Saturday

February 6, 2016
Total # Posts: 3,476

**Discrete Math**

Let f : R R→Z be the closed binary operation defined by f (a, b) _ _a + b_. (a) Is f commutative? (b) Is f associative? (c) Does f have an identity element?
*May 8, 2013*

**Math**

Is 72.98 = 72.980 my answer is true.. Is it correct?
*May 7, 2013*

**Chemistry**

Assuming equal concentrations, rank these aqueous solutions by their freezing point: low to high NH4Cl, Sn(ClO3)4, Na2SO4, and AlBr3.
*May 4, 2013*

**chemistry**

find the molar solubility of zinc carbonate if its ksp=1.5x10^-10. (at 298K)
*May 4, 2013*

**math**

If the length of a rectangle is 4 more than 3 times the width, and the perimeter is 32 meters, what are its dimensions? Please enter your answer as two numbers without the units, separated by a comma.
*May 1, 2013*

**statistics**

a quiz consists of 30 true or false questions. if the student guesses on each question, what is the standard deviation of the number of correct answers
*April 29, 2013*

**Physics**

A ceiling fan starting from rest reaches an angular velocity of 30 rev/sec in 5 sec. What is the angular displacement of the fan during these 5 sec? Can you show me the steps need to figure this question out? Thanks!
*April 24, 2013*

**Physics**

A drawbridge with a weight of 5000 N is supported by a hinge and rope and is in static equilibrium. The length of the drawbridge is 5 m and the rope is attached to the draw bridge a distance of 4 m from the hinge. What is the tension force rope provides? Can you show me steps ...
*April 24, 2013*

**math**

I'm sorry, but I don't think this is possible since 999 + 999 = 1098 (even the sum of the largest possible three-digit numbers do not give us a large enough total. 104 x 162 = 16848 (not sure if you wanted a "product?" I found this by trial and error with a ...
*April 22, 2013*

**math**

there are 9 candidates running for 3 seats....how many different election results are possible
*April 22, 2013*

**Calculus**

Find the exact area below the curve y=x^3(4-x)and above the x-axis
*April 21, 2013*

**Chemistry**

Consider the dissolution of CaCl2. CaCl2(s) Ca2+(aq) + 2 Cl-(aq) ÄH = -81.5 kJ A 10.4-g sample of CaCl2 is dissolved in 102 g of water, with both substances at 25.0°C. Calculate the final temperature of the solution assuming no heat lost to the surroundings and ...
*April 18, 2013*

**Java programming**

can u give me some example of withdrawal money program using array to store ten information of user. including the attributes: (i) Name of the depositor (ii) Account number (iii) Type of account (iv) Balance amount And the methods: (i) Deposit (ii) Withdraw (iii) Display the ...
*April 18, 2013*

**math**

Your store’s average basket (transaction) size for the month of March was $11.50 and you believe the average basket size will remain the same for your store in April. One of your hourly employees had an average basket size of $9.00 for the month of March and averaged 125 ...
*April 18, 2013*

**math**

not sure confused
*April 13, 2013*

**math**

Suppose A is the set of students registered at the University of Calgary, and C is the set of courses currently being offered at the University of Calgary. Under what conditions is each of the following a function? a) {(a, c) | a’s first class each week is in c} b) {(a, c...
*April 13, 2013*

**English**

Having problems with a introductory sentence. Its a essay on dying and living. I wrote a question to start my intro. Sentence. Or I wrote The professor died in 1974 of Cancer. Someone please let me know if I started out right. Please
*April 12, 2013*

**social science statistics**

a professor was curious to whether the students in a very large class she was teaching who turned in their first scored differently from the overall mean on the test.The overall mean score on the test was 75 with a standard deviation of 10;the score were approximately normally...
*April 9, 2013*

**english**

the couple ordered ___ for hors d'oeuvres at the wedding a)pumpkin pie b)cake c)soup d)stuffed mushrooms?
*April 4, 2013*

**algebra**

If a pendulum is 30 feet long what is the period of the pendulum in seconds with function l = 0.81t^2
*April 4, 2013*

**MATH please help**

An object at rest begins moving horizontally on the x-axis, starting at position x(t) = 0 feet at time t = 0 seconds.Suppose, after exactly 2 seconds we measure the position of the object to be 3 feet to the right of the origin AND measure the object to be moving to the ...
*April 3, 2013*

**Science**

grapes biotic
*April 2, 2013*

**Math**

1. Number sense. Could the frozen yogurt survey help restaurants choose flavors of frozen yogurt? Explain. 2. Give an example of a topic for a survey question where the results for the answers could be similar.
*April 1, 2013*

**physics**

Two racquetballs, each having a mass of 200 g, are placed in a glass jar as shown in in the figure below. Their centers lie on a straight line that makes a 45° angle with the horizontal.
*March 31, 2013*

**calculus**

A potter forms a piece of clay into a right circular cylinder. As she rolls it, the height h of the cylinder increases and the radius r decreases. Assume that no clay is lost in the process. Suppose the height of the cylinder is increasing by 0.5 centimeters per second. What ...
*March 31, 2013*

**Math**

What is greater -19 or -17?
*March 25, 2013*

**algebra**

In 2000, the average family net worth was $360,000 and there were about 7.7x10^7 families. Calculate the total family net worth in 2000.
*March 20, 2013*

**Math**

Which shows 18.64 rounded to the nearest tenth? My answer is 18.6 is this correct
*March 18, 2013*

**Chem**

What is the specific heat in J/g Celsius for a metal sample with a mass 95.6 g which absorbs 841 J of energy when it's temperature increases from 30.0 degrees Celsius to 98.0 degrees Celsius?
*March 18, 2013*

**Chem**

What is the specific heat in J/g Celsius for a metal sample with a mass 95.6 g which absorbs 841 J of energy when it's temperature increases from 30.0 degrees Celsius to 98.0 degrees Celsius?
*March 18, 2013*

**Chem**

What is the specific heat in J/g Celsius for a metal sample with a mass 95.6 g which absorbs 841 J of energy when it's temperature increases from 30.0 degrees Celsius to 98.0 degrees Celsius?
*March 17, 2013*

**maths**

When conducting an inferential statistical analysis, and applying a conventional “critical p- value” of .05, the odds of making a Type I Error and “rejecting a true Null Hypothesis” is…?
*March 17, 2013*

**AP Chemistry**

Ohhhh, that makes sense! Thanks!
*March 16, 2013*

**AP Chemistry**

A biochemist prepares a lactic acid-lactate buffer by mixing 225 mL of 0.85M lactic acid with a Ka=1.38*10^-4 with 435mL of 0.68M sodium lactate. What is the buffer pH? I know I have to use the equilibrium constant expression, but I'm pretty lost from there. Can someone ...
*March 16, 2013*

**math**

sonya spent three eighth of her money and then had $15 left. how much money did she originally have
*March 16, 2013*

**Math**

0.9 x 2 or 2 + 0.9
*March 14, 2013*

**Math**

Which is greater 0.9 x 2 or 2 + 9? My answer is 0.9 + 2 is greater because it equals 2.9 and 0.9 x 2 = 1.8.. Is this correct?
*March 14, 2013*

**Chemistry**

thnk u so much
*March 14, 2013*

**cHEM**

i got 114.5 is this right?
*March 14, 2013*

**cHEM**

It is found that 1.431 g of element X contains 7.509 × 1021 atoms. The atomic mass of X is?
*March 14, 2013*

**Math/230**

A 350 word response how to compute probabilities using z score
*March 14, 2013*

**Chemistry **

What is the change in enthalpy when 17.0 g of liquid mercury is heated by 31°C?
*March 12, 2013*

**Physics**

A force is applied to a door at an angle of 56.8° and 0.34 m from the hinge. a) What force produces a torque with a magnitude of 2.18 N·m? b) How large is the maximum torque this force can exert?
*March 12, 2013*

**english**

what's an example of an appostion in the book Miracle Worker?
*March 10, 2013*

**algebra**

an investment of $50,000 was made by a busines club. the investment was split into three parts and lasted for one year.the first part of the investment earned 8% interest, the second 6%, and the third 9%. total interest from the investments was $3960. the interest from the ...
*March 6, 2013*

**Physics**

A car is travelling along a highway with a speed of 25 m/s when the driver sees an obstruction 1.80*10^2 m directly ahead. It takes the driver 0.80s to react and begin braking. a) How far does the car travel before it begins to slow down? b) How long will it take the car to ...
*March 4, 2013*

**Physics**

In a target shooting game, wooden blocks are thrown into the air and shot in flight. A block of 0.8kg has a speed of 10 m/s at the top of its trajectory when it is hit by a bullet from below at an angel 60° from horizontal. The mass of the bullet is 5.0 g and its speed is ...
*March 4, 2013*

**Physics**

In a target shooting game, wooden blocks are thrown into the air and shot in flight. A block of 0.8kg has a speed of 10 m/s at the top of its trajectory when it is hit by a bullet from below at an angel 60° from horizontal. The mass of the bullet is 5.0 g and its speed is ...
*March 4, 2013*

**Calculus**

Thank you
*March 3, 2013*

**Calculus**

Find the tangent line approximation for sqrt(3+x) near x=0.
*March 3, 2013*

**Calculus**

Find the derivatives of the function f(t)=cosh^2(4t)-sinh^2(4t). Simplify your answer completely.
*March 3, 2013*

**Chemistry**

What is the complete and net ionic equations for: Cu+Zn+2HCl--> ZnCl2+Cu+h2
*March 1, 2013*

**Math**

A garden has 10 equal rows. Two rows have beans, 1 row has lettuce, 3 rows have squash, and 4 rows have tomatoes. What part of the garden is beans? My answer is 0.2, or 2/10. Is this correct
*February 27, 2013*

**fractions**

Shouldn't it be stated as 3,4 and 6 go into 12 evenly. 1/3= 4/12 1/4= 3/12 1/6= 2/12 2/12+3/12+4/12= 9/12. Reduce 9/12 to 3/4. 4/4-3/4= 1/4 not colored
*February 26, 2013*

**math**

if n= 44, what is the value of 75-n+ 6?
*February 25, 2013*

**Calculus**

show that e^-x ¡Ö 1-x near x=0
*February 25, 2013*

**American History *URGENT***

so i have some multiple choice questions that i am confused on. *PLEASE TAKE THE TIME TO READ* i know it's alot, but it would really help me out so much! this is due in the morning! I had a total of 122 questions, but got stuck on a few. on the first one I was able to ...
*February 24, 2013*

**math**

i don't know
*February 23, 2013*

**American History**

The English civil war affected the american colonies in which of the following ways: a.) With england convulsed in civil war, the mother country for a time failed to provide military protection to the colonies b.) Several colonies began to discuss forming a confederation, but ...
*February 21, 2013*

**American History**

The English civil war affected the american colonies in which of the following ways: a.) With england convulsed in civil war, the mother country for a time failed to provide military protection to the colonies b.) Several colonies began to discuss forming a confederation, but ...
*February 21, 2013*

**Organic Chem**

What is the major product obtained from the dehydration of 3,5-dimethylchyclohexanol?
*February 20, 2013*

**math problem**

Both Al and Bill must run from their positions to point C and then on to D. They start at the same time and each runs at a constant speed . When Bill gets to point C Al has passed there and is 40 yards towards D. If point D is ____ yards from C, they will arrive at point D at ...
*February 19, 2013*

**Physics**

Masses 15 kg and 8 kg are connected by a light string that passes over a friction-less pulley with the 15 kg mass on a table and the 8 kg mass hanging off the edge. The acceleration of gravity is 9.8 m/s2. If the 15 kg mass, initially held at rest on the table, is released and...
*February 19, 2013*

**calc **

the base of s is a elliptical region with boudary cuvrve 16x^2 +16y^2 =4. cross sections perpandicular to the x axis are isosceles right triangles with hypotenuse in the base. find the volume of s
*February 19, 2013*

**Calculus**

find the derivative. f(á)=ln(siná)
*February 18, 2013*

**Math**

If $32,500.00 is invested at 6.4% for 30 years, what is the future value if the interest is compounded continuously?
*February 16, 2013*

**Math**

What is the simplest form of 1 and 2/6 (1 2/6) My answer is 1/3.. Is it correct?
*February 13, 2013*

**Math problem**

-A clock is divided equally into 60 units. Each unit forms an angle of 6^0.The hour hand moves 1 of these units for every 12 units that the minute hand moves. it move 2 of these units for every 24 units for the minute hand,ete.At 6 o'clock the hour hand and the minute hand...
*February 12, 2013*

**CIS 115**

You have been asked to design a program that will allow a teacher to calculate the percentage and the final grade for students in a class. The program will prompt the teacher to enter the student’s first and last name and the number of points the student received. The ...
*February 12, 2013*

**•Chemistry **

How many mole are present in 2.45x10^23 molecules of CH4? ( CH4= 16.05)
*February 12, 2013*

**chemistry**

I'm looking for an answer to this question
*February 11, 2013*

**calculus**

Find the Derivative y=(t^2+3)e^t
*February 11, 2013*

**Chemistry Help**

The ΔHvap of a certain compound is 34.68 kJ·mol–1 and its ΔSvap is 93.60 J·mol–1·K–1. What it the boiling point of this compound?
*February 10, 2013*

**Math**

My answer is 3/8 is it right? 3/4-3/8= 6/8-3/8= 3/8
*February 6, 2013*

**Math**

At the dance, Lyndi and Josh danced 3/4 hour without stopping. This is 3/8 hour more rhan Kecia and Les danced. How long did Kecia and Les danced? Show your work..
*February 6, 2013*

**Math**

At the dance, Lyndi and Josh danced 3/4 hour without stopping. This is 3/4 hour more than Kecia and Les danced. How long did Kecia and Les dane? Show your work.,
*February 6, 2013*

**Calculus **

find the derivatives of the given functions. g(t)=sqrt t(1+t)/t^2 the sqrt is just over t.
*February 4, 2013*

**English**

In persuasive writing, it is important to
*February 3, 2013*

**Physics**

A wooden block of mass m = 9 kg starts from rest on an inclined plane sloped at an angle θ from the horizontal. The block is originally located 5m from the bottom of the plane. If the block, undergoing constant acceleration down the ramp, slides to the bottom in t = 2 s, ...
*February 3, 2013*

**physics**

How long does it take light to travel through a 3.3 mm-thick piece of window glass?
*January 30, 2013*

**Math**

Thank You That Is What I Got Also, But The Workbook Said x equaled 3
*January 30, 2013*

**Math**

5x-6 = 2x+12 It says x=3 but I don't understand how, can you you explain the steps for me?
*January 30, 2013*

**physics**

If two charges are a distance R apart from eachother and their force is F, what will the force be if they are moved apart to a distance of 2R?
*January 30, 2013*

**calculus**

Find a value c in the interval [0,2] such that f(c)is equal to the average value.
*January 30, 2013*

**calculus**

The base of a certain solid is the triangle with vertices at (-14,7), (7,7), and the origin. Cross-sections perpendicular to the y-axis are squares. What is the volume?
*January 29, 2013*

**Calculus**

a swimming pool has the shape of the ellipse given by (x^2)/3600 + (y^2)/1600 = 1 The cross sections perpendicular to the ground and parallel to the y-axis are squares. Find the total volume of the pool.
*January 29, 2013*

**Math**

You are playing Guess you card with (3) other players. Here is wha you see: Andy has the cars 1,5, and 7 Belle has the cards 5,4, and 7 Carol has the cards 2,4, and 6 Andy draws the question card, " do you see two or more players whose cards sum to the same value? He ...
*January 28, 2013*

**Calculus**

Estimate the following limit by substituting smaller and smaller values of h. lim 8^h-1/h h->0
*January 27, 2013*

**physicss**

A spring scale being used to measure the weight of an object reads 17.1 N when it is used on earth. The spring stretches 4.40 cm under the load. The same object is weighed on the moon, where gravitational acceleration is 1 /6 g. Find the reading of the spring scale on the moon...
*January 25, 2013*

**PHYSICS!!!!HELP PLEASE**

A spring scale being used to measure the weight of an object reads 17.1 N when it is used on earth. The spring stretches 4.40 cm under the load. The same object is weighed on the moon, where gravitational acceleration is 1 /6 g. Find the reading of the spring scale on the moon...
*January 25, 2013*

**PHYSICS *_* HELP PLEASE**

A spring scale being used to measure the weight of an object reads 17.1 N when it is used on earth. The spring stretches 4.40 cm under the load. The same object is weighed on the moon, where gravitational acceleration is 1 6 g. Find the reading of the spring scale on the moon...
*January 25, 2013*

**Physics**

A spring scale being used to measure the weight of an object reads 17.1 N when it is used on earth. The spring stretches 4.40 cm under the load. The same object is weighed on the moon, where gravitational acceleration is 1/6g Find the reading of the spring scale on the moon. ...
*January 24, 2013*

**Physics**

Find g at a point on earth where T = 2.249 s for a simple pendulum of length 1.250 m, undergoing small-amplitude oscillations. (Enter your answer to four significant figures.) CAN YOU PLEASE PROVIDE AN ANSWER WITH WORK . THANK YOU VERY MUCH!!!!!
*January 24, 2013*

**Physics**

A pendulum clock is accurate on earth, where the period of its pendulum is 1.00 s. (a) Find its period on the moon, where gravitational acceleration is 1.6 m/s2. (b) During a 2 h interval, what would be the elapsed time shown on the clock? CAN YOU PLEASE PROVIDE AN ANSWER WITH...
*January 24, 2013*

**Physics**

Find the length of a simple pendulum that completes 16.0 oscillations in 52.0 s. CAN YOU PLEASE EXPLAIN SPECIFICALLY , THANK YOU!
*January 24, 2013*

**Math **

Find the decibel intensity level at a rock concert if the intensity was measured at 3.98x10^-3
*January 24, 2013*

**Physics**

A spring scale being used to measure the weight of an object reads 17.1 N when it is used on earth. The spring stretches 4.40 cm under the load. The same object is weighed on the moon, where gravitational acceleration is 1 6 g. Find the reading of the spring scale on the moon...
*January 24, 2013*

**Physics**

A patio swing is suspended by two springs, each of which has a force constant of 415 N/m, equivalent to a single spring force constant of 830 N/m. Find the mass of a person sitting on the swing oscillating up and down at a frequency of 0.590 Hz. Please HELP!
*January 24, 2013*

**Calculus**

Find a solution to the equation if possible. Give the answer in exact form and in decimal form. 8=4sin(5x)
*January 24, 2013*

**Physics**

If a bullet was fired straight up at a speed of 30 m/s what would be the total time for it to return to its starting point?
*January 23, 2013*