Sunday

October 4, 2015
Total # Posts: 285

**Chemistry - Radioactivity**

The activity of a sample of Ba-137m has decreased by 75% from its initial activity after 5.10 minutes. What is the half-life of Ba-137m? What fraction of activity remains after 6.25 minutes? (A=Aoe (-kt); k = .693/t1/2)
*September 27, 2015*

**math**

Train #1 leaves san diego at 4pm. train #2 leaves san diego at 6pm.train #2 travels 42 mph faster than train #1. if train # 2 overtakes train #1 at 8pm, what is the speed of each train?
*September 17, 2015*

**math **

Please I need help with this problem. it took us 3 hour to drive to a concert.on his way home he increased his speed by 19 miles got home in 2 hours . what was the speed? thank you
*September 16, 2015*

**pre algebra**

hank you Reiny.
*September 16, 2015*

**pre algebra**

it took us 3 hour to drive to a concert.on his way home he increased his speed by 19 miles got home in 2 hours . what was the speed
*September 16, 2015*

**geometry**

The endpoints of are A(2, 2) and B(3, 8). is dilated by a scale factor of 3.5 with the origin as the center of dilation to give image . What are the slope (m) and length of ? Use the distance formula to help you decide: .
*September 11, 2015*

**Algebra**

The measure of the smallest angle of a triangle is one-fourth the measure of the largest angle. The measure of the second angle is 36 less than the measure of the largest angle.
*August 31, 2015*

**Maths pure, economics, business studies, geography **

Which careers or courses i should do doing those subjects
*August 8, 2015*

**Mathematics , business studies , economics , geography **

Which courses or careers i should follow doing those subjects
*August 8, 2015*

**Algebra 1**

thank you for all the help
*May 31, 2015*

**Algebra 1**

A right triangle has 1 leg that is 2" longer than the other leg. the length of the hypotenuse is sqrt 130" Find lengths of legs 0=2x^+4x-126
*May 31, 2015*

**Algebra**

The legs of an isosceles triangle are 0.3 foot less than twice the base. The perimeter of the triangle is 4.9 feet. What is the length of one of the triangle’s legs?
*May 1, 2015*

**Child Development**

Research has shown that most preschool A.don't use the words "think,"remember or pretend c. believe that an event can be known without being directly observes. D. often insist they've always known information they just learned
*March 11, 2015*

**Physics**

Calculate the energy released when 235 U fissions resulting in two lighter stable nuclei with mass numbers 140 and 93.Please help!
*March 4, 2015*

**Physics**

I used this equation: Change in x = (velocity^2/2*mu*gravity)
*February 11, 2015*

**Math**

A giant pumpkin is 90% water and weighs 250 pounds. The pumpkin is placed on display as the largest pumpkin of the year at the LA county fair. During the week-long fair, the pumpkin loses water from being outside in the heat. At the end of the week, the pumpkin is only 80% ...
*February 10, 2015*

**chemistry**

i want to neutralize a 10 ml 3 molar sulfuric acid using calcium carbonate but don't know how to do the math the explanation confused me. (also i have to use sig fig and uncertainty)
*February 10, 2015*

**chemistry**

How many grams of calcium carbonate would it take to neutralize if i have 10ml 3 molar sulfuric acid? (can this be explained in detail?)
*February 10, 2015*

**chemistry**

i think you meant carbonate not bicarbonate
*February 10, 2015*

**History Help?**

What role did Stephen Austin play in the settlement of Texas by American colonists? He defeated Santa Anna's army, making it safe for colonists in the region. He convinced American colonists in Texas to declare their independence from Mexico. He received a large land grant...
*December 1, 2014*

**Maths**

The nth term of a series is 2^n-1 +5n. Find the sum of the first n terms. (Hint: This is an expression in terms of n).
*December 1, 2014*

**Math (Can someone Help)**

The temperature was 48.2° when Marcy went to bed and 35.7° when she woke in the morning. What was the change in temperature? A: 83.9° B: 82.5° C: 13.5° D: 12.5° < -- ? Carlos bought 3 gallons of ice cream for $9.50. Which proportion can be used to ...
*November 13, 2014*

**Math *checking answers*?**

Yeah I noticed that, but I didn't pick either because they were the same. Thank you(:
*November 13, 2014*

**Math *checking answers*?**

The temperature was 48.2° when Marcy went to bed and 35.7° when she woke in the morning. What was the change in temperature? A: 83.9° B: 82.5° C: 13.5° D: 12.5° < -- ? Carlos bought 3 gallons of ice cream for $9.50. Which proportion can be used to ...
*November 13, 2014*

**Statistics**

In a population, heights of males are normally distributed with u=180 cm and sigma^2=16 cm^2, while the heights of females are normally distributed with u=170 cm and sigma^2= 25 cm^2. a) One random male and one random female are selected from the population i)What is the ...
*November 9, 2014*

**Art**

1. Why would an artist chose to use harmony in a piece of artwork? 2. Perspective drawings will utilize all methods listed here except? 3. To create an image that is not harmonious, an artist could...?
*November 3, 2014*

**Gramma**

To Ms. Sue: Thank you very, very much for your help.
*October 28, 2014*

**Gramma**

Ms. Sue please check this complex sentence. The high school band became ebullient upon recieving the news that they won first place in the band competition.
*October 28, 2014*

**Gramma**

Although his political campaign was fallacious, the people voted for him anyway. Ms Sue please check this thank you.
*October 28, 2014*

**Gramma**

How can I use the word fallacious in a complex sentence?
*October 28, 2014*

**English**

How is the word brusque used in a complex sentence? please give examples.
*October 28, 2014*

**physics**

A cable with 24.0N of tension pulls straight up on a 1.02kg block that is initially at rest What is the block's speed after being lifted 2.20m ? Solve this problem using work and energy. Express your answer with the appropriate units.
*October 26, 2014*

**physics**

why is it that drivers place cement blocks and other heavy items in the trucks of their vehicles? (think of friction and normal force)
*October 24, 2014*

**English**

@ words : 1- curtail 2- devastate 3- digress 4- incentive 5- incorporate 6- indispensable 7- intermittent 8- rigor 9- squander 10-succumb Linda never had to work hard to make good grades in high school. But in college, where the ___(8)___ of course work were greater, she soon ...
*October 23, 2014*

**math**

1/7 will be the ans
*October 20, 2014*

**math**

2/3 = 14/21 21-14-4 = the # of the beads left that # = 3 so 3 bead should be white
*October 20, 2014*

**Pre-Calc**

cuz you know that the angle is in the top left you can use tan(x) = y/x to calculate the angle(it must be bigger than 90) than use cos(x) on your cal to find cos(x) or you can use x^2 + y^2 = hyp^2 to find the hyp and do (-1/5)/(hyp length) to get cos(x)
*October 20, 2014*

**physics**

change in KE = 1/2 mv2^2 - 1/2mv1^2 = 1/2m(v2^2-v1^2) where v2 and v1 are the final and initial speeds 242 = KE plug in numbers to get ans(mass) :D
*October 20, 2014*

**Physics**

This is a question related to work. Today we had a pop quiz in my physics class and I am just trying to check my work here :D 1) if there is a 5 kg block on a horizontal table connected with string to a 3 kg block hanging off the side of the table through a pulley. Assume the ...
*October 20, 2014*

**math**

Okay if you submitted those answers you made a 50 like me. but i suppose thats what i get right. The answers are actually B A D B
*October 14, 2014*

**Finance**

Your program has a proposed RDT&E-funded project scheduled to start in January 2015 which is expected to take 16 months to complete. The project is expected to cost a total of $16 million (then-year dollars), with cost expected to be incurred at a rate of $1 million per month...
*October 8, 2014*

**math**

Suppose that a crayon weighs the same as a marker. You have a box of crayons, 4 extra crayons, and 20 markers. Let b be the number of crayons in the box. A scale balances with all the crayons on one side and all the markers on the other. You remove markers from the scale so ...
*October 2, 2014*

**factorise completely**

2ax - 3ay + 2x - 3y
*September 20, 2014*

**chemistry**

An ore contains Fe3O4 and no other iron. The iron in a 65.46 gram sample of the ore is all converted by a series of chemical reactions to Fe2O3. The mass of Fe2O3 is measured to be 37.9 grams. What was the percent Fe3O4 in the sample of ore? Answer in units of %
*September 7, 2014*

**Math**

x =2(y+3) or y=3+1/2x
*September 4, 2014*

**chemistry**

At what angle (in degrees) must {111} planes of platinum (Pt) be exposed to a collimated beam of thee X-rays in order to obtain by diffraction monochromatic CrKα radiation.
*August 26, 2014*

**chemistry**

Gallium Arsenide ---------------- The charge carrier density of GaAs at 31o C is 2.25x106 cm-3. What is the charge carrier density (in cm-3) at 175oC? (The bandgap of GaAs is 1.42 eV. ) I am trying with arrhenius relationship but get confused over "charge carrier density&...
*August 25, 2014*

**chemistry**

Gallium Arsenide ---------------- The charge carrier density of GaAs at 31o C is 2.25x106 cm-3. What is the charge carrier density (in cm-3) at 175oC? (The bandgap of GaAs is 1.42 eV. )
*August 25, 2014*

**math**

Kendra bought 4 paintings and wants to hang them side by side on a wall in her bedroom. However, only 3 of the paintings will fit side by side on this wall. How many different ways can Kendra arrange 3 of the 4 paintings on the wall?
*July 31, 2014*

**Practical english**

Which of the following sentences contains an indefinite pronoun? A. This is Mary's necklace.
*May 1, 2014*

**English **

Hello I need some ideas to elaborate on in an essay about the following question "1.According to Frankenstein what makes the Creature more “human,” his weaknesses or his strengths?Why?" Now I believe it is his weaknesses but i dont know what Victor ...
*February 16, 2014*

**Beacon Height**

what is the time for the first clock
*January 9, 2014*

**EARTH SCIENCE**

number one is absolutly D i had gotten that one right.
*January 7, 2014*

**Lit**

What is a basic draft for a claim (Toulmin) about the theme. For example, "The theme of the piece is "blah-blah" " doesn't have an argument. What does?
*December 15, 2013*

**Math**

50 x 50 x 50 x 50
*December 15, 2013*

**maths lite,life science,geography and tourism**

What career can I take
*October 3, 2013*

**Grammar Advisor**

Are these correct? I mark my answer with an X. 88. The reason to list all of the preliminary (non-procedural) information in a lesson plan is to be sure have considered each aspect. keep good records for your future needs. be able to communicate clearly with administrators, ...
*September 25, 2013*

**Grammar Advisor**

I just cannot figure out if these answers are correct or not. Can you please help me? 78. If the sound system hadn’t failed, last night’s show would have been better. This is a correct sentence using the 1st conditional form. x This is a correct sentence using the ...
*September 25, 2013*

**math**

what are the 5 number combo in 1 to 39
*September 8, 2013*

**Science**

Which of the following is an environmental concern of genetically engineered crops mentioned in your text? (Points : 1) Genetically modified crops lead to larger applications of toxic herbicides and insecticides. The genetic modification of crops increases soil erosion while ...
*August 21, 2013*

**math**

Joan receives an annual salary of $22,768.68. What is the total amount of her gross pay each period if she is paid monthly?
*August 14, 2013*

**math**

Erma is paid $516.72 biweekly. What are her annual earnings?
*August 14, 2013*

**math**

Sheila received a 6.5% commission on a house she sold for $110,400. How much commission did she receive?
*August 14, 2013*

**american history**

Under the _______ system, Spanish conquistadors were rewarded with local villages and control over the local labor force
*July 15, 2013*

**math **

Explain whether the following statement is true or false: “The ordered pair (1,5) is the same as the order pair (5,1).”
*July 2, 2013*

**Math**

can any one add or subtact this (m^2 - m - 4) + (m - 5)
*June 5, 2013*

**Combining Inequalities**

Some treasure has been buried at a point(x,y)on the grid, where x and y are whole numbers. Here are three clues to help you to find the treasure: Clue 1:x>2 Clue 2:x+y<8 Clue 3: 2y-x>0
*May 23, 2013*

**Science**

Which of the following is true about an object that floats in water? (1 point) The object is less dense than frozen water. The mass of the object is less than that of water. The density of the object is less than that of water. The volume of the water is greater than the ...
*April 19, 2013*

**math**

the floor area of a rectangular storm shelter is 65 square meters, and its length is 6.5 meteres. What is the width of the storm shelter
*January 23, 2013*

**Physical Science**

An exercise spring has a spring constant of 315 N/m. How much work is required to stretch the spring 30 cm? What force is needed to stretch the spring 30 cm?
*December 19, 2012*

**8th Grade Science**

Label these reactants and products: 3Fe + 2 O2> Fe3O4
*December 11, 2012*

**math**

thank you!
*October 30, 2012*

**math**

I am moving to a new house. My old house is 3 kilometers from my new house. How many meters is the old house from the new house?
*October 30, 2012*

**Psychology**

Sources of stress do not automatically cause stress-related problems. Moderators of stress, which can include our personal strengths, might mean that we can have a healthier and more productive life in spite of life's challenges, or maybe even because of them. As the text ...
*October 28, 2012*

**4 gr**

thank u :)
*September 27, 2012*

**4 gr**

forty people are lined up to ride the ski lift to the top of the mountain. Each chair on the holds 3 people. How many chairs will it take to get everyone up the mountain?
*September 27, 2012*

**arrays**

One band has fewer than 40 speakers. They stack them in a array exactly 9 high. How many speakers could they have? Explain how you know.
*September 20, 2012*

**arrays**

Another band has 48 speakers. They stack them at least 4 high, but no taller than 6 high. What are all the different arrays they can make?
*September 20, 2012*

**arrays**

One band has 30 speakers. They stack them at least 3 high, but no taller than 6 high. What are all the different arrays they could make?
*September 20, 2012*

**arrays**

thank u :)
*September 20, 2012*

**arrays**

Rock bands often stack their speakers in an array. One teen band has 24 speakers. They stack them at least 2 high, but no taller than 8 high. What are all the different arrays they can make.
*September 20, 2012*

**arrays**

another band has 48 speakers. they stack them at 4 high, but no taller than 6 high. what are all the different arrays they can make?
*September 20, 2012*

**arrays**

another band has 30 speakers. they stack them at least 4 high, but no taller than 6 high. what are all the different arrays they could make?
*September 20, 2012*

**math**

No way im in connections academy in 8th grade as well lol. We should totally get in contact sometime. i just got in this school so i may need help trying to figure it out.
*September 6, 2012*

**social studies**

Which of the following best describes the difference between a keyword and subject search? Please make selection! A keyword search uses subject headings, but a subject search does not A subject search can retrieve false hits, but a keyword search does not A subject search uses...
*August 21, 2012*

**vocabulary**

The ----------- definition of gloomy is dismal or depressing.
*June 18, 2012*

**Probability**

In a raffle there are four winning tickets from 12, What is the probability from six tickets there are two winners? Thank you in advance.
*May 12, 2012*

**LIfe orientation**

Identify and descriibe one environmental problem that causes ill health
*April 27, 2012*

**Life Orientation**

Describe one environmental problem that causes ill health,accidents,crises and disasters
*April 25, 2012*

**chemisttry**

how many ml of a 1 M NaOH solution do you need to add to a 250 ml flask and bring it to volume with deionized water to make a 0.12 M NaOH solution
*April 23, 2012*

**physics**

A piece of metal at 80 degrees celsius is placed in 1.2 L of water at 72 degrees celsius. The system is thermally isolated and reaches a final temperature of 75 degrees celsius. Estimate the approximate change in entrophy for this process.
*April 19, 2012*

**physics**

Explain how the specific heats of materials are measured using the technique of calorimetry.
*April 19, 2012*

**physics**

Heat is added to an ideal gas at 20 degrees Celsius. If the internal energy of the gas increases by a factor of three during this process, what is the final temperature?
*April 19, 2012*

**Finance**

The target capital structure for QM Industries is 39% common stock 6% is preferred stock, and 55% debt. If the costs of common equity for the firm is 18.2%, and the cost of preferred stock is 9.4%, the before tax cost of debt is 7.5%, and the firms tax rate is 35% what is QM&#...
*April 18, 2012*

**Math**

One bag contains 2 green marbles and 4 white marbles and a second bag contains 3 green marbles and 1 white marble. If Jon randomly draws one marble from each bag what is the probability that they are both green?
*April 15, 2012*

**Physics**

At a city park, a person throws some bread into a duck pond. Two 4.00-kg ducks and a 9.00-kg goose paddle rapidly toward the bread, as shown in our sketch (Intro 1 figure) . If the ducks swim at 1.10 m/s, and the goose swims with a speed of 1.30 m/s, the total momentum of the ...
*March 25, 2012*

**6th Grade Math**

Which of the following translations corresponds to the matrix ?
*March 19, 2012*

**calculus**

The circumference of a sphere was measured to be 74 cm with a possible error of 0.5 cm. (a) Use differentials to estimate the maximum error in the calculated surface area. (Round your answer to the nearest integer.) cm2 What is the relative error? (Round your answer to three ...
*March 18, 2012*

**Math**

Find the value of constant n if the lines y=(n-2)x+12 and 3x-4y+5=0 are: a) parallel and b) perpendicular to each other. Thanks in advance.
*March 3, 2012*

**Basic Math**

How do you solve: 5/30 + 3/40 + 1/8
*February 27, 2012*