# Posts by alex

Total # Posts: 3,724

**World History**

Thanks!

**World History**

Under what circumstances does it appear that paleolithic humans first used boats?

**Stats**

84.13 - power

**Finance**

I can't seem to figure this problem out: You make $4,800 annual deposits into a retirement account that pays 10.5 percent interest compounded monthly. Required: How large will your account balance be in 30 years? I feel like I'm really close, though. Here is where I&#...

**government**

Ms sue,,,,, why don't you ever just give us the answer. You're wasting your time and all of ours. We don't have textbooks for online classes.

**Physics**

Carol drops a stone into a mineshaft 122.5m deep. Calculate the time from when she hears it hit the bottom of the shaft. Assume the speed of sound in the air 343 m/s.

**english**

Choose the answer that displays the correct spelling of the plural form of the words in parentheses. Ancient (Roman) used (goose) as (guard) to warn of (enemy) approaching the camp.

**Physics**

An aircraft starts from rest and accelerates at 42.5m/s^2 until it takes off at the end of the runway. How long will it take the aircraft to travel down the 2.6km runway? Answer is 11 seconds

**Physics**

How far will a car travel if it starts from rest and experiences an acceleration of magnitude 3.75m/2^2 forward for 5.65 s? Answer is 59.9m

**Physics**

How far will a car travel if it starts from rest and experiences an acceleration of magnitude 3.75m/2^2 forward for 5.65 s? Answer is 59.9m

**Physics**

How far will a humanoid robot travel in 3.0 s, accelerating at 1.0cm/s^2(forward) if its initial velocity is 5.0cm/s(forward) answer is 20cm (forward)

**math**

Each game wheel is divided into equal sections. The spinners on the game wheels are each spun once and the number each spinner lands on is recorded. What is the probability that both numbers are odd numbers?

**Math**

John has a box that contains one red ball and one blue ball. Every minute he reaches into the box and randomly takes out a ball from it (without looking). No matter which ball he took out, he puts it back together with another ball of the same color. Thus, after n minutes, the...

**Math**

572

**Physics**

A q = +3.00 mC test charge is placed inside a constant uniform electric field created in a parallel plate capacitor connected to a battery of unknown voltage. The capacitor is made of two parallel plates each with area equal to 0.250 m2 separated by a distance of 0....

**Physics**

A capacitor is constructed from two conducting with a plate separation of d. The voltage between the plates is 31.2 volts and the electric field between the two plates is measured to be E = 2805 V/m. What is the minimum amount of force needed to push an electron from the ...

**Physics**

A charge q=+5.11 mC (millicoulombs) has a mass of 0.00456 kg and is accelerated by two rings connected to a voltage source of 1378 volts. What is the velocity of the charge when it passes through the second ring?

**Chemistry**

For anyone who stumbles upon this page, DrBob222 made a mistake. Take note that the second reactant is H2O (l), not another 2HCl (g). Make sure to look up the dHf of H2O instead.

**statistics**

the mean of sat scores of a specific month is1000 with a standard deviation of 100. find the 90 percentiles . assume that the sat score is normal distributed

**math**

When the Senior class decided to order T-shirts, they were quoted a price of $7.50 per shirt plus a setup fee. The total cost for 300 shirts was $2,450. Write an equation in the form y = mx + b that represents the cost, y, for x shirts.

**math**

14.0

**math**

Eden finances a purchase of $611.03 by making monthly payments of $26.17 for 2 1/2 years. What annual interest rate, compounded monthly, is she being charged?

**Math**

how do i put 1/2, 2/3, 1/4, and 1/3 in order from least to greatest

**coefficients**

Name the coefficients in the polynomial 4x^2+3x-3

**Polymonimals!**

(m^2-m-4)+(m-5) m^2-2m+9 m^2+2m-9 m^2-2m-9* my answer m^2-9

**grammar**

In the following sentence identify the function of the infinitive (phrase). Is it too expensive to travel to Europe?

**biology urgent**

Glucose is transported into a cell through a process of co-transport, where it is moved against its concentration gradient through a membrane channel. Moving any molecule against its concentration gradient requires energy, but these glucose channels do not require ATP or any ...

**Math**

Tomeasure the length of a closet, Aaron used his foot and measured 6 foot-lengths. His father measured 4 foot-lengths. Could they be measuring the same closet? Explain.

**science**

how i s fishing line measured

**english**

16. Which one of the following sentences includes an error in subject-verb agreement? A. Either June or her children are going to the movie tonight. B. Laverne, who's married, and Shirley, who's single, both walk their dogs. C. Neither Hannibal nor her pups is in the ...

**english**

15. Which one of the following is a run-on sentence? A. Jerry told me he likes June, but Hank likes Julie better. B. I would talk to Frank if I knew him, but people don't ever talk to him. C. I'm not a fan of wrestling, but Leslie is. D. I think Frank might be too ...

**english**

Either Mark or his students _______ on the ferry boat. 13. If you want to use the present tense, which word would best fill the blank? A. were B. are C. was D. is B is the only present tense?

**english**

As it sailed south, Lord Nelson's great ship, Victory, met the Spanish fleet near Trafalgar. 12. The simple subject of the sentence is A. Lord Nelson. B. ship. C. fleet. D. south. I think best answer is B?

**College algebra**

Use the rational zeros theorem to find all the real zeros of the polynomial function. Use the zeros to factor f over the real numbers f(x)=9x^4+28x^3+66x^2+196x+21 Find the real zeros of f Use the real zeros to factor f f(x)=

**Polynomial help**

My answer is 5^10 * 5 5^6 * 5^5 5^7 * 5^4 The rules of multiplying exponential numbers with the same base is that you add the powers up.

**Polynomial help**

list 3 different ways to write 5^11 as the product of two powers.Explain why all of your expressions are equal to 5^11.

**College Algebra**

For the given functions f and g, find the following and state the domain of each result. f(x)=√x;g(x)=7x-2 (a)(f*g)(x)= What is the domain of f*g? (b) (f/g)(x)= What is the domain of f/g?

**polynominals**

(6h+1)-(9h+4) don't tell me the answer just give me the formula

**5th grade math (dividing fractions)**

Thanks!

**5th grade math (dividing fractions)**

Can you check this problem? How many twelfths are in one sixth? work: 1/6 divided by 1/12 = 1/6 * 12/1 = 2 ans= 2

**TRIG**

in an arithmetic sequence a1=4 and d=8 which term is 428 Show your work

**TRIG**

what is the explicit formula for the sequence 3,7,11,15

**TRIG**

determine the sum of the first 100 even integers SHOW YOUR WORK

**TRIG**

the population of a certain city is 1.3 million people. if the population is growing at the rate of 4% per year what will the population be in 8 years

**TRIG**

What is the 6th term of the geometric series with a1= -5 and r=2.5

**chemistry**

a)Calculate the pH of a solution of 0.75 M HNO3, which is a strong acid. b)Calculate the pH of a 1.0 L aqueous solution made from 0.80 mol CH3COOH and 0.20 mol KCH3COO (Ka = 1.8 x 10^-5).

**chemistry**

How many moles of sodium nitrate are in 0.65L of a 0.2 M NaNO solution?

**5th grade Language Arts**

Thanks for checking!

**5th grade Language Arts**

I was given an assignment to add suffixes ( -ible, -ive, and -ion) to certain root words. I can't seem to find any words for post using the above suffixes. I've tried searching dictionary and roots with post. Are there any words that can be made without changing the ...

**5th grade math (word problems)**

Thanks! I see what I did wrong for #2.

**5th grade math (word problems)**

Can you explain how to do the following problems? 1. Order these fractions from Greatest to least. 3/12, 5/8, 1/4, 7/8, 4/16 work: find least common denominator 3/12 = 12/48, 5/8 = 30/48, 1/4 = 12/48, 7/8 = 42/48 answer = 7/8, 5/8, since 3/12 and 1/4 are the same, which would ...

**chemistry**

What is the difference between the two strong acids, nitric and hydrochloric acid, when they behave as the oxidised forms in a reduction half-equation?

**Maths**

168 children went to a them park. If 1/3 of the girls is equal to 4/9 of the boys, how many boys went to the theme park?

**Slavery**

how much were slaves paid after the civil war

**Chemistry**

Determine the solubility of a sodium sulfate, Na2SO4, in grams per 100g of water, if 0.94 g of Na2SO4 is dissolved in 20 g of water to make a saturated solution.

**Math**

The length of a rectangle is 11 cm less than 3 times its width. If the area of the rectangle is 20 square inches, find the length and width

**chemistry**

Reverse the reactions. Label the acids and bases on the left-hand side of each of the reversed equations? 1. HCl + NH3 => NH4+ + Cl- 2.NH3 + H2O => NH4+ +OH- 3. HCl +H2O => H3O+ +Cl- 4. H3PO4 +H20 => HPO4^-2 +H3O+ 5.H2PO4- +H2O => HPO4^-2 +H3O+

**Grammar Please Help!!**

Viewed through a telescope, the planet Mars looks rust-red. Because rust is a large component of its soil.

**chemistry**

1.Does a pH of 8.6 describe a solution with a higher or lower hydronium ion concentration compared to a neutral solution? Is such as solution called acidic or basic? 2. Compared to a neutral solution, would you expect an acidic solution to have a higher or lower pH and a ...

**5th grade math (word problems)**

Thanks!!

**5th grade math (word problems)**

I'm not sure how to solve this: A group of friends went to an amusement park. 10 of them rode the ferris wheel, 15 rode carousel, and 11 rode the roller coaster. 7 of them rode both the ferris wheel & roller coaster. 4 rode both the ferris wheel & carousel. 5 rode both the...

**Speech**

thank you I appreciate your help:)

**Speech**

Analysing errors consumes time and money. In order to assure that the physical erosion processes are correctly identified both error analysis and standardisation of measuring techniques are necessary to limit uncertainty and to minimise misinterpretation For the last paragraph...

**Speech**

thank you very much i will repost once i have finished the whole thing.

**Speech**

Soil erosion research is difficult for several reasons notably because it is an intermittent process and thus, an extremely difficult phenomena to observe. In most studies, only the consequences are investigated. Environmental data measurement, processing and analysis are ...

**Speech**

Please rephrase the following sentences into a more simple manner. I need to give a presentation and i would like to write this out simpler. Thank you guys Research of soil erosion is difficult for several reasons, but particularly because soil erosion is an intermittent ...

**math**

what is 9/2 - 1/2

**math**

what is 9/2 - 1/2

**chemistry**

a)Name two cations whose salts are quite soluble in water? b)Name one anion whose salts are soluble in water.?

**5th grade math (word problems)**

Maria is packaging boxes into a carton that is 4 in. x 6 in. x 3 in. THe boxes are 2 in. x 1 in. x 1 in. How many boxes will fit in the carton? I'm not sure how to solve. I know volume = l x w x h. The carton has volume of 72 cubic inches (4 x 6 x 3). THe boxes are 2 cubic...

**5th grade math (word problems)**

thanks!

**5th grade math (word problems)**

Problem: A receipe for 4 dozen cookies requires 1 1/2 cups of flour. How much flour is needed for 1 dozen? work: 4 divided by 1 1/2 = 4/1 x 3/2 = 4/1 x 2/3 = 8/3 cups of flour Can you explain why i don't need to change 4 dozen to 48 and then divide by 1 1/2?

**Physics**

Thank you so much!

**Physics**

21. The Mariana trench is located in the Pacific Ocean at a depth of about 10300 m below the surface of the water. The density of seawater is 1025 kg/m3. If an underwater vehicle were to explore such a depth, what force would the water exert on the vehicle's observation ...

**Math**

I don't know

**chemistry**

For each of the following primary standard acids, write the titration equation and calculate the volume of 0.100 M NaOH required for the titration: (i) 300 mg benzoic acid (C6H5COOH) (ii) 200 mg oxalic acid dihydrate (C2O4H2.2H2O) Equations: (i): C6H5COOH +NaOH->NaC6H5COO +...

**chemistry**

Calculate the weight (in mg) of borax Na2B4O7.10H20 required to react with 25.0 mL if 0.100 M HCI No. moles HCl consumed = __________ moles No. moles borax required = __________ moles Molar mass of borax = __________ g mol-1 (Na2B4O7.10H2O) Weight borax required = __________ g...

**chemistry**

15.0 mL of 8.00 M NaOH was diluted with water to 500 mL. Calculate the molarity of the diluted NaOH solution. My calculations: 0.015L x 8.00moles/1L x 39.997/1mole = 4.8g M= (4.8g x 1mole/39.997) / 0.500L = 0.24M is my workings correct? Is there another way to get to this?

**chemistry**

STANDARDISATION OF 0.1 M HCl Borax dissolves slowly in water at room temperature. Why do we not use a stirring rod to mix the solution and speed up this stage of the experiment?

**5th grade math (word problems)**

thanks!

**5th grade math (word problems)**

Mrs. Jones bakes pies. She always cuts each pie into 8 slices. Ther are 13 slices left on the counter. How many pies are on the counter? (write as mixed number). work: 13/8 = 1 5/8 pies. Is this correct?

**chemistry**

what is the h+ of a solution with a ph of 10 at 25 degree celsius

**chemistry**

in relation to the pH of pure water at 25 degree Celsius where do the pH values of acid fall

**chemistry**

A 0.0583 mol sample of formaldehyde vapour, CH2O, was placed in a heated 0.359 L vessel and some of it decomposed. The reaction is CH2O(g)---> H2(g) + CO(g). At equilibrium, the CH2O concentration was 0.0449 M. What is the value of Kc for this reaction? my answer was 0....

**chemistry**

At high temperature, 2.00 mol of CH2O was placed in a 4.00 L container where it decomposed via the equilibrium CH2O(g)<=>CO(g)+H2(g) . At equilibrium, the concentration of CO was measured to be 0.0317 M. What is Kc for this reaction at this temperature?

**Physics**

6. When a mass is attached to a spring, the period of oscillation is approximately 2.0 seconds. When the mass attached to the spring is doubled, the period of oscillation is most nearly a) 0.5 s b) 1.0 s c) 1.4 s d) 2.0 s e) 2.8 s

**chemistry**

lem;tdgpH:T

**Gifted Chemistry**

Calculate the freezing point and boiling point of a solution that contains 56.8 g NaCl and 32.0 g KBr dissolved in 750.3 mL H2O.

**Grade 12 Calculus**

Determine the velocity and acceleration as functions of time, t, for s(t) = 45t − 5t^2, where s(t) represents the distance as a function of time. (Hint: velocity and acceleration correspond to the first and second derivatives of the distance)

**Chemistry**

Write the name and chemical formula of an amphoteric ion.

**chemistry**

Name three sodium salts that produce weak bases in aqueous solution.

**Physics**

A small steel sphere of mass 0.40 kg is attached by a 0.50 m long cord to a swivel pin set into the surface of a frictionless table top. The sphere moves in a circle on the horizontal surface with a speed of 6.0 m/s. a.) what is the magnitude of the centripetal acceleration of...

**Pre Calculus**

Thanks!

**Pre Calculus**

Having trouble verifying this identity... cscxtanx + secx= 2cosx This is what I've been trying (1/sinx)(sinx/cosx) + secx = 2cosx (1/cosx)+(1/cosx) = 2 cosx 2 secx = 2cosx that's what i ended up with, but i know it's now right. did i mess up with the algebra?

**Physics Electric Force**

Particle A of charge 2.76 10-4 C is at the origin, particle B of charge -6.54 10-4 C is at (4.00 m, 0), and particle C of charge 1.02 10-4 C is at (0, 3.00 m). We wish to find the net electric force on C. (a) What is the x component of the electric force exerted by A on C? (b...

**Physics**

Particle A of charge 2.76 10-4 C is at the origin, particle B of charge -6.54 10-4 C is at (4.00 m, 0), and particle C of charge 1.02 10-4 C is at (0, 3.00 m). We wish to find the net electric force on C.

**Math**

In a recent year there were the following numbers (in thousands) of licensed drivers in the United States. MALE: Age 19 and under - 4746 Age 20 - 1625 Age 21 - 1679 FEMALE: Age 19 and under - 4517 Age 20 - 1553 Age 21 - 1627 Choose one driver at random. Find the probability ...

**Geography**

What is the best way to answer the following question? Where is the Sea of Okhotsk located? I know that is runs along the coastline of Russia, but I'm not sure what else I should add. thanks

**Geography**

How many degrees are there between the equator and the tropic of cancer? I think the answer is 23.5, is that correct? Thanks

**music**

i have to speak a hindi poem onany one of the- ''life and workings of Dr. B. R. Ambedkar'' ''vaisakhi'' ''the foundation of khalsa panth'' In poetry competition. So please help.