# alex

Popular questions and responses by alex-
## Algebra

Please Help! Given the following three points, find by hand the quadratic function they represent. (−1,−8), (0,−1),(1,2) A. f(x)=−3x2+4x−1 B. f(x)=−2x2+5x−1 C. f(x)=−3x2+10x−1 D. f(x)=−5x2+8x−1 Determine if the following set of

*asked on August 12, 2020* -
## 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* -
## Algebra

Please Help Guys! 1) Why is f(x)=(3x+13)2+89 not the vertex form of f(x)=9x2+2x+1? A.The expression has a constant outside of the squared term. B. The expression is not the product of two binomials. C. The variable x has a coefficient. D. Some of the terms

*asked on August 13, 2020* -
## Algebra

Please help.! 1) Given the following three points, find by hand the quadratic function they represent. (0,6), (2,16), (3, 33) A. f(x)=4x2−3x+6 B. f(x)=4x2+3x+6 C. f(x)=−4x2−3x+6 D. f(x)=−4x2+21x+6 2) Given the following three points, find by hand

*asked on August 11, 2020* -
## Chemistry Help

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

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

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

*asked on April 29, 2019* -
## US Government

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

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

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

*asked on October 26, 2015* -
## 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* -
## 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* -
## 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* -
## 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* -
## 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* -
## 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* -
## 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* -
## 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* -
## 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 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* -
## 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* -
## 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* -
## 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* -
## 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* -
## 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* -
## 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* -
## 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* -
## 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* -
## 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 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* -
## 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 12

Which character is described in these lines? (10 points) Lord of the Scyldings, this single petition? Not to refuse me, defender of warriors, Friend-lord of folks, so far have I sought thee, That I may unaided, my earlmen assisting me, This brave-mooded

*asked on August 30, 2014* -
## 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 the area of the shaded region. r^2=sin(2θ).

*asked on May 5, 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* -
## 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* -
## Grade 12 University physics

A 1.2kg block is dropped from 48cm above a spring in equilibrium. The force constant for the spring is 124N/m. Calculate the maximum compression in the spring.

*asked on June 16, 2011* -
## spanish

does "fin" have an accent?

*asked on March 3, 2010* -
## 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 a Cartesian equation for the curve and identify it. (r^2)cos(2θ)=1

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

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

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

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

*asked on May 11, 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* -
## 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* -
## 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* -
## 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* -
## French, foreign language

Hi, I need help with answering some questions for French Here's my work on them tell me what you came up with for each question that is incorrect: 1.C'est un plat typiquement français. On les prépare avec du beurre et de l'ail. Ce sont un escargot

*asked on March 17, 2015* -
## 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

A square sheet of cardboard 100 cm by 100 cm is to have corners of side length x cut out. These cutouts will create flaps that can be folded up to form a box with no lid. The length and width of the base of the box are given by the expression (100 – 2x),

*asked on January 11, 2015* -
## 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* -
## 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* -
## 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* -
## 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* -
## algebra

The strength of a wood beam varies inversely with its length. A beam is 33 feet long can support 1200 pounds. How much weight can a similar beam support if it is 23 feet long?

*asked on February 11, 2012* -
## 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* -
## Math

An unknown distribution has a mean of 80 and a standard deviation of 12. A sample size of 95 is drawn randomly from the population. Find the probability that the sum of the 95 values is less than 7,300. (Round your answer to four decimal places.)

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

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

*asked on November 19, 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* -
## Chemistry

Ammonia is composed of hydrogen and nitrogen in a ratio of 9.33 g of nitrogen to 2.00 g of hydrogen. If 2.19 g of nitrogen combined completely with hydrogen to form ammonia, what mass (g) of ammonia would be formed?

*asked on February 23, 2013* -
## statistics

Given the length an athlete throws a hammer is a normal random variable with mean 50 feet and standard deviation 5 feet, what is the probability he throws it between 50 feet and 60 feet?

*asked on October 19, 2012* -
## 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* -
## US Government

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

*asked on June 26, 2012* -
## 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* -
## math

Circumference= 65.94 in, Find the Diameter

*asked on April 3, 2019* -
## Physics

An iceberg has specific weight of 9000 N/m^3 in n ocean, which has a specific weight of 1000 N/m^3. Above the water surface, it was observed that a volume of 2800 m^3 of the iceberg protruded. Determine the volume of the iceberg below the free surface of

*asked on February 11, 2018* -
## Math

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* -
## 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* -
## 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* -
## 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* -
## Chemistry

In the carbon diselenide, CSe2, identify the number of σ and π bonds, the necessary hybridization scheme and the orbital overlap. Thanks

*asked on December 3, 2014* -
## Chemistry

What quantity of heat is required to convert 200g of ice at 0.00C into water at 50C? I know that im suppose to use the E=mc(Delta T) but im not sure how...

*asked on July 17, 2014* -
## high school algrebra 1

A youth group is planning a trip to a local amusement park. They are taking a van which holds 10 people. It will cost $25 for parking and tickets to enter the park are $18 per person. create an equation for this situation

*asked on June 10, 2014* -
## 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*