Wednesday

April 16, 2014

April 16, 2014

Total # Posts: 120

**Chemistry**

Balance the following redox (oxidation-reduction) reaction under basic conditions. (Include states-of-matter under the given conditions in your answer. Use the lowest possible whole number coefficients.) CrO42−(aq) + S2O32−(aq) → Cr3+(aq) + SO42−(aq)

**Physics**

A single mass (m1 = 3.2 kg) hangs from a spring in a motionless elevator. The spring constant is k = 253 N/m. 1) What is the distance the spring is stretched from its unstretched length? This first answer is equal to 12.4 cm but I am having trouble on the second question... 2)...

**Physics**

You are on an airplane traveling 30° south of due west at 130 m/s with respect to the air. The air is moving with a speed 30 m/s with respect to the ground due north. One question.. 2) What is the heading of the plane with respect to the ground? (Let 0° represent due n...

**math 6th grade**

the bridge span is 360 meters long. the bridge is 30 meters shorter than the main span. write and solve an equation to the the length of the main span

**math**

i need the equation

**math**

the length of the blue ribbon is two-thirds of the length of the red ribbon. writh an equation to find the length r of the red ribbon

**Physics**

A red ball is thrown down with an initial speed of 1.2 m/s from a height of 25 meters above the ground. Then, 0.6 seconds after the red ball is thrown, a blue ball is thrown upward with an initial speed of 22.9 m/s, from a height of 0.8 meters above the ground. The force of gr...

**Physics**

Hey bobpursley! ITS 3.09!! YAYY thanks lot!

** Physics**

A blue ball is thrown upward with an initial speed of 19.6 m/s, from a height of 0.5 meters above the ground. 2.4 seconds after the blue ball is thrown, a red ball is thrown down with an initial speed of 7.9 m/s from a height of 22.1 meters above the ground. The force of gravi...

**math **

cot^2(x)-1/1+cot^2(x)

**Trigonometry **

(1/(cscx+1))-(1/(cscx-1))

**Trigonometry **

simplify: tanx/secx+1

**Trig**

sin^2(34)+sin^2(48)+sin^2(56)+sin^2(42)

**Trig**

sqrt(100+(10cotx)^2)

**math 2nd grade**

24-16=8

**Statistics**

A credit manager has chosen a sample of size 2,164 to estimate the mean balance of credit accounts to within $0.50. A pilot study of 50 accounts had a mean of $1,219 and a variance of 100. The level of confidence of the interval is: 90% 95% 98% 99%

**Hypothesis Test**

that isn't one of the choices :/

**Statistics**

Thank you so much !

**Statistics**

$9,531 to $11,269 $9,347 to $11,453 $10,028 to $10,772 $9,414 to $11,386 Are my multiple choice

**Statistics**

That's what I originally did but it's not one of the correct answers

**Statistics**

A random sample of 50 students chosen from an elementary school with 400 students was found to have a mean allowance of $26 per week with a standard deviation of $8. Obtain a 98% confidence interval for the total amount of allowance money given to students in this school per w...

**Stats**

A company with two plants producing the same product, but with two slightly different manufacturing processes, conducted a sample study at each of the two plants with the following results: The sample statistics from the first group are: n = 40, x-bar = 18, s = 4.2. The sample...

**Physics**

A jetliner, travelling northward, is landing with a speed of 79 m/s. Once the jet touches down, it has 710 m of runway in which to reduce its speed to 7.4 m/s. Compute the the average accelaration (magnitude and direction) of the plane during landing.

**Instructional materials, their preparation and use**

Which of the following would you use to sort through slides for a slide or injection?

**stats**

Usin7) An employer polled its employers to see if they agree with the proposed new store hours and whether or not their present shift made a difference in their answers. The customers answered 1 for agree, 2 for don't know, and 3 for disagree. Nine first shift employees an...

**Statistics**

For questions 1-5, write the null and alternative hypothesis. 1. Does the water temperature have an effect on the number of people in the pool? 2. Does the weather have an effect on the number of people at the beach? 3. A fitness center is running a discounted membership fee. ...

**Statistics**

1. A study of 40 people found that they could do on the average15 pull ups with a standard deviation of .6. Find the 99% confidence interval for the mean of the population. 2. A study of 50 pizza delivery workers found that they could make 6 deliveries per hour with a standard...

**statistics**

2. Why is it important to know the mean and standard deviation for a data set when applying the empirical rule? 3. If we are focused on 68% of the normal distribution, what percentage of the distribution is left in the upper tail only? 4. What value separates the 50% of the di...

**statistics**

A study found that citizens spend on average $1950 per year on groceries with a standard deviation of $100. Assume that the variable is normally distributed. 5. Identify the population mean. 6. Identify the population standard deviation. 7. Find the probability that a sample o...

**statistics**

A specific study found that the average number of doctor visits per year for people over 55 is 8 with a standard deviation of 2. Assume that the variable is normally distributed. 1. Identify the population mean. 2. Identify the population standard deviation. 3. Suppose a rando...

**Teaching techniques**

Which learning technique is frequently used in the expository model of teaching?

**Calculus**

Find the second derivative of the function f(x)= t^2e^(-2t)

**Calculus**

Write the expression as the logarithm of a single quantity. ln 2 + 1/2 ln(x +1)-2 ln(1+ x^(1/2))

**Calculus**

Determine the function is concave upward and where it is concave downward f(x)= x / (x+1)

**Calculus**

Find the absolute maximum value and the absolute minimum value, f(x)= (x +1 )/ (x-1) on [2, 4]

**Calculus**

Find the absolute maximum value and the absolute minimum value, g(x)=1/8 x^2 - 4 x^(1/2) on [0, 9]

**College Math**

I need help solving these problems by using the substitution problem 2x-3y=16 5x+2y=21

**Chemistry**

Calculate the pH of the 0.20 M NH3/0.25 M NH4Cl buffer. I calculated the pH to be 9.15 What is the pH of the buffer after the addition of 10.0 mL of 0.10 M HCl to 72.5 mL of the buffer?

**Calculus**

Find relative maxima and minima of g(x)= 2x^2+ 4000/x +10

**calculus**

Let f(x)=ax^3+6x^2+bx+4. Determine the constants a and b so that f has a relative minimu at x=-1 and a relative maximumat x=2.

**6th math**

a factory can produce 45 containers of yogurt in t minutes, 950 grams of fruit are used for every 25 containers of yogurt b) find in terms of t the time taken by the factory to produce 100 containers of yogurt c) if t=6 find the amount of fruit used in producing containers of ...

**physical science**

You are at a concert and you are located 91.2-m from the speakers. The frequency belting from the speakers are 291-Hz, if it takes 0.230-sec for the sound to reach your location what is the sounds wavelength?

**physical science**

You are at a concert and you are located 95.9-m from the speakers. The frequency belting from the speakers are 257-Hz, if it takes 0.503-sec for the sound to reach your location what is the sounds wavelength?

**physical science**

You are at a concert and you are located 97.5-m from the speakers. The frequency belting from the speakers are 216-Hz, if it takes 0.181-sec for the sound to reach your location what is the speed of sound in this facility?

**Math**

If Bob hikes 5/8 of a mile in 1/3 of an hour. How fast is going in miles per hour?

**Biology**

what two mutations cause a shift or after the sequence after the mutation?

**Biology**

do mutations occur in DNA or RNA? Explain

**Biology**

what is the difference between a gene mutation and a chromosomal mutation?

**physics**

)A block with mass m = 11.3 kg slides down an inclined plane of slope angle 43.4 ° with a constant velocity. It is then projected up the same plane with an initial speed 1.45 m/s. How far up the incline will the block move before coming to rest?

**physics**

)A block with mass m = 11.3 kg slides down an inclined plane of slope angle 43.4 ° with a constant velocity. It is then projected up the same plane with an initial speed 1.45 m/s. How far up the incline will the block move before coming to rest?

**English**

On an invitation, it says "Come celebrate at my pad!" and has a picture of a lilly pad on it. Is this an example of a pun?

**math**

dave has a rabbit, a ferret,a gerbil and a turtle. He feeds them in a different order each day. In how many different orders can dave feed his pets. Make an organized list to solve each problem. Write each answer in a complete sentence show work please

**math**

the end points of a line segment are A (-7, -1) and B (5,5) determine the equation of right bisector of AB show that the origin 0,0 lies on the right bisector of AB

**Math**

How do you find the high and low estimate for 29 x 73 and 615 X 25?

**abnormal child psychology**

someone who focuses narrowly on negative events for long periods of a time has. A-negative attitude. B-depressive manner. C-negative focus. D-depressive ruminative style.

**trig**

verify the identity algebraically- (5-5 cos x)(5+5 cos x)=25 (sin^x)

**Chemistry University One**

Is it possible for a calorimeter to have a high specific heat capacity, such as 2780J? I don't know if that is a reasonable answer.

**Physics**

fbzffb

**trig**

A force of 50 pounds acts on an object at an angle of 45°. A second force of 75 pounds acts on the object at an angle of -30°. Find the direction and magnitude of the resultant force.

**geometry**

For problems 7 and 8, find the magnitude and direction angle of the given vector. 7. <3, 4> A magnitude: 5; direction angle: 53.13° B magnitude: √ 5; direction angle: 53.13° C magnitude: √5; direction angle: 3.40° D magnitude: √5; direction ...

**geometry**

1. Initial point: (0, 0); Terminal point: (3, -4) A Lesson 13 B Lesson 13 C Lesson 13 D Lesson 13 E Lesson 13 F Lesson 13 2. Initial point: (3, 5); Terminal point: (-2, -1) A Lesson 13 B Lesson 13 C Lesson 13 D Lesson 13 E Lesson 13 F Lesson 13 In problems 3 and 4, let u = Les...

**geometry**

In problems 1 and 2, the initial point and the terminal point of a vector are given. Write the vector in component form. 1. Initial point: (0, 0); Terminal point: (3, -4) A Lesson 13 B Lesson 13 C Lesson 13 D Lesson 13 E Lesson 13 F Lesson 13 2. Initial point: (3, 5); Terminal...

**geometry**

Two forces are pushing on an object, one at 12 lbs of Force and one at 5.66 lbs of Force. The angle between them is 35° (each is 72.5 from horizontal, such that the forces make a v with the object in the center). 17. What is the total Force on the object? 18. What is the s...

**biology**

birds

**geometry**

Two forces are pushing on an object, one at 12 lbs of Force and one at 5.66 lbs of Force. The angle between them is 35° (each is 72.5 from horizontal, such that the forces make a v with the object in the center). 17. What is the total Force on the object? 18. What is the s...

**geometry**

16. Vector A has a magnitude of 3 in the leftward direction and B has a magnitude of 5 in the rightward direction. What is the value of 2A – B? You can also answer other types of problems using vectors. Try this one: Two forces are pushing on an object, one at 12 lbs of F...

**geometry**

16. Vector A has a magnitude of 3 in the leftward direction and B has a magnitude of 5 in the rightward direction. What is the value of 2A – B? You can also answer other types of problems using vectors. Try this one: Two forces are pushing on an object, one at 12 lbs of F...

**geometry**

A plane is heading west at 200 mph. The wind is blowing S30°W at 25 mph. 1. What is the ground speed of the plane? 2. When you solve the triangle, what is the smallest angle? 3. What is the largest angle of the triangle? 4. What is the remaining angle? 5. What is the beari...

**physics**

Alright. Thanks for the help!

**physics**

Oh okay. But then what kind of kinematics equation would you use?

**physics**

a gun fires a shell with a speed of 315m/s. Neglecting the effects of air resistance, calculate the maximum range of this gun

**Dimensional Analysis**

Convert 1.60ml into microliters

**programming**

2. A public light utitlity company bills a unit of electricity usage in KWH. In its new billing policy, domestic usage, Rate 15, will have a monthly rate of $ 12.20 per unit for the first 100 KWH; $ 18.25 per unit for the next 700 KWH and $ 42.10 per unit for the each addition...

**calculus**

F(x)=square root(27x-x^4)

**physics**

if a plane is flying at a speed so that the apex half-angle of its shock wave is 30 degrees, what is the speed if the speed of sound is 320 m/s?

**Algebra**

What is the remainder when 13 to the 51st power is divided by 5?

**chemistry**

A heater caused the temperature of a 550 g Aluminum block to change from 22 degrees C to 145 degrees C. How many calories were required to heat the metal block?

**chemistry**

how much calcium oxide is recovered when 250 g calcium hydroxide are heated given the following reaction? Ca(OH)2 arrow CaO + H2O

**chemistry**

caffeine has a half-life of 4.6 hours in the human body.. How long would it take 125 milligrams tritium to decay to 22 milligrams?

**Physics**

With what minimum speed must you toss a 130 g ball straight up to hit the 12 m-high roof of the gymnasium if you release the ball 1.3 m above the ground? I already figured out the minimum speed, 14m/s I'm confused on the next part With what speed does the ball hit the grou...

**allgebra ll**

solve 3x=8=3x2 by completing the square

**English**

I got 88.2% also, but the answers were arranged and worded different.. For a few of them tho like 4 and 6 I used my own answers.

**chemistry**

A sample of a hydrate of CuSO4 with a mass of 250 grams was heated until all the water was removed. The sample was then weighed and found to have a mass of 160 grams. What is the formula for the hydrate? CuSO4 * 10 H2O CuSO4 * 7 H2O CuSO4 * 5 H2O CuSO4 * 2 H2O CuSO4 * H2O

**spanish3**

Translate: Sara always used to lose her keys. Is it? Sara siempre se le perdia los papeles.

**Chemistry**

for the same question: what is the rate of decomposition (in mol/L*hr) when C2H6= 0.00422 M?

**chemistry**

An analysis of an unknown compound found it contained 40 g potassium, 52 g chromium and 56 g of oxygen. a) What is the empirical formula for this compound? Show the work you did to determine the formula. b) What type of compound is it, ionic, covalent or a combination of both?...

**Math (Algebra)**

can someone help me

**writing **

what are two characteristics of orientalism

**writing**

since 911, what are some changes the united states has made to policy concerning arabs and muslims treatment

**writing**

what is the difference between arab and muslims

**11th grade Physics**

Trevor has a mass of 58.0 kg. What is his weight?

**Chemistry**

Which of the following reactions needs to be reversed to solve for the Heat of Neutralization between Hydrochloric Acid and Ammonia? Acetic Acid + Sodium Hydroxide Hydrochloric Acid + Sodium Hydroxide Acetic Acid + Ammonia

**Supervision**

Ringworm is

**4gr math**

410,411,413

**Math**

Determine the future value of an annuity due into which quarterly deposits of $450 are made for nine years if the annuity pays 10% compounded quarterly.

**Math**

Use place value to solve. There are 75 children in the concert. there are 8 boxes of song books. there are 10 books in each box.Is there a book for each child in the concert? How do you know?

**math**

A bookcase has 43 books. there are 34 students in the class. Are there enough books for the students? how do you know? use place value to solve

**psycology**

which of the following statements regarding sex hormones is true?

**5th grade**

thank you :) i get it now.

**5th grade**

ok I kind of understand. But how did you get from 8/100 to 2/25 you are reducing right/ but how?