# steven

Most popular questions and responses by steven-
## Math

A 100 point test contains a total of 20 questions. The multiple choice questions are worth 3 points each and the short response answer questions are worth 8 pints each. Write a system of linear equations that represents this situation, my answer is to

*asked on May 6, 2016* -
## Discrete Math

A bag contains 5 red marbles, 4 yellow marbles, 3 green marbles, 2 orange marbles and 2 purple marbles. If three marbles are removed, what is the probability that at least one of them is red?

*asked on January 19, 2014* -
## statistics

in a test for esp a subject is told that cards the experimenter can see but he cannot contain either a star, a circle, a wave, or a square. as the experimenter looks at each of 20 cards in turn, the subject names the shape on the card. a subject who is

*asked on March 24, 2010* -
## Math

The twice–differentiable function f is defined for all real numbers and satisfies the following conditions: f(0)=3 f′(0)=5 f″(0)=7 a)The function g is given by g(x)=e^ax+f(x) for all real numbers, where a is a constant. Find g ′(0) and g ″(0) in

*asked on December 29, 2014* -
## Geometry PLEASE HELP ME

ABC has vertices A(0, 6), B(4, 6), and C(1, 3). Sketch a graph of ABC and use it to find the orthocenter of ABC. Then list the steps you took to find the orthocenter, including any necessary points or slopes you had to derive.

*asked on December 11, 2012* -
## Science

1. How does sea-floor spreading occur? A. New materials are being added to the asthenosphere. B. Earthquakes brake apart the ocean floor. C. Sediments accumulate at the area of spreading. D. Molten material beneath Earth's crust rises to the surface.*

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

For the curve given by 4x^2+y^2=48+2xy, show that there is a point P with x-coordinate 2 at which the line tangent to the curve at P is horizontal.

*asked on December 31, 2014* -
## Physics

A total of 8.0 joules of work is done when a constant horizontal force of 2.0 newtons to the left is used to push a 3.0 kilogram box across a counter top. Determine the total horizontal distance the box moves.

*asked on January 16, 2012* -
## Physics

A 38.0-kg boy, riding a 2.37-kg skateboard at a velocity of +5.07 m/s across a level sidewalk, jumps forward to leap over a wall. Just after leaving contact with the board, the boy's velocity relative to the sidewalk is 6.06 m/s, 10.35° above the

*asked on October 15, 2014* -
## PHYSICS

A spinning wheel on a fireworks display is initially rotating in a counterclockwise direction. The wheel has an angular acceleration of -3.80 rad/s2. Because of this acceleration, the angular velocity of the wheel changes from its initial value to a final

*asked on November 14, 2008* -
## chemistry

A viral preparation was inactivated in a chemical bath. The activation process was found to be first order in virus concentration. The beginning of the experiment 2% of the virus was found to be inactivated per minute. [i] Evaluate k for the inactivation

*asked on November 11, 2015* -
## Chemistry

For the combustion of acetylene: 2C2H2(g) + 5O2(g) → 4CO2(g) + 2H2O(g) ΔH = -2511 kJ What is the enthalpy change when 2.80 g of C2H2 (g) reacts with excess oxygen.

*asked on October 29, 2017* -
## Chemistry

Cobalt-60, which undergoes beta decay, has a half-life of 5.26 yr. How many beta particles are emitted in 190s by a 3.10mg sample of Co-60? What is the activity of the sample in Bq?

*asked on February 13, 2012* -
## physics

4. A ball is thrown so that it just clears a 3m fence 18m away. If it left the hand 1.5m above the ground and at an angle of 60° with the horizontal, what was the initial velocity of the ball?

*asked on March 10, 2015* -
## Chemistry

Calculate the percent ionization of 0.120 M lactic acid (Ka=1.4*10^-4).

*asked on March 2, 2012* -
## math

Leslie has been offered the choice of either a $1,000 rebate or a 5.5 percent, 48-month loan for the new car she is purchasing. If Leslie will be financing $15,000 and she can get a 7.5 percent, 48-month loan at her credit union, should she take the $1,000

*asked on August 5, 2012* -
## reading

what assonance is in the poem daffodils by william-wordsworth?

*asked on October 25, 2013* -
## statistics

a binomial distribution will be approximately correct as a model for one of these two sports settings and for the other. explain why by briefly discussing both settings. a)a national football league kicker has made 80% of his field goal attempts in the

*asked on March 24, 2010* -
## Physics

The pilot of an aircraft wishes to fly due west in a 50.0 km/h wind blowing toward the south. The speed of the aircraft in the absence of a wind is 228 km/h. a) How many degrees from west should the aircraft head? Let clockwise be positive. Answer in units

*asked on October 15, 2014* -
## Chemistry

A 25.40 g sample of water containing tritium,(3/1)H , emits 1450 beta particles per second. Tritium is a weak beta emitter, with a half-life of 12.3 yr. What fraction of all the hydrogen in the water sample is tritium?

*asked on February 13, 2012* -
## Chemistry

A 50.6 mg sample of sodium perchlorate contains radioactive chlorine-36 (whose atomic mass is 36.0 amu). If 29.6% of the chlorine atoms in the sample are chlorine-36 and the remainder is naturally occurring nonradioactive chlorine atoms, how many

*asked on February 13, 2012* -
## Multiple Choice

Physics 2. Which of the following is equivalent to one ampere? (Points : 1) 10 s/10 C 10 C/10 m 1.5 C/1.5 s 15 C/10 s Question 3.3. A stream of moving charges results in a current of 5.6 A. How long does 116 C of charge take to flow past a fixed point?

*asked on May 8, 2014* -
## math

After a drought, the Great Salt Lake in Utah covered an area of 2450 kilometers squared or 35/64 the area of the lake under normal weather conditions. Find the area of Great Salt Lake under normal weather conditions.

*asked on February 3, 2017* -
## Physics

The drawing below shows a person who, starting from rest at the top of a cliff, swings down at the end of a rope, releases it, and falls into the water below. There are two paths by which the person can enter the water. Suppose he enters the water at a

*asked on October 3, 2014* -
## Physics

The drawing below shows a person who, starting from rest at the top of a cliff, swings down at the end of a rope, releases it, and falls into the water below. There are two paths by which the person can enter the water. Suppose he enters the water at a

*asked on October 3, 2014* -
## Physics

For this problem, ignore air resistance. You are to fire a rifle that shoots a particular bullet at 460 m/s at a target that is 45.7 m away and level with the rifle. Assuming that the acceleration due to gravity is 9.80 m/s², how high above the target

*asked on October 6, 2010* -
## accounting

The monetary contributions that the owners of IBM pay for shares of the company's stock are ____ resources for IBM. a. material b. financial c. human d. informational e. manufacturing Patents and copyrights confer value on a firm but do not exist

*asked on October 29, 2012* -
## Physics

Bats chirp at a high frequency which humans cannot hear. They use the echoes to detect small objects, such as insects, as small as one wavelength. If a bat were to emit a chirp at a frequency of 60.0 kHz and the speed of sound waves in the air are 340 m.s,

*asked on March 19, 2014* -
## chemistry

Copper(II) sulfide reacts with oxygen to produce copper (II) oxide plus sulfur dioxide. Suppose you start this reaction with 50.0 grams of copper(II) sulfide and 50.0 grams of oxygen and you actually produce 33.5 grams of copper(II) oxide. Calculate the

*asked on March 5, 2014* -
## Chemistry

what is the chemical equation of copper II oxide and carbon monoxide (include phases)?

*asked on March 9, 2012* -
## Math 12

A hard rubber ball is dropped from a moving van with a height of 5 metres. The ball rises to 80% of the previous height after each bounce. a) determine the total vertical distance the ball has traveled when it strikes the ground the eighth time. b)

*asked on May 11, 2012* -
## grade 11 math

a uniform-width boardwalk is built around the inside edge of a rectangular parkland that is 10m by 15 m. if the boardwalk takes up 20% of the lot, how wide is the boardwalk to the nearest centimetre?

*asked on July 7, 2009* -
## math

A rectangular field is to be enclosed by a fence. Two fences parallel to one side of the field divide the field into three rectangular fields. If 2400m of fence are available find the dimensions giving the max area.

*asked on July 12, 2009* -
## Chemistry

Complete and balance the following equation: NO2{-} + Cr2O7{2-} = Cr{3+} + NO3{-}

*asked on April 16, 2012* -
## math

For what values of x is the graph y=2/(5-x) concave upward? x-5 x>5 no values of x

*asked on February 2, 2015* -
## chemistry

Prepare 1.5 liters of 0.25 M Tris buffer, pH 7.5. Useful information: pKa Tris = 8.1 Formula weight of Tris (hydroxymethyl aminomethane) base = 121.1 Formula weight of Tris hydrochloride (acid form) = 158.0

*asked on September 26, 2012* -
## algebra

Who saw the brontosaurus enter the restaurant

*asked on May 21, 2011* -
## statistics

we developed a 95% z confidence interval for the mean BMI of women aged 20 to 29 years, based on a national random sample of 654 such women. we assumed there that the population standard deviation was known to be 7.5. in fact the sample data had mean BMI

*asked on April 20, 2010* -
## Math

George studied 1/4 hour on Monday and 3/8 hour on Tuesday. How long did he study altogether on both days?

*asked on June 18, 2013* -
## APUSH

how did huge industrial trusts develop in industries such as steel oil and banking, what was the effect on the economy?

*asked on January 24, 2012* -
## Math

A calendar that has one page per day is 7 inches long, 7 inches wide, and 2 inches high. What is the volume of one page of the calendar? Round your answer to the nearest thousandth.

*asked on April 28, 2014* -
## Statistics

Cola Corporation produces Orange Cola. The filling machines are adjusted to pour 12 ounces of soda into each 12-ounce can. However, the actual amount of soda poured into each can is not exactly 12 ounces; it varies from can to can. It has been observed

*asked on February 19, 2013* -
## Organic chemistry: dehydrohalogenation

Hello. I know you guys don't do organic chemistry but because I got so much help from you guys in general chemistry, I was wondering if you guys can help me out again. :P Here's my question. In dehydrohalogenation, how do you know whether a reaction is E1

*asked on October 10, 2007* -
## Economics

The market demand in a Bertrand duopoly is P = 15 - 4Q, and the marginal costs are $3. Fixed costs are zero for both firms. Which of the following statement(s) is/are true? a.P = $3. b.P = $10. c.P = $15. d.None of the statements associated with this

*asked on March 20, 2012* -
## chemistry

What volume of 0.123 M K3PO4 is required to react with 60 mL of 0.862 M MgCl2 according to the equation 2K3PO4+3MgCl2--> Mg3(PO4)2+6KCl Answer in units of mL.

*asked on March 10, 2010* -
## math

For the curve given by 4x^2+y^2=48+2xy show that ((dy)/(dx))=(y-4x)/(y-x)

*asked on December 31, 2014* -
## college chemistry

Copper(II) sulfide reacts with oxygen to produce copper (II) oxide plus sulfur dioxide. Suppose you start this reaction with 50.0 grams of copper(II) sulfide and 50.0 grams of oxygen and you actually produce 33.5 grams of copper(II) oxide. Calculate the

*asked on March 5, 2014* -
## Chemistry

Consider the voltaic cell illustrated in the figure, which is based on the cell reaction: Zn(s)+Cu^2+(aq) -> Zn^2+(aq)+Cu(s) Under standard conditions, what is the maximum electrical work, in joules, that the cell can accomplish if 52.0g of copper is

*asked on April 16, 2012* -
## math

Salma's penny bank is 1/2 full. After she adds 360 pennies, it is 4/5 full. How many pennies can Salma's bank hold?

*asked on March 30, 2012* -
## calculus-- need help desperately!

The Taylor series about x=5 for a certain function f converges to f(x) for all x in the interval of convergence. The nth derivative of f at x=5 is given by f^(n) (5)= (-1)^n(n!)/((2^n)(n+2)), and f(5)=1/2. Write third degree Taylor polynomial for f about

*asked on March 17, 2007* -
## math

For the curve given by 4x^2+y^2=48+2xy, find the positive y-coordinate given that the x-coordinate is 2.

*asked on December 31, 2014* -
## Physics

A 7300-kg satellite has an elliptical orbit, as in the figure. The point on the orbit that is farthest from the earth is called the apogee and is at the far right side of the drawing. The point on the orbit that is closest to the earth is called the

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

Consider the voltaic cell illustrated in the figure, which is based on the cell reaction: Zn(s)+Cu^2+(aq) -> Zn^2+(aq)+Cu(s) Under standard conditions, what is the maximum electrical work, in joules, that the cell can accomplish if 52.0g of copper is

*asked on April 16, 2012* -
## math

Last year's computer model is on sale for $799. You can add more memory to the computer. Each chip of 8 megabytes of memory costs $25. How many megabytes of memory can you add if you have at most $1,000 to spend.

*asked on March 1, 2011* -
## Physics

The wind exerts a force of 284 N North on a sailboat, while the water exerts a force of 132 N West on the sailboat. What is the magnitude of the net external force on the sailboat? Answer in units of N

*asked on October 27, 2011* -
## Physics

The two cubes in the drawing are made from the same material. The radiant energy per second emitted by the small cube is 3.70 J/s. What is the energy emitted per second by the larger one?

*asked on October 3, 2011* -
## Genetics

Hi, I really need help in how to approach this question: A species of tiny antelope, known as the zephyr, has an XY system of sex determination, similar to mammals. Zephyr males have small antlers and females do not. The antlers can be two pronged (2-pr)

*asked on February 6, 2011* -
## pre calc

evaluate the trigonometric function of the given quadrantal angle. tan 1440° Evaluate without using ratios in reference triangle. sec 3π/4

*asked on January 4, 2012* -
## calculus

A metal chain weighs 30 lbs and is 10 feet long. How much work is required to lift one end of the chain to a height of 15 feet (so that the other end of the chain will be at a height of 5 feet)?

*asked on December 1, 2011* -
## math Algebra I

Perimeter of table top is 28 feet. The difference between 4 times the length and 3 times the wide is 21 feet. Find the dimension. (Use system of linear equations to solve.)

*asked on May 13, 2011* -
## Chemistry

Copper(II) chloride and lead(II) nitrate react in aqueous solutions by double replacement. Write the balanced chemical equation, the over all ionic equation, and the net ionic equation for this reaction. If 16.06g of copper(II) chloride react, what is the

*asked on March 16, 2010* -
## Statistics-Probability

An instructor will choose 3 problems from a set of 7 containing 3 hard and 4 easy problems. If the selection is made at random, what is the probability that only the hard problems are chosen?

*asked on February 5, 2013* -
## Physics

A 50 kg satellite circles the earth in an orbit with a period of 110 min. What minimum energy E is required to change the orbit to one with a period of 320 min? Assume both the initial and final orbits are circular. The Earth’s radius is 6.37 × 10^6 m,

*asked on January 30, 2015* -
## algebra

Adult tickets for a play cost $16 and child tickets cost $6. If there were 25 people at a performance and the theater collected $260 from ticket sales, how many adults and how many children attended the play?

*asked on June 20, 2012* -
## Chemistry

Complete and balance the following equation: NO2{-} + Cr2O7{2-} = Cr{3+} + NO3{-}

*asked on April 16, 2012* -
## math

A right triangle has a hypotenuse of length 3.00 m, and one of its angles is 30.0°. What are the lengths of (a) the side opposite the 30.0° angle and (b) the side adjacent to the 30.0° angle?

*asked on July 19, 2009* -
## Math

5x/3+y=c 2y=c-4x x+y=6 What is c? I've tried substituting y as x-6 however I'm still not getting it.

*asked on August 29, 2015* -
## math

write and solve an equation to find the missing dimension of the rectangular prism. Volume= 1km cubic L=3/4 km W=2/3 km H= ?

*asked on April 28, 2014* -
## chemistry

A laboratory instructor gives you a test tube containing Ag+ ,Ba 2+ , and Cu 2+ ions. Devise a reaction scheme that would allow you to selectively precipitate each of these ions. Write a balanced net ionic equation for each precipitation reaction.

*asked on March 17, 2014* -
## Chemistry

What acid and what strong base would react in aqueous solution to produce the following salts in the formula equation? Write the balanced formula equation for each reaction. a) potassium perchlorate b) cesium nitrate c) calcium iodide I don't need just the

*asked on December 28, 2011* -
## algebra

Which of the following points lies on the circle whose center is at the origin and whose radius is 10 (-6,4) (/10,/10) (6,-8)

*asked on November 21, 2014* -
## math

A cube with side length 4 centimeters is 25% full of sand.What is the volume of the sand?

*asked on April 28, 2014* -
## math calculus

The marginal cost of a product is modeled by dC/dx= 16/cube root 16x + 3 where x is the number of units. When x = 17, C = 120. (a) Find the cost function. (Round your constant term to two decimal places.) c= (b) Find the cost of producing 90 units. (Round

*asked on May 28, 2013* -
## chemistry

identify the atoms that are being oxidized and reduced.. 2FeCl3 + 2KI --> 2FeCl2 + 2KCl + I2

*asked on March 29, 2010* -
## Statistics

Cola Corporation produces Orange Cola. The filling machines are adjusted to pour 12 ounces of soda into each 12-ounce can. However, the actual amount of soda poured into each can is not exactly 12 ounces; it varies from can to can. It has been observed

*asked on February 19, 2013* -
## math

3. (TCO A) The following questions are worth 5 points each. Please show all work. a. Inflation is expected to average five percent for the long term and Mr. Smith earned $74,000 this year, how much must he earn in 20 years just to keep up with inflation

*asked on August 5, 2012* -
## statistics

slot machines are now video games, with outcomes determined by random number generations. in the old days, slot machines were like this: you pull the lever to spin 3 wheels; each wheel has 20 symbols, all equally likely to show when the wheel stops

*asked on March 23, 2010* -
## college chemistry

How do I name the following compounds; K2S2O8, S2O8{-2}, Na2S2O3 and S2O3{-2}

*asked on February 25, 2009* -
## Physics

A boy weighing 40kg runs at 8.0m/s grabs a rope and swings of level ground. What maximum height does the child reach? How do I solve this?? it is under the conservation of energy section of work, power and energy. any help would be great! thanks

*asked on March 26, 2008* -
## chemistry

You need to determine the concentration of a sulfuric acid solution by titration with a standard sodium hydroxide solution. You have a 0.1896 M standard solution. You take a 25.00 mL sample of the original acid solution and dilute it to 250.0 mL. You then

*asked on April 11, 2014* -
## Physics

A uniform ladder of mass 30kg and length 5m rest against a smooth vertical wall with its lower end on a rough ground. The coefficient of friction is 0.4.the ladder is inclined at 60 degrees to the horizontal. Find how far a man of mass 80kg can climb

*asked on October 20, 2018* -
## Math

Jan is a 35-year-old individual who plans to retire at age 65. Between now and then $4000 is paid annually into her IRA account, which is anticipated to pay 5% compounded annually. How much will be in the account upon Jan’s retirement?

*asked on March 6, 2016* -
## Phyisics

1. Two concentric conducting spherical shells have radii of 0.126 m. and 0.225 m. The inner sphere bears a charge of -8.00E-08 C. An electron escapes from the inner sphere with negligible speed. Assuming that the region between the spheres is a vacuum,

*asked on March 18, 2015* -
## Physics

A camera falls from a blimp that is 399 m above the ground and rising at a speed of 9.75 m/s. Find the maximum height reached by the camera with respect to the ground. The acceleration of gravity is 9.8 m/s^2.Answer in units of m. b)Find the speed at which

*asked on October 10, 2014* -
## calculus 2

what is the polar area between r=5sinx and r=5cosx

*asked on December 7, 2011* -
## english

What nursery rhyme character was a "wise galoshes wearing feline" answer has 12 letters.

*asked on January 20, 2010* -
## Geometry

What is the perimeter of rectangle WXYZ, with vertices W(-3,7), X(-5,4), Y(1,0), and Z(3,3) to the nearest unit. PLEASE HELP. A. 36 UNITS B. 30 UNITS C. 22 UNITS D. 11 UNITS

*asked on September 15, 2015* -
## PHYSICS

Starting from rest, a 2.0 10-4-kg flea springs straight upward. While the flea is pushing off from the ground, the ground exerts an average upward force of 0.36 N on it. This force does +2.5 10-4 J of work on the flea. -How far does the flea move while

*asked on October 3, 2014* -
## PHYSICS

A golf club strikes a 0.041-kg golf ball in order to launch it from the tee. For simplicity, assume that the average net force applied to the ball acts parallel to the ball's motion, has a magnitude of 6400 N, and is in contact with the ball for a distance

*asked on October 3, 2014* -
## Statistics

A hospital claims that the mean waiting time at its emergency room is 25 minutes. A random sample of 16 patients produced a mean wait time of 27.5 minutes with a standard deviation of 4.8 minutes. Use the 1% level of significance to test is the wait time

*asked on March 28, 2013* -
## physics

A 55 kg student traveling in a car with a constant velocity has a kinetic energy of 1.6 104 J. What is the speedometer reading of the car in km/h?

*asked on September 17, 2010* -
## stats

you have torn a tendon and are facing surgery to repair it. the surgeon explains the risk to you: infection occurs 3% of such operations, the repair fails in 14%, and both infection and failure occur together in 1%. what percent of these operations succeed

*asked on March 23, 2010* -
## Maths

Mr Sanderson makes some cookies for a festival day. She gave 1/4 of the cookies to her sister and 1/3 of the remainder to a neighbour. If she had 120 cookies left, how many cookies did she make in the beginning? Linda spent 1/4 of her money on books, 1/3

*asked on July 15, 2016* -
## Physics

A 7300-kg satellite has an elliptical orbit, as in the figure. The point on the orbit that is farthest from the earth is called the apogee and is at the far right side of the drawing. The point on the orbit that is closest to the earth is called the

*asked on October 3, 2014* -
## physics

A bungee jumper jumps from a bridge with a 3 m long bungee cord. Once the cord starts to stretch, it acts like an ideal spring with coefficient of elasticity k=100 N/m. What should be the minimum height of the bridge in m so that this jump is safe for the

*asked on July 23, 2013* -
## chemistry

what is the entropy change that occurs when 500g of water ice melts at 0 degrees celsius and 1 atm. the heat of fusin for water ice under these conditions is 6.01 Kj/mol.

*asked on March 10, 2011* -
## Science

The law of conservation of energy states that energy can neither be created nor destroyed. In many instances it may look as though energy is gained or lost, but it is really only changed in form. How is the law of conservation of energy represented when an

*asked on January 5, 2011* -
## MO theory regarding heteronuclear diatomic molecul

Hi all I am having trouble finding the MO order for heteronuclear diatomic molecules: In my textbook, heteronuclear order is listed as: 1o 2o 3o 4o 1pi 5o 2pi 6o where o = sigma When I first saw it, I was confused; how can the above be correct? If one were

*asked on November 11, 2009* -
## Physics AP C

Two trains, each having a speed of 22 km/h, are headed at each other on the same straight track. A bird that can fly 60 km/h flies off the front of one train when they are 70 km apart and heads directly for the other train. On reaching the other train it

*asked on August 26, 2009* -
## Science

Which of the following questions is outside the scope of science? a. how are religion and philosophy different b.what is the diet of an american alligator c. how do humans digest protein d. how does gravity affect an airplane's motion

*asked on September 1, 2016*