# Alex

Popular questions and responses by Alex-
## Chemistry Help

Write the net ionic equation for the reaction of calcium nitrate and sodium phosphate

*asked on November 14, 2012* -
## Physics

A girl of mass 55 kg throws a ball of mass 0.8 kg against a wall. The ball strikes the wall horizontally with a speed of 25 m/s, and it bounces back with the same speed. The ball is in contact with the wall 0.05 s. What is the average force exerted on the

*asked on March 30, 2012* -
## Chem

2HNO3(aq) + Sr(OH)2(aq) --> 2H2O(l) + Sr(NO3)2(aq)? Write the net ionic equation, including the phases. 2H^+(aq) + 2OH(aq) ---> 2H2O(l) Am I correct?

*asked on October 22, 2015* -
## Chemistry

I have a question about this one 2N2O(g) ⇋ O2(g) + 2N2(g), what happens to the equilibrium position if the pressure decreases? Is going to shift to the right or to the left???

*asked on October 21, 2012* -
## US Government

Why do we have more safeguards for accused criminals than the victims themselves?

*asked on July 18, 2012* -
## calculus

The differential equation below models the temperature of a 87°C cup of coffee in a 17°C room, where it is known that the coffee cools at a rate of 1°C per minute when its temperature is 67°C. Solve the differential equation to find an expression for

*asked on April 27, 2017* -
## physics

Driving in your car with a constant speed of v= 22 m/s, you encounter a bump in the road that has a circular cross-section, as indicated in the figure (Figure 1) . Part A If the radius of curvature of the bump is 52 m, find the apparent weight of a 66-kg

*asked on March 28, 2017* -
## Physics

A pile driver lifts a 450 kg weight and then lets it fall onto the end of a steel pipe that needs to be driven into the ground. A fall of 1.5 m drives the pipe in 45 cm. What is the average force exerted on the pipe?

*asked on October 30, 2016* -
## Physics

A spring is stretch 40mm by a force of 15N ...what's the work done

*asked on April 29, 2019* -
## math

Four corners are cut from a rectangular piece of cardboard that measures 5 ft by 3 ft. The cuts are x feet from the corners, as shown in the figure below. After the cuts are made, the sides of the rectangle are folded to form an open box. The area of the

*asked on January 15, 2015* -
## Statistics

Which of the following is NOT sensitive to extreme values? A) the range B) the standard deviation C) the interquartile range D) the coefficient of variation I pick B the standard deviation

*asked on May 27, 2011* -
## US Government

people who believe voting is important have high political ...? what clue:(8-letter word) ----c-c-.

*asked on June 26, 2012* -
## Chemistry - Please check

d) 2Al(s) + Fe2O3(s) 2Fe(l) + Al2O3(s) Oxidation 2Al(s) 2Al+ + 2e- Reduction Fe23+ + 3e- 2Fe(l) Oxidation numbers for chlorine HCl = -1 MnO2(s)= +4 KMnO4(s)= +7 Oxidation numbers for manganese Mn(s)= ? MnCl2(s)= +7 Mn2+(aq)= ? MnO4- =? And then

*asked on February 13, 2008* -
## Chemistry

Round each number to two significant figures: 233.356 0.002353 1.005 Can you please show me and explain how to do this? Im confused. thank you!!!

*asked on September 10, 2015* -
## statistic

A survey found that women's heights are normally distributed with mean 62.5 in. and standard deviation 2.7 in. The survey also found that men's heights are normally distributed with a mean 67.9 in. and standard deviation 2.8 . Complete parts a

*asked on July 29, 2016* -
## Physics

A 50 Kg box rests on a horizontal surface. The coefficient of Static friction between the box and surface is 0.30. The coeffient of Kinetic friction is 0.20. What is the frictional force on the box if a 140 N horizontal push is applied to it. If a 175 N

*asked on April 30, 2016* -
## algebra

Sal's Sandwich Shop sells wraps and sandwiches as part of its lunch specials. The profit on every sandwich is $2 and the profit on every wrap is $3. Sal made a profit of $1,470 from lunch specials last month. The equation 2x + 3y = 1,470 represents Sal's

*asked on October 14, 2015* -
## Algebra 2

A baseball player swings and hits a pop fly straight up in the air to the catcher. The height of the baseball in meters t seconds after it is hit is given by a quadratic function h(t) = −5t^2 + 10t + 1. What is the maximum height of the baseball?

*asked on May 1, 2012* -
## math

two boxes have the same volume. One box has a base that is 2 inches by 2 inces. The other box has a base that is 4 inches by 4 inches. How many tines as tall is the box with the smaller base

*asked on February 11, 2019* -
## French

3 - Au marché The new employee can't get anyone's order right. Say what each customer asked for and what the employee gave them. Modèle-je / des frites J'ai demandé des frites, mais il m'a donné du pain. 1. Malika / une pêche Malika demande une peche,

*asked on February 18, 2015* -
## english

Choose the correct sentence pattern for the sentence below. There is good reason to be thankful. E-V-S S-V-DO-OC S-LV-PA S-V-DO S-V-IO-DO S-V S-LV-PN Question pattern

*asked on January 23, 2015* -
## Physics

A quantity of monatomic ideal gas expands adiabatically from a volume of 2.0 liters to 6.0 liters. If the initial pressure is P0, what is the final pressure?

*asked on February 12, 2013* -
## 5th Grade Math

Glenda bought z containers of laundry detergent at $9 each. She gave the cashier $50. a. Find the change Glenda received in terms of z. b. If z = 3, how much change did Glenda receive?

*asked on January 22, 2013* -
## Algebra

A toy rocket that is shot in the air with an upward velocity of 48 feet per second can be modeled by the function f(t)=-16t^2+48t , where t is the time in seconds since the rocket was shot and f(t) is the rocket’s height. What is the maximum height the

*asked on July 7, 2014* -
## Chemistry

For C2H5NH3+, write an equation that shows how the cation acts as an acid. Why is my answer wrong? CH2H5NH3^+(aq) + H2O(l) ---> CH2H5NH2(aq) + H3O+(aq)

*asked on November 6, 2018* -
## Trigonometry

Determine the general solution of Sin2x=4cos2x thanks in advance

*asked on October 26, 2015* -
## order of operations

Find the value of the expression below for r=4 and t=2 t^3-r+20 divided by r 9 72 6* I chose this one 40

*asked on September 4, 2013* -
## Chemistry

Calculate the pH and the pOH of an aqueous solution that is 0.025 M in HCl(aq) and 0.075 M in HBr(aq) at 25°C.

*asked on October 6, 2012* -
## Chemistry

A 100.0 mL sample of 0.20M HF is titrated with 0.10M KOH. Determine the pH of the solution after the addition of 100.0 mL of KOH. The Ka of HF is 3.5 x 10^-4

*asked on April 7, 2011* -
## Physics

A plate falls vertically to the floor and breaks up into three pieces, which slide along the floor. Immediately after the impact, a 200g piece moves along the x-axis with a speed of 2.00m/s and a 235g piece moves along the the y axis with a speed of

*asked on November 12, 2014* -
## English

I don't quite understand the meaning of the story "Score/Score" by Phyllis Gotlieb. I can't seem to find much about it on the internet.

*asked on October 6, 2009* -
## Microeconomics

Larry, Moe, and Jo run the only saloon in town. Larry wants to sell as many drinks as possible without losing money. Jo wants the saloon to bring in as much revenue as possible. Moe wamts to make the largest possible profits. Using a single diagram of the

*asked on December 8, 2006* -
## UCF

What will be the change in enthalpy when 100.0 g of butane, C4H10, is burned in oxygen as shown in the thermochemical equation below? 2 C4H10(l) + 13 O2(g) → 8 CO2(g) + 10 H2O(g) ΔH = −5271 kJ −2636 kJ −4534 kJ −9087 kJ −1.817 × 104 kJ

*asked on April 2, 2014* -
## math

The UV index on a sunny day can be modeled by the function f(x)=-0.15(x-13)^2+7.6 where x represents the time of day on a 24-h clock and f(x) represents the UV index. At what time(s) was the UV index 7? (2 marks)

*asked on January 23, 2015* -
## Chemistry

Strong base is dissolved in 675 ml of 0.200 m weak acid (ka=3.25x10^-5) to make a buffer with a ph of 3.95. Assume that the volume remains constant when the base is added. HA + OH ---> H2O + A^- calculate the pka value of the acid and determine the number

*asked on November 9, 2011* -
## Physics

Water flows into one end of a horizontal, cylindrical pipe at 2.0 m/s. The pipe then narrows until its diameter at the opposite end is only 1/3 of that at the beginning. (a) What is the flow speed at the narrow end of the pipe? (b) What is the pressure

*asked on April 15, 2017* -
## Math

Courtney and Kurtis are planning to travel 160 km in a car by travelling at x kilometres per hour for the first half of the distance, and then increasing their speed by 10 km/h to finish the distance. Which is the correct simplified expression for the

*asked on December 10, 2014* -
## algebra

Tasha invests $5,000 annually at 6% and $5,000 annually at 8%. Thomas invests $10,000 annually at 7%. Which statement accurately compares the two investments if interest is compounded annually?

*asked on July 7, 2014* -
## Math! Please Help It's Due Today!!!!!

Let line l_1 be the graph of 5x + 8y = -9. Line l_2 is perpendicular to line l_1 and passes through the point (10,10). If line l_2 is the graph of the equation y=mx +b, then find m+b.

*asked on September 4, 2017* -
## physics

A test rocket is fired straight up from rest. The net acceleration is 20 m/s2 upward and continues for 4.0 seconds, at which time the rocket engines cease firing. What maximum elevation does the rocket reach?

*asked on June 15, 2015* -
## Algebra

Find k, given that (2,k) is equidistant from (3,7) and (9,1). The answer is : k=0 How do I solve this problem?

*asked on August 13, 2012* -
## calculus

Find the area of the shaded region. r^2=sin(2θ).

*asked on May 5, 2017* -
## chemistry

Mixtures of helium and oxygen are used in scuba diving tanks to help prevent ‘the bends’, a condition caused by nitrogen bubbles forming in the bloodstream. If 95 L of oxygen and 25 L of helium at STP are pumped into a scuba tank with a volume of 8.0

*asked on March 20, 2013* -
## math

jose said all of the multiples of 8 are also multiples of 2. jamila said that all of the multiples of 8 are also multiples of 4. who is correct. Explain

*asked on November 16, 2011* -
## Algebra

kind of function best models the data on the table used to differences or ratios 0 0.6 1 4.2 2 29.4 3 205.8 4 1440.6

*asked on April 25, 2019* -
## Math

In a large section of a statistics class, the points for the final exam are normally distributed, with a mean of 72 and a standard deviation of 9. Grades are to be assigned according to the following rule: The top 10% receive A's. The next 20% receive B's.

*asked on November 18, 2016* -
## math

Arley’s Bakery makes fat-free cookies that cost $1.60 each. Arley expects 40% of the cookies to fall apart and be discarded. Arley wants a 35% markup on cost and produces 200 cookies. Assume that Arley can sell the broken cookies for $1.50 each. What

*asked on June 20, 2016* -
## Physics

A rock is thrown directly upward from the edge of a flat roof of a building that is 56.3 meters tall. The rock misses the building on its way down, and is observed to strike the ground 4.00 seconds after being thrown. Take the acceleration due to gravity

*asked on May 27, 2014* -
## physics

A 0.395-kg blue bead slides on a frictionless, curved wire, starting from rest at point in the figure below, where h = 1.50 m. At point , the blue bead collides elastically with a 0.650-kg green bead at rest. Find the maximum height the green bead rises as

*asked on October 18, 2012* -
## physics

A point charge of 2.4 μC is located at the center of a spherical shell of radius 17 cm, which has a charge −2.4 μC uniformly distributed on its surface. Given: ke = 8.98755 × 109 Nm2/C2 . a)Find the electric field for all points outside the spherical

*asked on September 19, 2011* -
## math

Sixty-five randomly selected car salespersons were asked the number of cars they generally sell in one week. Fourteen people answered that they generally sell five cars; nineteen generally sell six cars; twelve generally sell seven cars; nine generally

*asked on April 17, 2018* -
## calculus

Find a Cartesian equation for the curve and identify it. (r^2)cos(2θ)=1

*asked on May 5, 2017* -
## Language Arts

1. Which sentence contains an opinion? (1 point) Thomas Jefferson supported American independence from Great Britain. He was a lawyer in his home state of Virginia. Jefferson authored the Declaration of Independence, the most important document in

*asked on December 11, 2015* -
## ENG1010

Which of the following is an announcement rather than a topic sentence? A) I want to talk about the increase in the divorce rate. B) Many people have trouble getting along with others. C) Almost one out of every two marriages ends in divorce. D) The

*asked on March 6, 2011* -
## Physics

Neutral metal sphere A, of mass 0.10kg, hangs from an insulating wire 2.0m long. An identical metal sphere B, with charge -q is brought into contact with sphere A. Sphere A goes 12 degrees away from Sphere B. Calculate the initial charge on Sphere B. Note:

*asked on May 3, 2008* -
## microeconomics

Mickey is very picky and insists that his mom makes his breakfast with equal parts of cereal and apple juice. Any other combination ends up on the floor. Cereal costs 4 cents per tablespoon and apple juice costs 6 cents per tablespoon. If his mom budgets

*asked on September 7, 2015* -
## physics

A skateboarder at a skate park rides along the path shown in (Figure 1) . a=2.7 m and b=1.0m If the speed of the skateboarder at point A is v=1.6m/s, what is her speed at point B? Assume that friction is negligible.

*asked on April 10, 2017* -
## French

Did I do this correctly: 1. Malika / une pêche Malika a demande une peche, mais il lui a donne une poire. 2. Soraya / une tomate Soraya a demande une tomate, mais il lui a donne un oignon. 3. Daniel / du pâté Daniel a demande du pate, mais il lui a

*asked on February 24, 2015* -
## math

Four corners are cut from a rectangular piece of cardboard that measures 5 ft by 3 ft. The cuts are x feet from the corners, as shown in the figure below. After the cuts are made, the sides of the rectangle are folded to form an open box. The area of the

*asked on January 22, 2015* -
## math

The line y=16x intersects the quadratic function y=x^2 at two points. What are the coordinates of the two points of intersection?

*asked on January 14, 2015* -
## Math

A ball is thrown straight up from a bridge over a river and falls into the water. The height, h, in meters, of the ball above the water t seconds after being thrown is approximately modeled by the relation h=-5t^2+10t+35. Can you please help me ! Show your

*asked on November 26, 2014* -
## Math

The value of k that makes the expression x^2 + 72x +k a perfect square trinomial is ?

*asked on October 28, 2014* -
## English

What is the meaning of the quote @Life is eternal; and love is immortal; and death is only a horizon; and a horizon is nothing save the limit of our sight." Especially the part- "and a horizon is nothing save the limit of our sight." Thank you

*asked on September 28, 2017* -
## calculus

Find the area enclosed by the curve x = (t^2)-2t, y = (t)^(1/2) and the y-axis.

*asked on May 5, 2017* -
## Chemistry

CO(g) effuses at a rate that is ______ times that of Xe(g) under the same conditions.

*asked on November 19, 2015* -
## Vocab

I’m excited about my vacation. The beach has been calling my name. A. Personification B. Irony C. Hyperbole D. Onomatopoeia A??

*asked on November 12, 2015* -
## Chemistry

if 5.00 ml of 1.66x10^-1 M HCl solution is diluted to exactly 250.0 ml with water, what is the concentration of the resulting solution?

*asked on November 16, 2014* -
## Math

Which of the following triangles cannot be solved using the sine law? a) angle a= 28 degrees, angle b= 75 degrees, side a= 24 cm b) side a=4 cm , side b= 11 cm c) angle a=28 degrees, angle c= 34 degrees , side b=5 cm d) angle b= 29 degrees, side b=5 cm,

*asked on September 22, 2014* -
## Equation help 2 questions

How many real number solutions does the equation have y=-4x^2+7x-8 none one two infinite How many real number solutions does the equation have y=3x^2+18x+27 none one two infinite Thank you!

*asked on April 2, 2014* -
## math

Matthew parks his car between Karen’s and Patrick’s apartment buildings. The car is 46 m in front of Karen’s apartment building. The angle of elevation from the car to the top of the building is 40°. Matthew’s car is 39 m away from Patrick’s

*asked on December 2, 2013* -
## Algebra 2

How much of a 60% orange juice drink must be mixed with 30 gallons of a 10% orange juice drink to obtain a mixture that is 50% orange juice.

*asked on May 1, 2012* -
## Literature 1010

Transitions function much like road signals. A) True B) False this question does not make sense. when i look in my book ans online, i do not see anything referring to the Transitions function can someone tell me what a transition function relating to

*asked on March 6, 2011* -
## physics

A 550-g ball traveling at 8.0 m/s undergoes a head-on elastic collision with a 250-g ball traveling toward it also at 8.0 m/s. What is the speed of the 250-g mass after the collision?

*asked on October 28, 2010* -
## spanish

does "fin" have an accent?

*asked on March 3, 2010* -
## History

Which of these was President Lincoln's central goal during the Civil War? A.To end slavery in all U.S. states B.To preserve the Union****** C.To keep the U.S. economy from collapsing D.To punish the Southern states for seceding Is it B

*asked on April 3, 2017* -
## algebra

You also have two options for lodging. Write an equation FOR EACH OPTION that depicts the total cost of your stay, y, based on the number of days, x. Bilton Hotel: $100/night but you must pay an additional one-time fee of $40 for parking and other fees

*asked on August 13, 2016* -
## Math

The rectangular backboard of a basketball court needs to be assembled. Its area is given as 18,900 cm2 and the width as 1.8 m. What is the backboard’s length in metres? m

*asked on April 30, 2016* -
## Math

In a triathlon, a contestant swims 5 km, cycles 30 km, and then runs 20 km. In general, a contestant runs at an average speed of x, swimsat an average speed of x/5, and cycles at an average speed of 5x, where x is in kilometres per hour. a) Determine an

*asked on January 6, 2015* -
## Econ

The process that produces Sonora Bars (a type of candy) is intended to produce bars with a mean weight of 55 gm. The process standard deviation is known to be 0.77 gm. A random sample of 49 candy bars yields a mean weight of 55.82 gm. Find the test

*asked on April 22, 2014* -
## Physics

A computer is reading data from a rotating CD-ROM. At a point that is 0.0368 m from the center of the disk, the centripetal acceleration is 274 m/s2. What is the centripetal acceleration at a point that is 0.0781 m from the center of the disc?

*asked on February 19, 2012* -
## Statistics

A person's level of blood glucose and diabetes are closely related. Let x be a random variable measured in milligrams of glucose per deciliter (1/10 of a liter) of blood. Suppose that after a 12-hour fast, the random variable x will have a distribution

*asked on June 20, 2010* -
## Chemistry

1.The Volume of oxygen required for the complete combustion of 500ML of ethyne at STP..A)2.00ML B)1.25 C)1.71 D)1.00 2.A Chemical Engineer finds that 250ml CuSO4 reacts with excess NaOH to create 2.37g of precipitate.Calculate the Concentration of

*asked on June 4, 2009* -
## Physics

A 5.0-kg box at the top of a 400cm ramp slides down 200 cm. How much gravitational potential energy was lost as the box slides from the top of the ramp to the 200 cm mark of the ramp? A cheerleader is thrown vertically upward into the air. As the

*asked on November 21, 2007* -
## chemistry

if 465 cm3 of sulphur iv oxide can diffuse through porous partition in 30seconds how long will an equal volume, 620cm3 of hydrogen sulphide take to diffuse through the same partition (h=1,s=32,o=16

*asked on May 3, 2019* -
## Chemistry

A particular natural gas consists, in mole percents, of 83.0% CH4, 11.2% C2H6, and 5.8% C3H8. A 385L sample of this gas is measured at 25C and 729mmHg, and is burned in an excess of oxygen. How much heat in kJ is involved in this reaction. I assume you use

*asked on March 19, 2019* -
## History

All day long and in all places I am always fastening upon you, stirring you and persuading you and reproaching you. You will not easily find another like me. Use the passage to answer the question. 1. In the passage, what Greek philosopher describes his

*asked on October 10, 2016* -
## French, foreign languages

Hi, I desperately need help with double object pronouns in French. Here are questions that I am working on and I can't make heads nor tails of them: L'agence de voyages a envoyé les billets d'avion à mes parents. Mes parents ont acheté de grandes

*asked on June 12, 2015* -
## Algebra

Evan washes two types of vehicles. It takes him 30 minutes to wash a car and 40 minutes to wash a truck. He charges $12 to wash a car and $15 to wash a truck. In 270 minutes, Evan made $105 washing cars and trucks. How many trucks did Evan wash?

*asked on July 4, 2014* -
## pre cal

f(x) = two divided by quantity x squared minus two x minus three Graph A coordinate axis scaled by one. Domain and Range : _____________________ x and y Intercept(s) : _____________________ Horizontal Asymptote(s) : ___________________ Vertical

*asked on June 23, 2014* -
## science

all of the following are explanations for glacial periods EXCEPT. a. varying solar energy b. volcanism c. biological organisms d. Earth's orbit's precession

*asked on January 14, 2014* -
## chemistry

Hydrogen iodide reacts with itself to give hydrogen and iodine. The equilibrium constant is about 2.0 x 10─3 at a particular temperature. If you were to place some hydrogen iodide in a container and seal the container, what would you expect to find at

*asked on April 10, 2013* -
## statistics

You are a travel agent and wish to estimate, with 98% confidence, the proportion of vacationers who use an online service or the Internet to make travel reservations. Your estimate must be accurate within 4% of the population proportion. a) No preliminary

*asked on April 6, 2011* -
## Literature 1010

A topic statement is made up of a limited topic and a writer's point about the limited topic? True Or False.

*asked on March 6, 2011* -
## pals help

An air-track cart with mass m1=0.29kg and initial speed v0=0.95m/s collides with and sticks to a second cart that is at rest initially. Part A If the mass of the second cart is m2=0.55kg, how much kinetic energy is lost as a result of the collision?

*asked on April 18, 2017* -
## Math

In a large section of a statistics class, the points for the final exam are normally distributed, with a mean of 72 and a standard deviation of 9. Grades are to be assigned according to the following rule: The top 10% receive A's. The next 20% receive B's.

*asked on November 18, 2016* -
## Geometry

I need help!!! a hemispherical bowl with radius 25cm contains water whose depth is 10cm. what is the water's surface area

*asked on March 31, 2014* -
## chemistry

In the following reaction, how many liters of oxygen produce 560 liters of carbon dioxide in the oxidation of methane, given that both gases are at STP? CH4 + 2O2 ¨ CO2 + 2H2O

*asked on March 18, 2014* -
## Property help

Which property is illustrated by the following statement (3z)xy=3(zx)y Associative property of multiplication Communative property of Multiplication Inverse property of multiplication Communative of Addition My answer is commnative property of addition am

*asked on September 23, 2013* -
## TRIG

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

*asked on May 11, 2013* -
## 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.

*asked on April 10, 2013*