# Posts by Martha

Total # Posts: 330

**algebra**

a rocket is launched at the top of a building. the height of the rocket (in meters) written in terms of time (seconds) can be modeled by h(t)=-4.9t^2+9.8t+73.5. what is the maximum height?

**Math**

How many real-number solutions does the equation have? -7x^2+6x+3=0 a) 1 b) 2*** c) none d) infintely

**Science**

Why does a thrown footbal have bpoth potential and kinetic energy? Whats is the combined energy called? The combined energy is mechanical. The kinetic is the physical throw of the ball and the potential energy is the postion the ball starts at before beiing thrown. How do the ...

**american gov**

Based on the excerpt, which statement best illustrates the impact of Lincoln’s proclamation on government? A >It increased the influence of the legislative branch. B. It caused the voters to elect a Democratic Congress. C> It allowed slaves to vote during the ...

**chemistry**

Why does CdS dissolve in HCL, when CuS and Bi2S3 will not?

**math**

I need to paint 2 walls of 125 feet long (W)x 8 feet tall (Height). how many gallons of paint do I need to buy to cover all the walls?

**Math**

On Saturday, Paula sold all her mangoes, oranges and grapefruits at the market. 60% of the fruits were mangoes, 25% of the fruits were oranges, Paula had 45 grapefruits. What percentage of the fruits sold were grapefruits?

**SCIENCES**

the major commercial aluminium ore is bauxite,AlO3.H2O(s).What is its molar mass?The analysis of a representive sample of bauxite shows it contains 70% by mass of Al2O3..What is the maximum mass of aluminium metal that could be obtained from 200kg of bauxite by the HAll ...

**Chemistry **

Use the Henderson Hasselbalch equations to solve for the Ka of the acid. Solution [HX]=0.200M and [NaX]=0.200M. They both have a pH of 4.11.

**ELA**

It is probably A

**chemistry**

How can lime be used yo improve the quality of soil degraded by industrial pollution?

**chemistry**

What will be the color of litmus paper when tested with lime?

**chemistry**

What is the name of the acid produced when CO2 reacts with water?

**chemistry**

What is the gas produced when lime is heated?

**chemistry**

How does ammonium ion act as an acid in the reaction between ammonium ion and water?

**chemistry**

What is the balanced equation of the reaction between ammonium ion amd water?

**chemistry**

What is the difference between the reaction of hydrochloric acid and water amd ethanoic acid and water?

**chemistry**

What os the balanced equation for the reaction between ethanoic acid and water?

**chemistry**

What is the balanced equation for reaction between hydrochloric acid and water?

**chemistry**

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. ...

**chemistry**

A 20ml hydrochloric acid is diluted by 80ml of distilled water, what would be the pH of the hydrochloric acid after the dilution?

**chemistry**

What will be the pH of hydrochloric acid after 0.01M of hydrochloric acid is diluted by the addition of 80ml distilled water?

**Trig**

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 ...

**Math**

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 ...

**history **

namibia's econoy during the 19th century

**development studies**

Namibia's economic history from the 19th century

**Mathematics**

Thank you guys so much

**Mathematics **

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?

**riddle**

I think the answer is food

**precalculus**

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 ...

**8th algebra**

Thank you

**8th algebra**

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 ...

**Chemistry**

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 ...

**Chemistry**

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...

**Algebra**

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

**partial maths**

x^3/(5x^3-1) resolve into a partial fraction

**History**

1. A d and e 2. B 3. A 100% correct

**MATH**

In a race, a triathlete runs 1/3 of total distance, cycles 2/5 of the total diatance and swims the ramaining distance. he swim 1.200 meters. What is the total distance of the race?

**Please help with my grandsons math**

a snail travels about 0.13 cm in one minutes.how far would it travel in 7 minutes if it keeps up the same speed?About how long would it take to go 3 m?

**Math**

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.

**math**

How many decimal digits in 2.00? 2 or 0?

**urgent math**

1.B 2.D 3.C 4.A and C 100%

**life orientation**

Three human rights violations and their examples

**life orientation**

express emotions on how bad corruption and fraud can be

**probability**

A dog allergy test for people has a 98% accuracy rate. Only 1% of the population has an allergy to dogs (actually it is much smaller than that!). Use a group of 100,000 people who've taken this test and the information provided to complete a table and answer the following ...

**solomon mahlangu high**

Identify three courses or study fields you are interested in following after grade12 write them down in order of preference

**6th grade math - ratios**

There are 39 counters in a box. How would you divide the counters to represent the ratio 5:8 ? Thank you.

**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.

**geometry**

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?

**7th grade geometry**

A circular path two feet wide has an inner diameter of 150 feet. How much farther is it around the outer edge of the path than around the inner edge ?

**circumference...math**

A Ferris wheel makes 12 revolutions per ride. How far would someone travel during one ride if the diameter is 63 feet?...thanks!

**Math**

9 people are coming to Sam's party. If each person eats 1/5 of the cake, how many slices does each person get?

**Sixth Grade Pre Algebra**

Thank you so much! I get it now😊

**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?

**Health**

Don't NEVER EVER TRUST MS.Sue

**chem**

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?

**Calculus**

Let u=f(r) and r=|x|=(x1^2 +···|xn^2)^1/2. Show that ∑ 1 to n (∂u/∂xj)^2 = (f′(r))^2

**math**

order of operations; simplify 4.5-10-2(1-2)+5 thank you!

**math**

is the number 1 a prime or composite number?

**Kgothala secondary**

Life oriatation, description of recent service delivery protest

**Kgothala secondary**

Life oriatation

**life orientation**

Evaluation of current protests

**life orientation**

Research on process of campaigns and protests

**Spanish**

Thanks so much for all your suggestions and all your time! I really appreciate all your help!

**Spanish**

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. ...

**social studies**

I have this question 2 for hw

**Math**

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% ...

**science**

How might the history of the US be different if the first European settlements had occurred on the west coast instead of the east coast

**english**

Thanks

**english**

I have to find the correct article that goes in the sentence. 1.)Usually ___ strange bird is a timid animal. Article- the.

**math**

Jane is organizing her 24 dolls into equal sized piles. What is the possible number of dolls that could be in each pile?

**statistics**

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...

**Physics**

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. ...

**Math**

A triangular piece of land has a base of 12 yards and a height of 16 yards.what is the area of the piece of land?

**physics**

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 ...

**physics**

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 ).

**physics**

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?

**math**

100

**math**

What numbers value is 100, 000 less than 1, 547, 298?

**statistics**

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

**Math**

Find the standard form of the equation of a line passing through (2, 3) and parallel to 3x + 5y = 2

**Math**

If x varies directly as y, and if x = 6 when y = 15, find y when x = 30

**Math**

If x varies inversely as y, and if x = 24 when y = 6, find x when y = 15.

**Math**

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.

**Math**

It takes Kelly 3/4 hour to bake a small loaf of bread.how many loaves of bread can she bake in 3 3/4 hours if she bakes one loaf at a time.

**Math**

Tickets for the school play were $6.00 and 1/5 of each ticket paid for the cost of printing the programs.how much of each ticket went towards printing the programs.

**Math**

The area of a rug was 45 square ft.the rug was separated equally into four colors.how many square feet were there in each color?

**Physics**

all of the above

**Science**

Explain how chemiosmosis functions in the cell. Discuss the energy transfers and explain the role of ATP in this process.

**Geometry**

In geometry, a common standard setting for enlarging on a copy machine is 121 percent. What does this mean?

**Geometry**

How many diagonals does a prism have whose base is a regular polygon with 3 sides?

**business math**

Sam Long anticipates he will need approximately $225,000 in 15 years to cover his 3-year-old daughter’s college bills for a 4-year degree.How much would he have to invest today at an interest rate of 8 percent compounded semiannually?

**math**

Joanne and Ed Greenwood built a new barn with an attached arena. To finance the loan, they paid $1,307 interest on $45,000 at 4.0%. What was the time, using exact interest?

**physical science**

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

**college algebra**

Find the intercepts of the function f(x). f(x) = (x - 2)2(x2 - 9)

**math**

16

**Math**

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...

**math**

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 ...

**Public Speaking**

Thanks so much for your help! I received a 100 :)

**Public Speaking**

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'...