# Maddy

Most popular questions and responses by Maddy-
## chemistry

4 FeO(s) + O2(g) ¨ 2 Fe2O3(s) calculate value of delta H i have done this 4(-272.0)+0->2(-825.5) and the products minus reactants and i got -563 but it is not right?!

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

HOW DO I DO THIS? A daredevil is shot out of a cannon at 45.0° to the horizontal with an initial speed of 28.0 m/s. A net is positioned a horizontal distance of 51.0 m from the cannon. At what height above the cannon should the net be placed in order to

*asked on September 30, 2010* -
## math

A pair of dice is rolled once. suppose you lose $9 if the dice sum to 9 and win $11 if the dice sum to 4 or 6. how much should you win or lose if any other number turns up in order for the game to be fair?

*asked on October 23, 2012* -
## math

Farmer Brown had ducks and cows. One day she noticed that the animals had a total of 12 heads and 32 feet. How many of the animals were ducks and how many were cows?

*asked on March 16, 2009* -
## Chem

If a .750g sample of magnesium chloride is dissolved in water and then treated with a silver nitrate solution how many grams of silver chloride should be collected? I don't understand what my first step should be. The balanced equation is

*asked on April 9, 2015* -
## Chemistry

A scientist wants to make a solution of tribasic sodium phosphate, , for a laboratory experiment. How many grams of will be needed to produce 625 of a solution that has a concentration of ions of 0.800

*asked on October 13, 2011* -
## Physics

A large statue in a crate is being moved. The mass of the statue and the crate is 150 kg. As the statue slides down a ramp inclined at 40.0°, the curator pushes up, parallel to the ramp’s surface, so that the crate does not accelerate. If the statue

*asked on December 5, 2015* -
## Social Studies

Read the passage and answer the question that follows: John Brown, supported by abolitionists and Republicans, tried to start a slave revolt. Therefore be it resolved that the defense of slavery is a common cause to all Southern states. At the call of any

*asked on May 6, 2015* -
## physics

One of the fastest recorded pitches in major-league baseball, thrown by Billy Wagner in 2003, was clocked at 101.0 mi/h. If a pitch were thrown horizontally with this velocity, how far would the ball fall vertically by the time it reached home plate, 60.5

*asked on September 30, 2010* -
## science

A 68.4g sample of Potassium Chloride was added to 200g of water at 20 degrees celsius. Is the solution saturated, unsaturated, or supersaturated?

*asked on January 3, 2012* -
## AP Physics

Jean, who likes physics experiments, dangles her watch from a thin piece of string while the jetliner she is in takes off from Dulles Airport (Fig. 4-55). She notices that the string makes an angle of 24° with respect to the vertical while the aircraft

*asked on November 14, 2010* -
## Physics

A 35 micro coulomb point charge is placed 32 cm from an identical 35 micro coulomb charge. How much work would be required to move a 0.5 micro coullomb test charge from a point midway between them to a point 12 cm closer to either of the charges?

*asked on February 11, 2016* -
## math

ABCD is a quadrilateral inscribed in a circle, as shown below: What equation can be used to solve for angle A? (x + 16) + (6x − 4) = 180 (x + 16) + (x) = 90 (x + 16) − (2x + 16) = 180 (x + 16) − (x) = 90

*asked on December 19, 2018* -
## algebra

Name the property of real numbers illustrated by the equation 2·(8·7)=(2·8)·7 answers are. Distributive property ,associative property multiplication, Communicative property multiplication, Associative property addition

*asked on February 23, 2014* -
## Chemistry

If the concentration of KCN at the equivalence point is 0.1M and the Ka for HCN is 6.2*10^-10 find the pH at the equivalence point. The reaction is between KOH and HCN From my understanding I have to do a stoichiometric calculation and then use the

*asked on September 28, 2016* -
## Algebra

The weight an object exerts on a scale varies directly with the mass of an object. If a bowling ball has a mass of 6 kg,the scale reads 54. a.write an equation for the relationship between weight and mass. b.If another object has a mass of 8 kg, what would

*asked on January 30, 2018* -
## Physics

Find the frequency of a wave whose period is 0.320s.

*asked on April 12, 2012* -
## Chemistry

How many grams of NaNO2 must be added to 1 liter of 1.00 M HNO2 solution in order to prepare a buffer solution with pH = 4.14? pH = 3.14? My work: ka = pH(buffer ratio) 4.5 * 10^-4 = 1.000*10^-4.14 (x M of base/1.00 M of acid) x = 6.21 6.21 M = (6.21

*asked on February 21, 2016* -
## Physics

A roller-coaster car with a mass of 500 kg starts at rest from point A, which is 46 m above the ground. At point B, it is 23 m above the ground.

*asked on February 2, 2011* -
## Math

Teaneck High had an enrollment of 11040 in 1985 and an enrollment of 12100 in year 1998. What is the predicted enrollment of Teaneck High in 2014 if we assume a linear model?

*asked on September 24, 2010* -
## math

I need to know if the following are independent dependent or inconsistent, y=-3x+19 y=2x-1 y=-4x-7 y=3x

*asked on November 17, 2008* -
## Algebra

Can you please help me solve r1/r2 = sqrt(M2/M1)for M1. My answer: M1=M2r2^2/r1^2 Is this correct?

*asked on January 28, 2015* -
## Algebra

please help me with this question and check my answers. Solve the problem. A rectangle with width 2x + 5 inches has an area of 2x4 + 9x3 - 12x2 - 79x - 60 square inches. Write a polynomial that represents its length. ( I don't know how to solve this

*asked on October 15, 2007* -
## Biology (muscle response)

Suppose you are asleep and the doorbell rings. You stumble to your feet and move toward the door, open it and speek with your visitor. Think of the many changes occurring in your body as you awaken and respond. How does the three types of muscle tissue

*asked on August 14, 2010* -
## chemistry

What volume of 0.406 M KOH is required to completely react with 18.50 mL of 0.287 M H2SO4?

*asked on February 22, 2011* -
## chemistry

on my selected thermodynamic data i cant find delta H for SiCl4(L) (i can solve the reaction i just cant figure out what SiCl4(L) is.

*asked on May 14, 2012* -
## Math

At the mall, Leona bought a T-shirt and a book for a total of $28. The book cost $12. How much did the T-shirt cost? What is the unknown information? Let x represent the unknown information. Write an addition equation that models the problem Solve the

*asked on September 18, 2019* -
## Calculus!!!

A piece of wire 28 m long is cut into two pieces. One piece is bent into a square and the other is bent into a circle. (a) How much wire should be used for the square in order to maximize the total area? (b) How much wire should be used for the square in

*asked on November 5, 2013* -
## Algebra

32.0=5.5x10^2(1/T)+14.2 Solve for T I am confused about what the first step would be to solving for T. Would I divide 5.5x10^2(1/T) and move it to the left side? Please help.

*asked on January 28, 2015* -
## math

please help! (sqrt3)cosx + sin2x = 0

*asked on September 23, 2019* -
## Geometry

Triangle STR is congruent to triangle XYZ, TR= 14c - 13, and YZ = 10c - 1, Find c and TR

*asked on July 23, 2018* -
## Trigonometry

Find cotangent theta given that cosecant theta equals -3.5891420 and theta is in the third quadrant. I was using the trig identity 1+cot^2theta=csc^2theta I wanted to isolate cotangent so I plugged in 1/sin (-3.5891420) and then squared my answer. I then

*asked on February 9, 2015* -
## algebra

Show all steps, combine like terms what is a simple form of the expression-3(-4y+3)+7y

*asked on February 23, 2014* -
## Geometry

I;m so lost with these questiona. Any help will be appreciated. 1. Find the area of a square if one side measures 27 centimeters. 2. Exactly how many cubic inches of air can a fully inflated basketball hold if its radius is 4.2 inches? Use Pi 3. How many

*asked on July 21, 2010* -
## Algebra 2

Which of the following equations represents the line that is parallel to the line y=5x+2 and that passes through the point (1,-3)?

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

32.0=5.5x10^2(1/T)+14.2 Solve for T I am confused about what the first step would be to solving for T. Would I divide 5.5x10^2(1/T) and move it to the left side? Please help.

*asked on January 28, 2015* -
## physics

A 5.0 ball is initially sitting at rest on top of a 41 m high hill. The ball is pushed with a force of 25 N for 3.0 s toward the edge of a hill. Upon reaching the edge, the ball is allowed to roll down the hill where it reaches the flat ground. To the

*asked on May 30, 2013* -
## math (linear programing problem)

Please help this question is from my unit on linear programing and I'm having trouble completing it. A company manufactures bicycles and tricycles. The total number of frames the company manufactures cannot exceed 80 per month. It takes the company 1 hour

*asked on November 16, 2010* -
## AP Physics

An 18.0 kg box is released on a 35.0° incline and accelerates down the incline at 0.269 m/s2. Find the friction force impeding its motion. How large is the coefficient of friction?

*asked on November 14, 2010* -
## Chemistry

Can you please help me solve r1/r2 = sqrt(M2/M1)for M1. My answer: M1=M2r2^2/r1^2 Is this correct?

*asked on January 28, 2015* -
## chemistry

How many grams of sodium hydroxide are required to prepare 500 mL of 0.500 M NaOH?

*asked on February 22, 2011* -
## math

which of the following represents a change from 32 to 40? a- an increase of 20% b- an increase of 25% c- an increase of 8% d- a decrease of 20% i don't want to know the answer to the question i would just like to know how to solve it. please help! thank

*asked on August 11, 2008* -
## Math

How many 2's must be multiplied together for the product to be a number between 100 and 200?

*asked on September 11, 2016* -
## algebra 2

two resistors are connected in parallel. their resistances are 8 ohms and 17ohms. what is the resistance of the combonation.

*asked on May 27, 2013* -
## Math

Can 252/1663 be simplified? If it can be simplified, what is the new simplified fraction?

*asked on November 22, 2010* -
## physics

A daredevil leaves the end of a ramp with a speed of 32.0 m/s if his speed is 29.8 m/s when he reaches the peak of the path, what is the maximum height that he reaches? how do i do thiss?

*asked on October 23, 2010* -
## Math

Bart and Bethany play a game. They each roll a regular 6-sided die labeled 1to 6. Use an outcome table to show all possible outcomes: (2 marks) is the total number of outcomes 12?

*asked on November 23, 2016* -
## physics

An oven is plugged into a 120 V electrical outlet and "cooks" the food by using a 144 ohm resistor light bulb that converts electrical energy to both light and heat energy. If the light bulb converts 75% of the electrical energy to thermal energy, and the

*asked on May 30, 2013* -
## Pre-Calc (Follow-up with Bob Pursley)

For the below problem, I solved it as you suggested and got k=.0486 When I did 300,000 = 122,000e^.0486t I got about 18.5 years for when the sewer system would need to be updated. Next, for how many people will the new system have to accommodate for the

*asked on January 10, 2010* -
## Math

What are the like terms in the exprression 3ac = ab - ac = 2ab? Explain. Simplify the expression. Show your work.

*asked on September 2, 2008* -
## Algebra

Solve the problem. A rectangle with width 2x + 5 inches has an area of 2x4 + 9x3 - 12x2 - 79x - 60 square inches. Write a polynomial that represents its length. I got x^3+2x^2-11x-12 inches. is this correct? I used long division.

*asked on October 15, 2007* -
## Science-Chemistry

Can you please help me solve r1/r2 = sqrt(M2/M1)for M1. My answer: M1=M2r2^2/r1^2 Is this correct?

*asked on January 28, 2015* -
## algebra 2

if a rock is dropped from the top of a 200 ft building, solve for the time it takes for it to hit the ground. (when h=0) hint-initial velocity when dropped is 0

*asked on May 26, 2013* -
## math 11

Please help this question is from my unit on linear programing and I'm having trouble completing it. A company manufactures bicycles and tricycles. The total number of frames the company manufactures cannot exceed 80 per month. It takes the company 1 hour

*asked on November 16, 2010* -
## physics

Find the height from which you would have to drop a ball so that it would have a speed of 6.4 m/s just before it hits the ground.

*asked on October 23, 2010* -
## Chemistry

The volume of the nitrogen gas is 125ml atmospheric pressure is 763mm Hg Water temperature is 24 degrees Celcius. The water level inside the eudiometer is the same as the level of water in the beaker. Calculate the pressure of the dry nitrogen gas.

*asked on April 9, 2015* -
## Math

Jason Printing has $85,000 to invest. They can invest in Wilder Revenue at 10% compounded semiannually or at Cheapskate Investments at 9.8% compounded monthly. a) Calculate the two APYs and compare them to determine your answer. Make sure to distinguish

*asked on April 15, 2014* -
## chemistry

EXTRA CREDIT QUESTION(this is like kinda really hard for me at the moment i got the first one but the others not so much) The city of Celina was ordered by the Ohio EPA in 2003 to resolve its MCL (maximum contaminant level) violations of its drinking

*asked on April 26, 2012* -
## Chemistry-Help Dr. Bob222

If a weak acid has a dissociation constant of 6.4 x 10^-6, what is the pH of a solution of this acid in a 0.10 molar concentration? I still don't understand the equation you gave me. My textbook doesn't break it down like this, so I'm confused as to where

*asked on December 14, 2010* -
## Math coin riddle need help please

I have 56 coins consisting of nickels and quarters. The total value of the coins is $5.60. How many of each coin do I have? Algebra to the rescue... NN is number of nickles ND is the number of quarters. NN*.05 + ND*.25=$5.60 but NN + ND=56 two equations,

*asked on August 31, 2005* -
## Chem

If 25.0 cm3 of 0.50M sulfuric acid reacted with exactly 12.5 cm3 of sodium hydroxide, calculate the concentration of the alkali. I first balanced the chemical equation between sulfuric acid and sodium hydroxide. H2SO4 + 2NaOH --> 2H2O + Na2SO4 I converted

*asked on September 8, 2017* -
## Physics

Two tuning forks are struck at the same time; one with a pitch of 410Hz one a frequency of 500Hz. How many pitches do you hear and what are the frequencies?

*asked on May 20, 2015* -
## chemistry

A reaction has ÄH = -378 kJ and ÄS = -37 J/K. Calculate ÄG at 25°C to confirm that the reaction is spontaneous. in kJ

*asked on May 15, 2012* -
## physics

A daredevil leaves the end of a ramp with a speed of 32.0 m/s if his speed is 29.8 m/s when he reaches the peak of the path, what is the maximum height that he reaches? how do i do thiss?

*asked on October 23, 2010* -
## Social Studies

I need a table about Silver mining rise during the last five years. PLEASE post me where I can find a DECENT one. Thanks Maddy It looks as if what you need to do is learn how to conduct thorough and effective searches for yourself. That's what research is.

*asked on May 11, 2007* -
## Biochemistry

An enzyme sample contains 24 mg protein per mL. Twenty µL of this sample in a standard incubation volume of 0.1 mL catalysed the conversion of substrate X to product Y at a rate of 1.6 nmol per minute. Calculate the velocity in terms of: a) µmol per

*asked on October 3, 2018* -
## Calculus

find the intervals on which f is increasing and decreasing f(x)=(x-2)/(X^2-x+1)^2 I found the derivative a got a whole mess of things: ((x^2-x+1)^2-2(x^2-x+1)(2x-1)(x-2))/(x^2-x+1)^4 Do I have to use the quadratic formula to solve for the vertices to find

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

i need help with more questions in the packet heres my question the poisonous gas hydrogen sulfide, H2S, can be neutralized with a base such as sodium hydroxide, NaOH. THE unbalanced equation for this reaction follows: NaOH(aq)+H2S(g)→Na2S(aq)+H2O(l) a

*asked on January 12, 2015* -
## statistics

How do you calculate the degrees of freedom for unequal sample sizes and unequal variance (independent t test)

*asked on October 6, 2012* -
## Square roots

The diagonal of a square has length square root 2 X s, where s is the length of a side of the square. What is the length of the diagonal in a square with sides that are 13 cm? Round your answer to the nearest tenth.

*asked on March 7, 2012* -
## chemistry

What is the concentration of HCl in a 250.0 mL sample of hydrochloric acid if 15.5 mL of 0.0100 M NaOH is needed to react with all the HCl?

*asked on February 22, 2011* -
## 1st grade

Is this sentence correct Breakfast Is Served Between 6:30 AM & 10:30 AM

*asked on March 13, 2009* -
## pre- algebra

Use the digits 1-9 in order. Insert operation signs and grouping symols to get a value of 100.

*asked on September 8, 2008* -
## Math

What are the like terms in this expression. 3ac + ab - ac + 2ab? Explain please?

*asked on September 1, 2008* -
## History

What is the best ways to organize a dbq and a thematic essay for the AP US Test?

*asked on March 9, 2008* -
## SOSE

Why should we ban people from having non native animals as pets (Australia)

*asked on February 1, 2008* -
## Chemistry

Prepare 30mL of a stock KI soln by mixing 10.0mL of the 0.03M KI in 0.2M KNO3 with 20.0mL of the .2M KNO3 Determine the concentration of the iodide ion. What does it mean by the 0.03M KI in 0.2M KNO3? Is this just bad wording of the question? Am I just

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

Graph y=2csc(x-π) New period that I solve for 0

*asked on October 11, 2015* -
## chemistry

i have a homework packet that i am struggling with can you please help me my first question is i have to finish the following equation to balance it out my question is 3Fe3O4+blankAl→blankAl2O3+blankFe now i tried and i got 3Fe3O4+2A=2Al2O3+2Fe i don't

*asked on January 12, 2015* -
## Math

Jason Printing has $85,000 to invest. They can invest in Wilder Revenue at 10% compounded semiannually or at Cheapskate Investments at 9.8% compounded monthly. a. Calculate the two APYs and compare them to determine your answer. Make sure to distinguish

*asked on April 14, 2014* -
## Predicate and subjects

1. The smell of cooking is delicious to the hungry camper. 2. A good fire is difficult to build. looking for simple subject and predicate 1, smell. Predicate. Camper subject 2. Fire subject. Build predicate

*asked on September 30, 2012* -
## Chemistry

I am having trouble answering this. please help! Q: Cereol is a newly discovered compound in corn flakes. A biologist suspects that it increases mental ability. She is making a solution to test on rats. First she makes a stock solution. She discovers that

*asked on March 31, 2012* -
## 6th grade

There are 3 parades on Cable Tv in the morning, 2 in the afternoon and 4 at night. How Many different combinations of parades can Ty watch?

*asked on November 4, 2010* -
## Math

-5+r=2r+3 what does r equal

*asked on November 2, 2010* -
## Chem

If 15.0 cm3 of 2M hydrochloric acid reacted exactly with 40.0 cm3 of potassium hydroxide. Calculate the concentration of the alkali I got the answer of .75M for KOH I went from cm^3 of HCl to L to mols then mols of KOH then to molarity of KOH. Is this

*asked on September 8, 2017* -
## PreCalc

Sqrt of 9sin^2x Is the answer |3sinx|? Is the three included in the absolute value sign? My teacher is very picky and I need to fully understand this concept. Thank you.

*asked on October 16, 2015* -
## science

i need help with a packet that im struggling with my questions are write the total number of atoms present for the following questions: a. 4SO2 now i tried and got 8O'S and 1S b. 8O2 i tried and got 16 all together c. 3Al2(SO4)3 i tried and got 6Al, 3S,

*asked on January 12, 2015* -
## Math- Precalculus

Write the expression as the sine, cosine, tangent of an angle (in radians.) (tan(pi/5)-tan(pi/3))/(1+tan(pi/5)tan(pi/3))

*asked on May 20, 2013* -
## Chemistry-pH problem

If a weak acid has a dissociation constant of 6.4 x 10(-6), what is the pH of a solution of this acid in 0.10 molar concentration?

*asked on December 13, 2010* -
## Chemistry-Confused by titration!!

If a 28 mLs of a 0.25 molar NaOH solution is used to titrate 14 mLs of a nitric acid to its phenolphthalein endpoint, what is the molar concentration of the acid?

*asked on December 13, 2010* -
## math11

I have several questions similar to this one and was wondering if you could walk me through this one. I'm totally lost on how to do it. Paramecia reproduce by splitting in two. In a laboratory flask, a colony of paramecia had an initial population of 500.

*asked on October 19, 2010* -
## pre-calc

The city planners of bakersfield, CA are studying the current and future needs of the city. The sewage system they have in place now can support 300,000 residents. The current population of the city is 180,000, up from 122,000 eight years ago. Assuming

*asked on January 8, 2010* -
## Chemistry

A student prepares a soln that is initally 0.006M Pb2+ and 0.00450M I-. This soln is placed into a 1.00cm wide cuvet and inserted into the spectrometer producing as abosrbance reading of 0.430 at a wavelength of 456nm. What is the equilibrium concentration

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

Factor: x^4(4) (2x+1)^3 (2x)+(2x+1)^4 (4x^3) Please help! I cannot figure out how to go about this problem

*asked on August 15, 2015* -
## physics

I need some help with determining the equation for this problem. "The block of mass m is released from rest on the frictionless incline. After sliding a certain distance, it compresses a spring and comes to rest at a distance of y beneath its original

*asked on December 14, 2014* -
## PreCalc

stacey is standing 5 miles west of the control tower at an airport. A plane took off traveling directly north of the control tower at a rate of 180 mph along the ground at a constant angle of 15 degrees. A)after 12 minutes, what is the angel between Stacey

*asked on February 9, 2014* -
## chemistry

Calculate the volkume of 0.750 M KNO3 that contains 17.0 grams of KNO3?

*asked on February 22, 2011* -
## Physics

Compare the gravitational force on an 11 kg mass at the surface of the Earth (with radius 6.3 X 10^6 m and mass 6 X 10^24 kg) with that on the surface of the Moon (with mass 1/81.3 ME and radius 0.27 RE). What is the force on the Earth? What is the force

*asked on February 20, 2011* -
## Physics

A hypothesis says the upper limit in frequency a human ear can hear can be determined by the diameter of the eardrum, which should have approximately the same diameter as the wavelength at the upper limit. Using the hypothesis what would be the radius of

*asked on February 21, 2010* -
## math

solve: perimenter of triangle perimeter is 12 meters determine values x, x+1, and x+2 x(x+1)+(x+2)=12

*asked on November 5, 2008*

## Pages

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