes with the horizontal reference surface? Physics - Damon, Saturday, February 15, 2014 at -
## Physics

If an incline has a difference in height from one end to the other of 17.8 cm and has a length along the incline of 1.19 m, what is the angle that the incline makes with the horizontal reference surface? -
## Chem

what mass of hydrogen was in an unknown compound containing only c, h, and o if 2.65kg H2O was produced by combustion analysis -
## physics

In the circuit shown, find the voltage Vx (in Volts) if V = 17.0 Volts, R1 = 13.0 k ohms, R2 = 4.0 k ohms, R3 = 13.0 k ohms and R4 = 21.0 k ohms. Answer is -6.5 I don't understand how they got it, can someone please explain it with steps? Thanks tinypic. c -
## Physics

In the circuit shown, find the voltage Vx (in Volts) if V = 17.0 Volts, R1 = 13.0 k ohms, R2 = 4.0 k ohms, R3 = 13.0 k ohms and R4 = 21.0 k ohms. Answer is -6.5 I don't understand how they got it, can someone please explain it with steps? Thanks tinypic. c -
## Physics

If the resistances R1= 16. ohms, R2 = 38. ohms, and R3 = 18. ohms, and the voltage V = 6.0 volts, what is the current ix (in Amperes) in the circuit. tinypic .cm /r / nfr48k/ 8 The correct answer is .1443 but I want to know how they got that. Thanks. -
## science

You measure the dimensions of a rectangular block of aluminum to determine its volume. It has the following dimensions. length = 10.27 cm; width = 4.92 cm; height = 1.53 cm Assuming that each of these measurements is accurate to the nearest 0.01 cm, find -
## Science

The sensitivity of a measuring instrument is the value of the smallest quantity that can be read or estimated with it. What is the smallest part of a centimeter that can be read with the following? (a) a meterstick with markings at each millimeter I tried -
## Physics

A test rocket is launched by accelerating it along a 200.0-m incline at 1.25m/s2 starting from rest at point A (the figure (Figure 1) .) The incline rises at 35.0 ∘ above the horizontal, and at the instant the rocket leaves it, its engines turn off and -
## Physics

A test rocket is launched by accelerating it along a 200.0-m incline at 1.25m/s2 starting from rest at point A (the figure (Figure 1) .) The incline rises at 35.0 ∘ above the horizontal, and at the instant the rocket leaves it, its engines turn off and -
## Calculus

Consider the solid obtained by rotating the region bounded by the following curves about the line x=1. y=x,y=0,x=4,x=6 Find the volume So it would be pi (integral from 3 to 6) of ((1-y)^2 -(1-0)^2) right? so then you integrate it and get pi(Y^3/3-y^2) from -
## Physics

A 0.5 kg wooden block is dropped from a height of 15 m. At what height must a 5g bullet be traveling upward strike the block in order to momentarily stop its fall? Assume that the time required for the bullet to come to rest in the block in negligibly -
## Physics

An explorer in the dense jungles of equatorial Africa leaves his hut. He takes 41 steps at an angle 45∘ north of east, then 81 steps at an angle 60∘ north of west, then 49 steps due south. Assume his steps all have equal length. Save him from becoming -
## science/math

A car traveling at the speed of 30.0 m/sec encounters an emergency and comes to a complete stop. how much time will it take for the car to stop if its rate of deceleration is -4.0 m/sec