Wednesday

March 4, 2015

March 4, 2015

Total # Posts: 144

**Statistics**

Let x and y be the amounts of time (in minutes) that a particular commuter must wait for a train on two independently selected days. Define a new random variable w by w = x + y, the sum of the two waiting times. The set of possible values for w is the interval from 0 to 2a (...
*February 27, 2015*

**child care**

an appropriate sensory motor for a child up to eight month of age is A. touching toys of a different shapes, sizes and texture B. playing with puzzles with a few large pieces C. drawing with crayons or markers D. stringing large bead on a shoelace
*October 14, 2014*

**child care**

children who attend a program that has some theoretical basis for planning have A. more material to play than those that have no theory B. more positive experience C. less marked developmental gain D. less positive experience
*October 14, 2014*

**child day care**

large scale entry doors shouldn't be used at child care facilities because they A. appeal to adult B. are inviting to small children C. can make children feel small and less welcome D. create a welcoming environment for children and staff
*October 14, 2014*

**child day care**

my budget allows me to buy only one software for my children ages 5-8. which one of the following packages would be best for this age group A. ages7-9 B. ages 6-9 C. ages 4-7 or ages 6 and up
*October 14, 2014*

**US History**

Describe the role of the Quakers, Puritans, and Indians and how each of these groups felt about these leading nations. (By leading nations I mean the three world powers; Great Britain, France, Spain) This is only half the question. I answered the first part which is Describing...
*September 12, 2014*

**Chemistry(Please help)**

Ok I think I understand now, thank you very much for the explanation and the website as well. It really helped!!
*September 2, 2014*

**Chemistry(Please help)**

For a carbon atom that is sp2 hybridized, I understand that the electron configuration would be Yes, 1s2 2s1 2p3 which is a 2s up arrow,and 3 orbtials that are 2p up arrows but then since the four bonds hybridize to form four sp3 hybrid bonds how do I write this? Also for an ...
*September 2, 2014*

**Chemistry**

Sorry, the electron config that I posted was for sp2 which I am still not sure is correct.
*September 1, 2014*

**Chemistry**

So the C in methane would be sp3 correct? So does this mean that the electron config would be 1s orbital with an up and down arrow, 2 sp2 orbitals with 3 single up arrows, and a 2p orbital with a single up arrow?
*September 1, 2014*

**Chemistry**

I am having trouble figuring out the electron configuration for a carbon atom when it is in a molecule such as methane. I know that the ground state configuration for carbon is 1s2 2s2 2p2 but im not sure how to figure it out when it is bonded to other atoms. Thank you for the...
*September 1, 2014*

**Math - Data Management**

If we take a sample of 2400 families with five children, a) what is the probability that a family will have exactly 2 girls? b) How many of the families would you expect to have exactly two girls?
*June 3, 2014*

**Geometry**

If the ratio of the areas of two similar hexagons is 4:49, find the ratio of their apothems
*April 16, 2014*

**Social Studies**

Why did The Aquarius lose its funding from the NOAA?
*March 12, 2014*

**College Chemistry**

When determining the vapor pressure of water, the bubble volume is 1.2mL at 5 degrees celsius. -How many moles of dry air were in the bubble? (assume 1 atm) -If the bubble volume is 8.6mL at 75 degrees celsius, what is the partial pressure of the dry air at this temp?
*April 18, 2013*

**College Chemistry**

When determining the vapor pressure of water, the bubble volume is 1.2mL at 5 degrees celsius. -How many moles of dry air were in the bubble? (assume 1 atm) -If the bubble volume is 8.6mL at 75 degrees celsius, what is the partial pressure of the dry air at this temp?
*April 18, 2013*

**College Chemistry**

When determining the vapor pressure of water, the bubble volume is 1.2mL at 5 degrees celsius. -How many moles of dry air were in the bubble? (assume 1 atm) -If the bubble volume is 8.6mL at 75 degrees celsius, what is the partial pressure of the dry air at this temp?
*April 18, 2013*

**robert**

We finally reached Enkhuizen, an ancient harbor town, where the brisk wind from the sea was blowing so hard that we had to hold on to hats, skirts, and scarves. We walked with farmers and their families to the ferry boat. The farmers were holding baskets full of chickens, ...
*March 8, 2013*

**Please help**

Which of the following groups of words in bold is nonrestrictive and should therefore be set off with commas in the sentence My yarn WHICH IS BLUE AND GRAY will make a very pretty scarf. Hats KNITTED BY MY MOTHER are worn all winter by my family. The person WHO TAUGHT HER TO ...
*March 8, 2013*

**Comma help**

thank you
*March 7, 2013*

**Comma help**

Choose the option that corrects the sentence below. If the sentence is correct, select “d. The sentence is correct.” Commander-in-Chief Sam Houston defeated the Mexican army and captured Santa Anna in 1836 A Commander-in-Chief, Sam Houston, defeated the Mexican army ...
*March 7, 2013*

**English help**

thank you
*March 5, 2013*

**English help**

add the comma to the sentence As they studied the film they noticed some rules of science at work i wrote mine like this As they studied the film, they noticed some rules of science at work
*March 5, 2013*

**Math help**

A pyramid has a height of 5 in. and a surface area of 90 in2. Find the surface area of a similar pyramid with a height of 10 in. Round to the nearest tenth, if necessary
*February 28, 2013*

**math help**

ind the radius of a sphere with a surface area of 804 cm2
*February 27, 2013*

**math help**

Find the lateral area of a cone with a radius of 7 ft. and a slant height of 13 ft. Use 3.14 for ð and round to the nearest tenth
*February 26, 2013*

**Science**

What is convection?
*February 24, 2013*

**Science**

Thanks!!
*February 23, 2013*

**Science**

What units of measurement do you use to measure the earth to... 1. Moon 2. Galaxy 3. Sun 4. Communication satellite 5. Pluto 6. Proxima Centauri
*February 23, 2013*

**Physics**

How fast must the ball rolled along the surface of a 70cm high table so that when it roll off the edge it will strike the floor at the same distance (70cm) from the point directly below the edge of the table.
*April 28, 2012*

**physics**

A boat propelled so as to travel with a speed of 0.50m/s in still water, moves directly ( in a straight line) across the river that is 60m wide. The rivers flows with a speed of 0.30m/s. How long in a seconds does it take the boat to across the river?
*April 27, 2012*

**Physics**

Pls sir, kindly send the solution to my email. thanks. 1)A boat propelled so as to travelled with a speed of 0.50m/s in still water, moves directly ( in straight line ) across a river that is 60m wides. The river flow with a speed of 0.30m/s. How long in seconds does it take ...
*April 27, 2012*

**Discrete Math**

1.Using the principle of inclusion-exclusion find the numbers of integers between 1 and 1000 (inclusive)that are divisible by at least one of 2,3,5,or 7? 2.A drug store sells gum, candy, and playing cards. 15 teenagers are in the store...the clerk notes after the teenagers ...
*April 16, 2012*

**geometry**

Just flip flop the two
*March 5, 2012*

**word problem**

26$
*February 16, 2012*

**calculus**

Thanks!
*February 5, 2012*

**calculus**

Find all solutions to the equation in the interval [0,2pi) Cosx-cos2x
*February 5, 2012*

**calculus**

Cos(pi/12) solve using half angle formula
*February 5, 2012*

**chemistry**

2.4
*February 1, 2012*

**trig**

Okay thank you for the help on one and three. In my book for number two it says the answer is sin1/2 which is approx. 0.479. I'm not sure how that answer comes about.
*January 8, 2012*

**trig**

solve for x in the following equations: 1) sin(arcsin x) = 1 2) 2arcsin x = 1 3) cos(arccos x) = 1/3
*January 8, 2012*

**marine science**

Which directions do the blood and water go in a fish gill?
*December 14, 2011*

**science**

if an objects moves 5 cm/h what is its rate expressed in cm/day
*September 23, 2011*

**science**

over seven days, a plant grew from 12 cm to 33 express its average growth rate in cm/day
*September 23, 2011*

**science**

if a car travels 93 km/h, what rate is it traveling in km/min
*September 23, 2011*

**algebra**

60 - (15)(2)/3
*May 24, 2011*

**Chemistry**

To ensure equal mixing of the solution
*March 26, 2011*

**chemistry**

Lead pipes were once used to transport drinking water and are still found in some older homes and city water systems. Suppose the lead concentration and pH of the water determined by lead (II) hydroxide (Ksp = 2.8x10^-16) dissolving to produce a saturated solution. What would ...
*March 25, 2011*

**general chemistry**

Let the fraction of Cl-35 be x and that of Cl-37 y. (x)(34.969)+(y)(36.966)=35.453 Since the total of x and y must equal one, substitute y=1-x. Solve for x. Solve for y. Multiply each one by 100 to convert to percent.
*March 25, 2011*

**Chemistry**

You're missing a key word in the problem. For what are you being asked to calculate? (calculate the __ of each of the following) Even without knowing the question I can tell you that answer cannot be zero if you are solving for the concentration of some species. All ...
*March 24, 2011*

**french**

Why must one say classe de francais, for french class, and not classe francaise? How does one know when to use de in a descriptive phrase?
*September 29, 2010*

**Pre-Cal**

Test for symmetry with respect to Q=pi/2, the polar axis, and the pole. r=6 sinQ I know I have to replace (r,Q) with (r,pi-Q) (r,-Q) and (-r,Q) so would that be (6,pi/2)? I do not know how to find the Q.
*May 5, 2010*

**Math**

Test for symmetry with repsect to Q=pi/2, the polar axis, and the pole. r=16cos 3Q r=16cos(3pi/3 + 3h) = 16(cos3pi/2 3h- sin 3pi/2 sin h) cos 3pi/2 = 0 sin 3pi/2 = -1 Not symmetrical My teacher said that this was wrong!Why?
*May 5, 2010*

**Math**

Use a graphing utility to graph the function. Then use the trace or table feature to identify the limit. lim 5/x-2 x-->2 I know I posted this question before but I am still having a hard time doing this. I pressed the y= button and typed the normal equation in: 5/x-2. Is ...
*May 4, 2010*

**Math**

Find an equation of the parabola. vertex:(-1,2) focus:(-1,0) (x+1)^2 = 4p(y-2) (x+1)^2 = 0(y-2) (x+1)^2 = (y-2) Correct?
*May 4, 2010*

**Math**

Find the vertex, focus and directrix of the parabola. 4x - y^2 - 2y - 33 = 0 y^2+2y+1 = -4x+33+1 (y+1)^2 = -4(x+8.5) vertex:(-1,-8.5) focus:(-2,-8.5) Directrix: x=0 Is this correct?
*May 4, 2010*

**Math**

Eliminate the parameter and write the corresponding rectangular equation whose graph represents the curve. x = sec Q y = cos Q x^2 + y^2 = 1/cos^2 + sin^2/cos^2 = x^2(1 +sin^2) = x^2(2-cos^2) x^2(2-1/x^2) = 2x^2 - 1 x^2 - y^2 = 1 My teacher said to use secant*cosine = 1. ...
*May 4, 2010*

**Math**

For the function x^2 + 2x - 4 , find lim f(h+4) - f(4) / h h-->0
*April 24, 2010*

**Math**

Test for symmetry with respect to Q=pi/2 , the polar axis and the pole. r = 16 cos3Q Please explain. I do not know how to do this. Thank You!!
*April 17, 2010*

**Math(Please help)**

Thank You!!
*April 16, 2010*

**Math(Please help)**

Projectile motion: Let's suppose you throw a ball straight up with an initial speed of 50 feet per second from a height of feet. a) Find the equation that describes the motion as a function of time. My answer was x = 0 and y=-16t^2+50t+6 b) How long is the ball in the air...
*April 16, 2010*

**Math**

Projectile motion: Let's suppose you throw a ball straight up with an initial speed of 50 feet per second from a height of feet. a) Find the equation that describes the motion as a function of time. My answer was x = 0 and y=-16t^2+50t+6 b) How long is the ball in the air...
*April 16, 2010*

**Math**

Eliminate the parameter and write the corresponding rectangular equation whose graph represents the curve. x = secQ Y = tanQ Would I use cos^2Q + sin^2Q = 1?
*April 16, 2010*

**Math**

Eliminate the parameter and write the corresponding rectangular equation whose graph represents the curve. x = sqrt t y = 1 - t
*April 15, 2010*

**Math**

Eliminate the parameter and write the corresponding rectangular equation whose graph represents the curve. x = sqrt t y = 1 - t
*April 15, 2010*

**Math**

I am trying to find the standard form of this equation for an ellipse. 9x^2 + 4y^2 - 36x + 8y + 31 = 0 First I grouped the x and y's together. 9x^2 - 36x + ? + 4y^2 + 8y + ? = -31 + ? + ? Then I factored the 9 and 4. 9(x^2-4x+4) + 4(x^2+2x+1) = -31+36+4 9(x-2)^2 + 4(x-1)^...
*April 15, 2010*

**Math**

Find an equation for the ellipse. center:(3,2) a=3c Foci:(1,2)(5,2) h=3 k=2 I do not know where to start.
*April 15, 2010*

**Math(Please check)**

I am trying to find the standard form of this equation for an ellipse. 9x^2 + 4y^2 - 36x + 8y + 31 = 0 First I grouped the x and y's together. 9x^2 - 36x + ? + 4y^2 + 8y + ? = -31 + ? + ? Then I factored the 9 and 4. 9(x^2-4x+4) + 4(x^2+2x+1) = -31+36+4 9(x-2)^2 + 4(x-1)^2...
*April 15, 2010*

**Math**

Thank You
*April 15, 2010*

**Math**

A boat is sailing due east parallel to the shoreline at a speed of 10 miles per hour. At a given time the bearing to the lighthouse is S 70 degrees E, and 15 minutes later the bearing is S 63 degrees E. Find the distance from the boat to the shoreline if the lighthouse is at ...
*April 15, 2010*

**Math**

Thank you!
*April 13, 2010*

**Math**

I need to show that the right side equals the left side but I am having a little trouble simplifying. k(2k+1) +(4(k+1)-1) = (k+1)(2(k+1)+1) k^2+2k+3 For the right side?
*April 13, 2010*

**Math**

I need to show that the right side equals the left side but I am having a little trouble simplifying. k(2k+1) +(4(k+1)-1) = (k+1)(2(k+1)+1) k^2+2k+3 For the right side?
*April 13, 2010*

**Math**

The lesson that I am working on is called mathematical induction. The only problem is that the lesson was not explained very clearly due to a problem with the recording so I have no idea how to complete this problem. Find p k+1(This is little under the p) for the given Pk(K is...
*April 6, 2010*

**Math**

Thank You!!
*April 6, 2010*

**Math**

Use the given information to solve the triangle. If two solutions exists, find both. A=110 degrees a=125 b=100 a is greater than b so I think that there is only one triangle. I am not sure where to go from here.
*April 6, 2010*

**Math**

Use the given information to solve the triangle. If two solutions exists, find both. A=110 degrees a=125 b=100 a is greater than b so I think that there is only one triangle. I am not sure where to go from here.
*April 6, 2010*

**Math**

Use the given information to solve the triangle. If two solutions exists, find both. A=110 degrees a=125 b=100 a is greater than b so I think that there is only one triangle. I am not sure where to go from here.
*April 5, 2010*

**Math**

Thank You
*April 5, 2010*

**Math**

Find the areaof the triangle having the indicated sides and angle. B = 72 degrees 30' a = 105 c = 64
*April 5, 2010*

**Pre-Cal**

Thank You
*April 4, 2010*

**Pre-Cal**

1) Write the first five temrs of the geometric sequence a1 = 2 r=sqrt3 I know the first term is 2 but the sqrt 3 threw me off so I do not know how to find the next numbers. 2) Find the nth term of the geometric sequence. a2 = 3 a5 = 3/64 n=1 I know the formula is a1^r n-1 but ...
*April 4, 2010*

**Pre-Cal(Please help)**

Answered Already
*April 4, 2010*

**Pre-Cal(Please help)**

1) Write the first five temrs of the geometric sequence a1 = 2 r=sqrt3 I know the first term is 2 but the sqrt 3 threw me off so I do not know how to find the next numbers. 2) Find the nth term of the geometric sequence. a2 = 3 a5 = 3/64 n=1 I know the formula is a1^r n-1 but ...
*April 4, 2010*

**Math**

Find the length of v. Inital point of v = (1,-3,4) Terminal point of v = (1,2,-2) Please help. I am not sure how to start! Thank you.
*April 1, 2010*

**Math(Please help)**

Find the length of v. Inital point of v = (1,-3,4) Terminal point of v = (1,2,-2) Please help. I am not sure how to start! Thank you.
*April 1, 2010*

**Math(Urgent Please help)**

Find the area of the parallelogram that has the vectors as adjacent sides. u = i + 2j + 2k V = i + k I know that the magnitude of the cross product results on the area. After I do the cross product then what to I do?
*April 1, 2010*

**Math(Please check)**

Find the cross product of the unit vectors. j X k My answer was -i. Am I correct?
*April 1, 2010*

**Math**

Find the length of v. Inital point of v = (1,-3,4) Terminal point of v = (1,2,-2) Please help. I am not sure how to start! Thank you.
*April 1, 2010*

**Math**

Determine two coterminal angles (one positive and one negative) for the given angle. Give your answer in radians. A) 8pi/9 B) 8pi/45 For 8pi/9 I added 18pi/9 which equals 26pi/9 - 18pi/9 = -10pi/9. I do not know how to find the positive one for 8pi/9 and I do not know what to...
*March 29, 2010*

**Math**

Determine two coterminal angles (one positive and one negative) for the given angle. Give your answer in radians. A) 8pi/9 B) 8pi/45 For 8pi/9 I added 18pi/9 which equals 26pi/9 - 18pi/9 = -10pi/9. I do not know how to find the positive one for 8pi/9 and I do not know what to ...
*March 29, 2010*

**Pre-Cal(Please help)**

Nevermind I think I figured it out.
*March 27, 2010*

**Pre-Cal(Please help)**

Use synthetic division to show that x is a solution of the third-degree polynomial equation, and use the result to factor the polynomial completely. List all the real zeros of the function. x^3 - 28x - 48 = 0 Value of x = -4 Please help!!Thank you
*March 27, 2010*

**Pre-Cal**

Thank You
*March 27, 2010*

**Pre-Cal(Please check)**

i did -2/3 divided by 15, 10, -6, 0 and 14 I got 15, 0, -6 , 4 ,11.4 Is this correct?
*March 27, 2010*

**Pre-Cal**

Express the function in the form f(x) = (x-k)q(x) + r for the given value of k. f(x) = 15x^4 + 10x^3 - 6x^2 + 14 Value of k = -2/3 I do not understand what I am suppose to do!
*March 27, 2010*

**Earth Science**

What is the major source of free oxygen in the atmosphere? Would it be trees?
*March 26, 2010*

**Earth Science**

which geologic era had the shorest time span and the longest time span? 1) Longest = paleozoic 20 shortest = cenozoic Is this correct?
*March 26, 2010*

**Earth Science**

What is the primary basis for differentiating the Eras?
*March 26, 2010*

**Math(Please help)**

divide by long division. divide x^3 + 4x^2 - 3x - 12 by x^2 - 3
*March 26, 2010*