Posts by martha
Total # Posts: 318
A titration to standardize a HCl solution was performed by taking 50.0ml hydrochloric acid in a flask with a few drops of phenolphthalein indicator. The burette was filled with 0.15 molar NaOH. The initial reading of the burette was 0.50ml and the final reading was 30.5ml. ...
March 14, 2017
Find all solutions in the interval [0,2pi) 4sin(x)cos(x)=1 2(2sinxcosx)=1 2sin2x=1 2x=1/2 x= pi/6, and 5pi/6 Then since its 2x i divided these answers by 2 and got pi/12 and 5pi/12 However, when i checked the answer key there solutions 13pi/12 and 17pi/12 were included ...
February 26, 2017
I need help solving for all solutions for this problem: cos 2x+ sin x= 0 I substituted cos 2x for cos^2x-sin^2x So it became cos^2(x)-sin^2(x) +sinx=0 Then i did 1-sin^2(x)-sin^2(x)+sinx=0 = 1-2sin^2(x)+sinx=0 = sinx(-2sinx+1)=-1 What did i do wrong?? the real solutions are ...
February 26, 2017
There are 2 red cars and 3 blue cars. The 5 cars contain a total of 12 people. No car has more than 4 people. Every car has at least 1 person. The only cars with the same number of people are the red cars. How many people are in 1 red car?
February 5, 2017
Can you please check and correct my answers? Convert to Rectangular: r*tan?/sec?=2 ________________________________________ y=2 y=½ x=2 x=½ answer: y=2 Given: 5cos6? What is the shape of the function? ________________________________________ Limacon Rose ...
December 11, 2016
I only need help writing the equation, not solving it. This is sothe problem. Manuel's budget allows no more than $50 per week for gasoline and car washes. Gasoline costs $2.30 per gallon, and a car wash costs $8.50. This week, Manuel gets a car wash. Write an inequality ...
October 31, 2016
74. Sodium hydrogen carbonate is also known as baking soda. When this compound is heated, it decomposes to sodium carbonate, carbon dioxide, and water vapor. Write the balanced equation for this reaction. What volume of carbon dioxide gas at 77 degrees C and 756 mmHg will be ...
September 30, 2016
Consider a mixture of two gases,A and B, confined in accosted vessel. A quantity of a third gas C, is added to the same vas sekar the same temperature. How does the addition of gas C affect the following: a. The partial pressure of gas A. b. The total pressure in the vassal, c...
September 30, 2016
Please how I solve this equation giving the domain of -3 I know that i have to replace the -3 where the x is but I do not know how to solve with the fraction. Thank you. -2x+1/3y=4
September 22, 2016
On a centimeter dot grid, draw all the possible rectangles with a perimeter of 14 cm and sides whose lengths are whole centimeters. Label the lengths of two adjacent sides of each rectangle.
May 25, 2016
6th grade math median range mode
The numbers are 47, 55, 46, 64, 69, and 52..... What is the mode?...I can't figure this out because I thought the mode was the number that appears most often. Thank you.
February 17, 2016
Triangle DEF contains two congruent acute angles. The sum of the measures of the two congruent acute angles is greater than 90 degrees. Anna concludes that the triangle must be an acute triangle. Which best describes her conclusion?
February 16, 2016
Sixth Grade Pre Algebra
Can someone please help me ? I think I'm supposed to put all the like terms together, but I can't remember how to do this. I asked my mom but she can't remember. Solve for x 6x - 6 equals 2x - 26 Solve for x 2x - 1 equals -5x - 85 Thank you very much. Can you explain?
January 21, 2016
A 1.27-g sample of a mixture of AgNO3 and NaNO3 is treated with excess Na2S(aq). The precipitate is filtered off, dried and weighed. The dried precipitate weighs 0.46 g. What is the percentage by mass of NaNO3 in the original mixture?
October 12, 2015
Can someone proof my spanish composition? Aprenda a vivir con la diabetes tipo 2 La diabetes tipo 2 es, desafortunadamente, una enfermedad muy común en los EEUU. Si usted ha sido diagnosticado con la diabetes tipo 2, es normal sentirse confundido, triste o enojado. ...
April 19, 2015
Assume the shoe is sold at 50% profit margin (profit as % of sales). If the cost of raw material were to increase by 50%, what would the new profit margin be? Cost of manufacturing a shoe: Raw materials = 25% Labor = 12.5% Marketing & Advertising = 25% Distribution = 25% ...
February 2, 2015
The following list is a sampling of the costs of various statistics textbooks used at several colleges. Give the upper confidence limit for a 95% confidence interval estimate for the mean cost of all statistics textbooks. 109.95; 92.00; 96.70; 84.85; 92.60; 84.45; 90.95; 77.00...
July 31, 2014
I know this is long but can someone just explain it to me? Please? Don't have to give the answer, I'm just confused :( 1. An experiment was devised to investigate the effects on the temperature of a cup of hot tea when lemon juice is added at different time intervals. ...
June 3, 2014
From a to b Wg= Fx cos 90 = 0 Wn= Fx cos 90 = 0 Wnet=Efk - Eik. Which is = to 1/2mVf^2 -1/2 mVi^2. Fxcos(0)= Efk. Cos of 0 =1. Vi =0 so use Efk Fx=1/2mVf^2 2Fx/m = Vf^2 Vf^2= square root of2Fx/m Vf= 9.77m/s X = distance, m= mass, F= force, V= velocity Efk = final kinetic ...
March 23, 2014
7. ( 11E ) a) Find the momentum of an automobile of mass 2630 kg traveling 21.0 ms .b) Find the velocity ( in km/h ) of a light auto of mass 1170 kg so that it has the same momentum as the auto in part ( a ).
March 23, 2014
52.(52G) A 110-kg crate, starting from rest, is pulled across a floor with a constant horizontal force of 350 N. For the first 15 m the floor is frictionless, and for the next 15 m the coefficient of friction is 0.30. What is the final speed of the crate?
March 23, 2014
A clinical trial test a method designed to increase probability of conceiving a girl.In study 375 were born and 300 were girls Use sample data to construct 99%confidence interval of percentage girls born
March 17, 2014
The 80 students in the 5th grade at north side elementary school voted for their favorite animal after a trip to the zoo.the elephant received 3/5 of the votes.how many votes did the elephant receive.
February 5, 2014
Sam Long anticipates he will need approximately $225,000 in 15 years to cover his 3-year-old daughters college bills for a 4-year degree.How much would he have to invest today at an interest rate of 8 percent compounded semiannually?
October 25, 2013
A 12-kg iron ball is dropped onto a pavement from a height of 90m. Suppose half of the heat generated goes into warming the ball. What is the temperature increase of the ball in degree C
October 6, 2013
James has 10,000 to invest. If he invest money in a savings account that pays 4% APR, calculate the following: a) how long will it take to have a total of 15,000 if interest is compounded quarterly (3months)? b)how much will he have after 7yrs if interest is compounded yearly...
April 28, 2013
Compound Interest Question James has 10,000 to invest. If he invest money in a savings account that pays 4% APR, calculate the following: a) how long will it take to have a total of 15,000 if interest is compounded quarterly (3months)? b)how much will he have after 7yrs if ...
April 28, 2013
To avoid speaking in monotone, a strategy to use can include: A. changing pitch and tone of voice. B. voice inflection. C. varying rate and pace of speaking. D. All of the above I read through my notes and I see A and B as answers, I don't see anything about C... But I'...
April 26, 2013
Wiley jumps straight up in the air from the edge of a cliff so that when he comes down he falls off the cliff. The cliff is 40 feet off the ground. His height t seconds after he jumps is s= -16t2 + 12t + 40.What is the maximum height? What is his maximum velocity?
November 12, 2012
let f(x) = 2x^5-5x^4 find open intervals on which f is a) increasing b)decreasing Find values of x at which f has c) relative max and min find open intervals d) concave upward e) concave downward c) find the inflection points of f
November 4, 2012
BENNY PLAYS TWO SPORTS. HE PLAYS SOCCER FOR 3/4 OF THE TIME AND PLAYS BASEBALL FOR 30-MINUTES. HOW MANY MORE MINUTES DOES HE PLAY SOCCER THAN BASEBALL? My answer is he plays soccer 7 minutes more. Am I correct. How do I make a diagram for this problem. Thanks
October 9, 2012