# Ray

Popular questions and responses by Ray-
## Math (Pre-Cal) (Exponential Functions)

A car was valued at $38,000 in the year 2003. The value depreciated to $11,000 by the year 2009. Assume that the car value continues to drop by the same percentage. -What will the value be in the year 2013?

*asked on February 19, 2016* -
## Math (Stats)

In order to predict y-values using the equation of a regression line, what must be true about the correlation coefficient of the variables? A. The correlation between variables must be an x-value of a point on the graph. B. The correlation between

*asked on March 11, 2017* -
## Math (Calculus) Integrals

Evaluate the integral using the following values. 8 ∫ x^3 dx = 1020 2 8 ∫ x dx = 30 2 8 ∫ dx = 6 2 2 ∫ x^3 dx = ? 2

*asked on April 4, 2017* -
## Math (Calculus) (Work)

Six and one-half foot-pounds of work is required to compress a spring 4 inches from its natural length. Find the work required to compress the spring an additional one-half inch. (Round your answer to two decimal places.) This is what I did so far: 4 in =

*asked on May 2, 2017* -
## Math (Stats)

What is the difference between class limits and class boundaries? A) Class limits are the numbers that separate classes without forming gaps between them. Class boundaries are the least and greatest numbers that can belong to the class. For integer data,

*asked on January 13, 2017* -
## Chemistry

A 522g piece of copper tubing is heated to 89.5C and placed in an insulated vessel containing 159g of water at 22.8C. Assuming no loss of water and a heat capacity for the vessel of 10.0J/K, what is the final temperature of the system ( c of copper = 0.387

*asked on November 11, 2008* -
## physics

I original volume is .021 at 24 degrees C, final volume is .019 at -18 degrees C how do I calculate the change in volume?

*asked on July 3, 2020* -
## Algebra

A car rental agency advertised renting a car for $24.95 per day and $0.33 per mile.If David rents this car for 3 days, how many whole miles can he drive on a $100 budget?

*asked on February 19, 2015* -
## Calculus

F(x) = x^5 ln x A) Find the interval on which f is increasing Find the interval on which f is decreasing B) Find the local minimum value of f C) find the inflection point (x,y) Find the interval in which f is concave up Find the interval in which f is

*asked on November 1, 2012* -
## physiscs

a pendulum of the length L is suspended from the ceiling of an elevator. When the elevator is at rest , the period of the pendulum is T. In instant when the pendulum reaches its highest position the elevator starts the free fall. What is the period of the

*asked on September 21, 2010* -
## economics

When Mcdonal's corp reduced the price of its big mac by 75% if consumers also purchase french fries and a soft drink. the company was hoping the novel promotion would receive its U.S. sales growth. It didn't. within two weeks, sales had fallen. Using your

*asked on May 27, 2009* -
## Math (Limits)

What is the limit of g(x)=x as x approaches pi? Would it just be pi??

*asked on October 2, 2016* -
## Physics

Some people believe that the Moon controls their activities. The Moon moves from being directly on the opposite side of Earth from you to be being directly overhead. Assume that the Earth-Moon (center-to-center) distance is 3.82 multiplied by 108 m and

*asked on November 9, 2009* -
## Statistics

The law of large numbers tells us what happens in the long run. Like many games of chance, the numbers racket has outcomes so variable - one three-digit number wins $600 and all others win nothing - that gamblers never reach "the long run." Even after many

*asked on February 25, 2014* -
## Math (Differentials)

Use differentials to approximate the value of the expression. cube root of 25 I set x=27 and dx=-2 and got ~3.0741, what did I do wrong?

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

The population of bacteria in a petri dish doubles every 12 h. The population of the bacteria is initially 500 organisms. How long will it take for the population of the bacteria to reach 800? Round your answer to the nearest tenth of an hour.

*asked on January 31, 2017* -
## Chemistry (molarity)

What would the effect on your molarity of NaOH be if you had added 35 mL of water to dissolve the KHP (acid) instead of 25 mL? Explain. My answer so far is that adding more water shouldn't affect the molarity at all because water does not account for the

*asked on November 10, 2016* -
## Math (Secant Lines)

Consider the function f(x)=sqrt(x) and the point P(4,2) on the graph of f? -Consider the graph f with secant lines passing through p(4,2) and Q(x,f(x)) for x-values 1, 3, and 5. -Find the slope of each secant line -Use the results to estimate the slope of

*asked on October 1, 2016* -
## Math (Calc) (Differential Equations)

The rate of change in the number of miles s of road cleared per hour by a snowplow is inversely proportional to the depth h of snow. That is, ds/dh = k/h Find s as a function of h given that s = 25 miles when h = 3 inches and s = 10 miles when h = 9 inches

*asked on May 31, 2017* -
## Math (misleading graphs) (Statistics)

When constructing a graph showing the population of two countries, an illustrator draws two different people with heights proportional to the populations. Identify a way in which the graph might be misleading. What is the general name for such graphs

*asked on January 16, 2017* -
## Math

On level ground, a 60-foot-tall vertical building casts a 10-foot shadow. at the same time, another vertical building casts a 25-foot shadow. how many feet tall is the second building?

*asked on December 1, 2016* -
## Math 142 (Pre-Cal) (Circles)

A wheel spins through 29 revolutions per minute. Find the angular velocity and the linear velocity if the radius of the wheel is 1.8 feet. w=? (rad/min) v=? (feet/min)

*asked on March 31, 2016* -
## Statistics

A class survey in a large class for first-year college students asked, "About how many minutes do you study on a typical weeknight?" The mean response of the 463 students was x = 118 minutes. Suppose that we know that the study time follows a Normal

*asked on February 25, 2014* -
## optics

A thin, double-convex lens has a refractive index of 1.50. The radius of curvature of the front surface is 15 cm and that of the rear surface is 10 cm. See sketch. (a) How far from the lens would an image of the sun be formed? (b) How far from the lens

*asked on May 29, 2013* -
## Chemistry

liquid hexane will react with gaseous oxygen to produce gaseous carbon dioxide and gaseous water. Suppose 7.8 g of hexane is mixed with 48.4 g of oxygen. Calculate the maximum mass of carbon dioxide that could be produced by the chemical reaction.

*asked on October 24, 2018* -
## Physics

A football is kicked at an angle of 45° to the horizontal over a defence line up with a velocity of 15m/s. Calculate the magnitude of the horizontal velocity of the ball at its highest point neglecting friction

*asked on June 14, 2018* -
## Math

A truck with 40-in.-diameter wheels is traveling at 50 mi/h. a) Find the angular speed of the wheels in rad/min b) How many revolutions per minute do the wheels make?

*asked on February 11, 2014* -
## chemistry

The pH of a .10M HOBr solution is 4.8 1. What is [H+] in that solution? 2. What is [OBr-]? What is [HOBr]? (where do the H+ and OBr ions come from?) 3. what is the value of Ka for HOBr? what is the value for pKa?

*asked on April 2, 2013* -
## physics

A battery with an emf of 14.5 V and internal resistance of 0.83 Ω is connected across a load resistor R. If the current in the circuit is 0.81 A, what is the value of R?

*asked on April 1, 2013* -
## science

A solution of HNO3 has a pH of 4.5, What is the molarity of HNo3?

*asked on April 26, 2011* -
## 11th grade

Consider two vectors where F1 = 38 N, F2 = 58 N, and = 240o and = 25o, measured from the positive x-axis with counter-clockwise being positive. What is the magnitude of the equilibriant?

*asked on December 5, 2010* -
## economics

Dell Computer Corp., the world's largest personal-computer maker, is keenly aware of everything its rival PC manaufacturers decide to go. Explain why Dell usually reacts more quickly and more substantially to pricing, product design, and advertising

*asked on May 27, 2009* -
## math

What is the least common multiple of 70, 60, and 50 ?

*asked on October 22, 2019* -
## Math (Calculus) (mean value theorem emergency)

Consider the graph of the function f(x)=x^2-x-12 a) Find the equation of the secant line joining the points (-2,-6) and (4,0). I got the equation of the secant line to be y=x-4 b) Use the Mean Value Theorem to determine a point c in the interval (-2,4)

*asked on November 19, 2016* -
## Math checking answers (Calculus Differentials)

The radius of a spherical balloon is measured as 8 inches, with a possible error of 0.02inch. a) Use differentials to approximate the possible propagated error in computing the volume of the sphere. b) Use differentials to approximate the possible

*asked on November 14, 2016* -
## Chemistry

Silicon carbide (SiC) is made by reacting sand (Silicon dioxide, SiO2) with powdered carbon at high temperature. Carbon monoxide is also formed. What is the percent yield if 51.4kg of SiC is recovered from processing 100.0kg of sand? What mass (in kg) of

*asked on October 25, 2016* -
## Math (Calculus)

Determine if each of the following functions is in Big-O, is Big-Omega and is Big-Theta of x: (Could be multiple) a) f(x)=10 b) f(x)=3x+7 C) f(x)=x^2+x+1 d) f(x)=5log(x) e) f(x)=|x| f) f(x)=x/2 I'm in calc 1 and I have no idea what's it even asking me.

*asked on October 22, 2016* -
## Math (Condensing logarithmic expression)

Write the expression as the logarithm of a single quantity 3[(ln x) -2ln(x^2+1)]+2 ln 5?

*asked on October 1, 2016* -
## Math (Parametrics)

Find the parametric equations of a unit circle where you start at point (0,1) at t=0 and you travel clockwise with a period of 2π? x(t)=? y(t)=?

*asked on June 3, 2016* -
## math

Jerry is packing cylindrical cans with diameter 6 in. and height 10 in. tightly into a box that measures 3 ft by 2 ft by 1 ft. All rows must contain the same number of cans. The cans can touch each other. He then fills all the empty space in the box with

*asked on April 14, 2015* -
## Calculus,Reaction rates

A man walks across a bridge at the rate of 5 ft/s as a boat passes directly beneath him at 10 ft/s. If the bridge is 10 ft above the boat, how fast are the man and the boat separating 1 second later?

*asked on November 30, 2014* -
## math

manuel and ruben played dominoes 24 times. Ruben has won 16 times. estimate the odds in favor of Manuel's winning the next match.

*asked on April 17, 2014* -
## health

the food group pyramid presents daily recommendations for: a.kind and amount of food to eat each day b.minimum amounts of nutrients needed c.amounts of each nutrient to consume daily d.maximum safe nutrient intakes Is it a? I am not sure

*asked on January 31, 2013* -
## British Literature

1)What theory does the narrator propose in the first paragraph of “The Mark of the Beast”? A) In Asia, Asian gods rather than the Christian God control most events. B) The British Empire is doomed because it disregards the values and traditions of

*asked on July 21, 2010* -
## Physics

A Texas cockroach of mass 0.17 kg runs counterclockwise around the rim of a lazy Susan (a circular disk mounted on a vertical axle) that has radius 15 cm, rotational inertia 5.5 10-3 kg·m2, and frictionless bearings. The cockroach's speed (relative to the

*asked on October 26, 2009* -
## Stats

Hello please help.. The owner of a computer repair shop has determined that their daily revenue has mean $7200 and standard deviation $1200. The daily revenue totals for the next 30 days will be monitored. What is the probability that the mean daily

*asked on April 14, 2020* -
## English

The boy whose mother died is around.What is the grammatical name and function.

*asked on January 20, 2020* -
## Psychology

Which theory might explain why people claim immigrants for the countries troubles even though there’s no evidence for this

*asked on December 11, 2019* -
## History

What happened to airplane manufacturing after World War II? 1 Airplane manufacturers began producing goods for the oil industry. 2 Airplane manufacturing rebounded and produced airplanes, parts, and equipment. 3 Airplane manufacturing decreased in Texas as

*asked on February 26, 2018* -
## Science

A man with a genetic disease marries a woman who does not carry the disease. It is not possible for their sons to have the disease. The disease must be X-linked dominat Y-linked dominat X-linked reccesive Y-linked reccesive I'm reposting this because i

*asked on February 8, 2018* -
## physics

circus juggler performs an act with balls that he tosses with his right hand and catches with his left had. Each ball is launched at an angle of 75° and reaches a maximum height 88 cm above the launching height. If it takes the juggler 0.2 s to catch a

*asked on November 16, 2017* -
## Math (calculus) (mean values)

A company introduces a new product for which the number of units sold S is given by the equation below, where t is the time in months. s(t)=155(7-9/(2+t)) a) Find the average rate of change of s(t) during the first year. Which my answer was 1395/28 b)

*asked on November 27, 2016* -
## Science (Stoichiometry with Gasses) (Chemistry)

If 1.00 kg of methane (CH4) is burned completely (in excess O2) and the CO2 produced is collected at 20°C and 1.00 atm, what volume (L) will this CO2 occupy??

*asked on November 16, 2016* -
## Chemistry (molarity) (sorta an emergency)

I'm doing a titration lab and writing a lab report where I'm sort of stuck on how exactly to find the concentration of HCl. These are the following info I have from the lab, Equation: HCl(aq)+NaOH(aq)-> H2O(l)+NaCl(aq) -Calculated molarity of NaOH solution

*asked on November 13, 2016* -
## math (horizontal tangent line)

Determine the point(s) if any at which the graph of the function has a horizontal tangent line. y=x^3+x I graphed this function out and it looks like there isn't any horizontal tangents. Am I correct or am I forgeting something? I tried finding the

*asked on October 22, 2016* -
## definite integral

approximate the value of the integral by use of the trapezoidal rule. n=8 a=0 b=4 sqrt 16-x^2

*asked on December 10, 2015* -
## Statistics

The law of large numbers tells us what happens in the long run. Like many games of chance, the numbers racket has outcomes so variable - one three-digit number wins $600 and all others win nothing - that gamblers never reach "the long run." Even after many

*asked on February 25, 2014* -
## physics

Object A is moving due east, while object B is moving due north. They collide and stick together in a completely inelastic collision. Momentum is conserved. Object A has a mass of mA = 17.5 kg and an initial velocity of = 8.50 m/s, due east. Object B,

*asked on October 10, 2013* -
## Chem

Citric acid (H3C6H5O7) is triprotic acid which reacts with NaOH according to the balanced chemical equation shown below what volume of 0.200m Naoh is required to titrate 7.50ml of lemon juice which is 0.245 m in citric acid? H3C6H5O7+3NaOH->Na3C6H5aO7+

*asked on April 21, 2013* -
## Physics

Imagine you are an astronaut who has landed on another planet and wants to determine the free-fall acceleration on that planet. In one of the experiments you decide to conduct, you use a pendulum 0.47 m long and find that the period of oscillation for this

*asked on November 3, 2012* -
## math

a recipe that will make 3 pie call for 7 cups of flour. write a proportion and solve it to find how many pies can be made with 28 cups of flour

*asked on September 10, 2012* -
## computer

If int main() { int a=1; int *p; how do the following statements differ 1) p=&a; 2) *p=&a; 3) p=a; 4) printf("%d",p); 5) printf("%d",*p); and what does int **a mean

*asked on July 8, 2012* -
## Physics

A pole-vaulter of mass 60.2 kg vaults to a height of 6.1 m before dropping to thick padding placed below to cushion her fall. (a) Find the speed with which she lands. (b) If the padding brings her to a stop in a time of 0.52 s, what is the average force on

*asked on March 4, 2012* -
## math

Explain another way to help you find the product of 8x6 without repeated addition.

*asked on February 8, 2012* -
## chemistry

Isotopes (select one or more): are chemicals that react only with protons. for an element have the same chemical properties. are atoms of an element that differ in the number of protons. are atoms of an element that differ in the number of neutrons. for an

*asked on December 12, 2011* -
## math

The distance from the center of a round table top to the edge of the table top is 4 ft. What is the area of the table top?

*asked on August 12, 2011* -
## Chemistry

A sample of glucose, C6H12O6, contains 1.300x10exponent21 atoms of carbon. How many atoms of Hydrogen does it contain? How many molecules of glucose does it contain?

*asked on June 15, 2011* -
## Physics

A block of wood with volume V floats in water with 0.68V submerged. In oil the block floats with 0.86V of its volume submerged. What's the density of the wood?

*asked on November 17, 2009* -
## Organisational Behaviour

Can give me example in relation to the 6 steps of the Rational Decision -Making Model? There are no examples in the textbook.

*asked on March 12, 2009* -
## Stats

Determine the sample size required to estimate the mean score on a standardized test within 44 points of the true mean with 9999% confidence. Assume that sequals=1313 based on earlier studies.

*asked on May 6, 2020* -
## Stats (regular)

In a college student poll, it is of interest to estimate the proportion p of students in favor of changing from a quarter-system to a semester-system. How many students should be polled so that p can be estimated to within 0.09 using a 99%

*asked on May 6, 2020* -
## chemistry

what volume of 0.5m BaCl 2 is needed to have 0.1 moles of BaCl 2 ?

*asked on March 24, 2020* -
## Physics

A tractor and tow truck have rubber tires on wet concrete. The tow truck drags the tractor at constant velocity while its brakes are locked. If the tow truck exerts a horizontal force of 1.0 x 10^4 N on the tractor, determine the mass of the tractor. Refer

*asked on April 12, 2019* -
## History

what lead to the belief that Galveston new government system, created after the Galveston hurricane of 1900 hurt the poor This is for connexus help

*asked on January 24, 2018* -
## Math (Planes)

Given the equation x + z = 2. Is P parallel to any of the coordinate planes? Is P perpendicular to any of the coordinate planes?

*asked on October 10, 2017* -
## Math (Double checking trig identity)

Since sec^2θ - 1 = tan^2θ I know this is trivial, but I want to make sure I'm doing this right before I apply it to the integral I'm trying to solve... If I have some constant a, (a^2secθ)^2 - (a^2)^2 If I wanted to change this to tan would it be:

*asked on May 19, 2017* -
## Math (Integrals) (Using given method)

I would like to solve the ∫sin^2(pix) dx Using the given substitution identity: sin^2(x) = (1/2)(1-cos2x) This is what I did so far: ∫sin^2(pix) let u = pix du = pi dx (1/pi)∫sin^2(u)du Applying the identity is where I'm lost on how to continue

*asked on May 9, 2017* -
## Chemistry

how much energy is released during the reaction of 2.5l diboron hexahydride with 5.65l chlorine gas?

*asked on April 11, 2017* -
## Math (Definite Integrals)

Sketch the region given by the definite integral. Use geometric shapes and formulas to evaluate the integral (a > 0, r > 0). r ∫ sqrt(r^2 - x^2) dx -r While I recognize that this looks similar to a circle function, I'm not sure how to graph and evaluate

*asked on April 6, 2017* -
## biology

HELP PLEASE!!!! How does the outcome of a chemical reaction that absorbs energy differ from one that releases energy?

*asked on March 28, 2017* -
## Computers (RAM)

Just giving this a shot, Which of the following statements about RAM are TRUE? Select all that apply. a) Any part of RAM can be accessed at any time. b) RAM is an area of a computer that holds programs and data that are waiting to be processed, to be

*asked on January 8, 2017* -
## Chemistry (identifying equations)

What type of reactions are these? Acid-base? Oxidation/Reduction? Precipitation? 1) Zn (s) + 2 HCl (aq) -> ZnCl2 (aq) + H2 (g) 2) Fe (s) + CuSO4 (aq) -> FeSO4 (aq) + Cu (s) 3) Fe (s) + Cu(NO)2 (aq) -> Fe(NO3)2 (aq) + Cu(s)

*asked on December 6, 2016* -
## Chemistry (Dilution) Help please?

Calculate how to prepare 100.0mL of a 1.25x10^-4 M aqueous solution of Fe(NO3)3(aq) by dilution of stock of 0.0025M Fe(NO3)3(aq) in a 100.0mL volumetric flask? I tried using the m1v1=m2v2 equation but it doesn't look like that equation would work for this

*asked on November 29, 2016* -
## Chemistry (Mass/volume)

What are factors that will contribute to achieving the lowest mass/volume ratio possible for an airbag? The "mass" includes the mass of the reactants, bag, and any additional materials you would use to make the airbag. The "volume" is of the inflated air

*asked on November 15, 2016* -
## Math (Derivative)

Assume that x and y are both differentiable functions of t and the required values of dy/dt and dx/dt xy=6 a) Find dy/dt, given x=8 and dx/dt=12 b) Find dx/dt, given x=1 and dy/dt=-8 I started with a and got dy/dt=dx/dt(-y/x) Plugging with the given values

*asked on November 13, 2016* -
## Chemistry (atoms)

How many atoms of oxygen, O, are in 0.0595 moles of water?

*asked on October 23, 2016* -
## Math (Polar to Cartesian Equation)

Convert the given polar equation to a Cartesian equation. r^2=4sec(theta)csc(theta)

*asked on June 7, 2016* -
## chemistry

Raising the temperature of a reacting system increases the rate of the reaction, but does NOT increase the:

*asked on October 1, 2015* -
## english plz plz help

Which of the following lines of dialogue best reveals Ram's false heritage to the landlord? a. "You look like a man who could tell me the right place to go." b. "I am an Untouchable from the heart of India." c. "Man is forever studying ways and means until

*asked on August 18, 2015* -
## Chemistry

How many moles of acetic acid are present in 10.00 mL if the concentration is 0.500M HC2H3O2?

*asked on August 12, 2015* -
## calcu

(4,-3) is on g For each of the following functions find a point on its graph. Enter exact answers. I cannot find the other three :( a) g(2x) - 5 ,(2,-8) b) 3g(x) + 1 c) -(g(1/3(x+4))-8) d) 1/2g(-5x-15)-8

*asked on October 17, 2014* -
## Statistics

Mileage tests were conducted on a randomly selected sample of 100 newly developed automobile tires. The results showed that the average tread life was 52,515 miles with a standard deviation of 3,550 miles. What is the best estimate of the average tread

*asked on April 20, 2014* -
## man

How to -2x+6y=-26 8x+6y=-1 6using elimination method

*asked on March 24, 2014* -
## Physics

A trash can with a mass of 5 kg has a coefficient of static friction of μs = 0.80 and a coefficient of kinetic friction of μk = 0.22. (The Active Figure applies to a similar situation, but the values of the mass, coefficient of static friction and

*asked on February 8, 2014* -
## US History

i really need help with this study guide 30.) Franklin D. Roosevelt became president during the Great Depression and established the New Deal in attempts to help the country recover. The New Deal was made up of several programs that are often times

*asked on January 8, 2014* -
## English

1.the trip led to an argument between Helen and ____ a.I b.me 2. It was ____ who demanded an apology from the newspaper. a.we b.us 3. We appreciated ____ writing a personal letter to explain his stand on the issue. a.his b.him 4. The most outspoken critics

*asked on December 6, 2013* -
## math

Write an algebraic expression that requires each of the following properties of real numbers to simplify, in the order given: the Distributive Property, the Associative Property of Addition, the Commutative Property of Addition, and the Distributive

*asked on September 17, 2013* -
## physics

An eyepiece is made of two positive thin lenses, each of focal length f = 20 mm, separated by a distance of 16 mm. (a) Where must a small object viewed by the eyepiece be placed so that the eye receives parallel light from the eyepiece? (b) Does the eye

*asked on May 29, 2013* -
## Chemistry

Calculate the heat released when 454 g of steam at 100.0C condenses and then cools to 30.0C. State your answer in calories.

*asked on April 3, 2013* -
## college algebra

please help me solve this equation x-1/3x-1/2x-5=0

*asked on February 25, 2013*