Sunday

January 25, 2015

January 25, 2015

Total # Posts: 134

**science**

Some hypothetical metal has the simple cubic crystal structure. If its atomic weight is 70.4 g/mol and the atomic radius is 0.126 nm, compute its density in g/cc.
*January 22, 2015*

**math**

Jackson have a piece of wood that is 6 feet long. He is cutting it into pieces that are 1/3 of a foot. How many pieces of wood will he have after he cuts it?
*January 7, 2015*

**Math**

sin A = 1/2 A = 30 degrees sin is opposite over hypotenuse thus, BC/AC BC = 8 (given) thus 1/2 = 8/AC AC = 16 cos A is cos 30degrees so cos A = (sqrt(3)) / 2 cos is always adjacent over hypotenuse thus, AB/AC because AC = 16 sqrt3 /2 = AB/16 AB = 8 sqrt3
*November 12, 2014*

**Differential Equations**

(a) Let S be the set of solutions y(t) to the differential equation dy/dt = -y for t> 0. With addition and scalar multiplication of elements defined in the usual way, is S a vector space? (b)Let T be the set of solution y(t) to the differential equation dy/dt = 1 - y for t...
*October 13, 2014*

**math**

Jenny wanted to solve the quadratic equation x2 - 11x +18 = 0 by factoring. Which of the following equations would lead her to solve the given equation?
*August 30, 2014*

**Math DE**

Find the general solution of the differential equation dy/dx-4y= -5y^2
*August 3, 2014*

**geography**

1. B 2. D 3. D 4. D 5. C 6. A 7. C 8. D 9. C
*May 22, 2014*

**Math**

Expand (1+y+ky^2)^8 until y^3
*May 10, 2014*

**physics**

okay, I got it thanks !
*April 25, 2014*

**physics**

6.67e-11
*April 25, 2014*

**Damon**

the mass of the moon is M=7.35e22 and the radius= 1.738 e6 I used the formula 1/2m(2/5vi)^2 - GMm/h+R= 1/2vi^2-GMm/R Where little m cancels out and solved for h. But my answer and the answer you just gave me was marked wrong. So you have any other suggestions?
*April 25, 2014*

**physics**

A projectile is launched vertically from the surface of the Moon with an initial speed of 1210 m/s. At what altitude is the projectile's speed two-fifths its initial value?
*April 25, 2014*

**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)
*April 14, 2014*

**physics**

Same here Heather, same here.
*April 3, 2014*

**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)...
*February 21, 2014*

**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 ...
*February 15, 2014*

**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
*February 3, 2014*

**math**

i need the equation
*February 3, 2014*

**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
*February 3, 2014*

**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 ...
*February 2, 2014*

**Physics**

Hey bobpursley! ITS 3.09!! YAYY thanks lot!
*February 2, 2014*

** 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 ...
*February 2, 2014*

**math **

cot^2(x)-1/1+cot^2(x)
*November 20, 2013*

**Trigonometry **

(1/(cscx+1))-(1/(cscx-1))
*November 20, 2013*

**Trigonometry **

simplify: tanx/secx+1
*November 20, 2013*

**Trig**

sin^2(34)+sin^2(48)+sin^2(56)+sin^2(42)
*November 19, 2013*

**Trig**

sqrt(100+(10cotx)^2)
*November 19, 2013*

**math 2nd grade**

24-16=8
*November 19, 2013*

**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%
*November 16, 2013*

**Hypothesis Test**

that isn't one of the choices :/
*November 16, 2013*

**Statistics**

Thank you so much !
*November 13, 2013*

**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
*November 13, 2013*

**Statistics**

That's what I originally did but it's not one of the correct answers
*November 13, 2013*

**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 ...
*November 13, 2013*

**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...
*November 13, 2013*

**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.
*September 20, 2013*

**Instructional materials, their preparation and use**

Which of the following would you use to sort through slides for a slide or injection?
*June 17, 2013*

**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 ...
*June 15, 2013*

**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. ...
*May 3, 2013*

**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...
*May 3, 2013*

**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 ...
*April 23, 2013*

**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 ...
*April 19, 2013*

**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 ...
*April 15, 2013*

**Teaching techniques**

Which learning technique is frequently used in the expository model of teaching?
*April 14, 2013*

**Calculus**

Find the second derivative of the function f(x)= t^2e^(-2t)
*April 10, 2013*

**Calculus**

Write the expression as the logarithm of a single quantity. ln 2 + 1/2 ln(x +1)-2 ln(1+ x^(1/2))
*April 10, 2013*

**Calculus**

Determine the function is concave upward and where it is concave downward f(x)= x / (x+1)
*March 20, 2013*

**Calculus**

Find the absolute maximum value and the absolute minimum value, f(x)= (x +1 )/ (x-1) on [2, 4]
*March 20, 2013*

**Calculus**

Find the absolute maximum value and the absolute minimum value, g(x)=1/8 x^2 - 4 x^(1/2) on [0, 9]
*March 20, 2013*

**College Math**

I need help solving these problems by using the substitution problem 2x-3y=16 5x+2y=21
*March 20, 2013*

**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?
*March 19, 2013*

**Calculus**

Find relative maxima and minima of g(x)= 2x^2+ 4000/x +10
*March 6, 2013*

**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.
*March 6, 2013*

**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 ...
*March 5, 2013*

**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?
*February 28, 2013*

**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?
*February 28, 2013*

**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?
*February 28, 2013*

**Math**

If Bob hikes 5/8 of a mile in 1/3 of an hour. How fast is going in miles per hour?
*January 23, 2013*

**Biology**

what two mutations cause a shift or after the sequence after the mutation?
*December 18, 2012*

**Biology**

do mutations occur in DNA or RNA? Explain
*December 18, 2012*

**Biology**

what is the difference between a gene mutation and a chromosomal mutation?
*December 18, 2012*

**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?
*December 9, 2012*

**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?
*December 9, 2012*

**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?
*September 20, 2012*

**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
*September 10, 2012*

**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
*August 18, 2012*

**Math**

How do you find the high and low estimate for 29 x 73 and 615 X 25?
*July 15, 2012*

**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.
*May 3, 2012*

**trig**

verify the identity algebraically- (5-5 cos x)(5+5 cos x)=25 (sin^x)
*March 12, 2012*

**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.
*February 1, 2012*

**Physics**

fbzffb
*December 19, 2011*

**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.
*December 14, 2011*

**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 ...
*December 14, 2011*

**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 = ...
*December 7, 2011*

**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...
*December 6, 2011*

**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 ...
*December 6, 2011*

**biology**

birds
*December 6, 2011*

**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 ...
*December 6, 2011*

**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 ...
*December 6, 2011*

**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 ...
*December 6, 2011*

**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 ...
*December 6, 2011*

**physics**

Alright. Thanks for the help!
*October 8, 2011*

**physics**

Oh okay. But then what kind of kinematics equation would you use?
*October 8, 2011*

**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
*October 8, 2011*

**Dimensional Analysis**

Convert 1.60ml into microliters
*September 12, 2011*

**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 ...
*August 28, 2011*

**calculus**

F(x)=square root(27x-x^4)
*July 28, 2011*

**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?
*May 13, 2011*

**Algebra**

What is the remainder when 13 to the 51st power is divided by 5?
*April 14, 2011*

**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?
*April 11, 2011*

**chemistry**

how much calcium oxide is recovered when 250 g calcium hydroxide are heated given the following reaction? Ca(OH)2 arrow CaO + H2O
*April 11, 2011*

**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?
*April 11, 2011*

**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 ...
*March 27, 2011*

**allgebra ll**

solve 3x=8=3x2 by completing the square
*February 13, 2011*

**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.
*January 28, 2011*

**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
*December 27, 2010*

**spanish3**

Translate: Sara always used to lose her keys. Is it? Sara siempre se le perdia los papeles.
*December 27, 2010*

**Chemistry**

for the same question: what is the rate of decomposition (in mol/L*hr) when C2H6= 0.00422 M?
*December 25, 2010*

**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...
*December 14, 2010*

**Math (Algebra)**

can someone help me
*July 26, 2010*