Friday

April 18, 2014

April 18, 2014

Total # Posts: 171

**math**

Thank you so much

**math**

The sales goal for your store this week is $22,682. The sales goal for your store this week last year was $20,128. Your store has averaged 1775 transactions per week for the last four weeks. Assuming the number of transactions is consistent, what is the average basket size (tr...

**Physics**

A baby whale gets lost from his mother while swimming through a large underwater canyon. Frantically the baby whale yells for his mommy. 1.5 seconds later, the whale hears his yell's ECHO from the canyon wall. How far is it to the canyon wall? The speed of sound in water i...

**I need help (Physics)**

A 28 kg ball initially at rest rolls down a 159 m hill. When the ball reaches the bottom it is traveling at 31.3 m/s. How much energy is dissipated by friction on the ball?

**Math**

For what value of a, would the system have an infinite number of solutions? 2x-y=5 8x-47=2a A) 2 B) 4 C)5 D)10 E)20

**geometry**

THANK STEVE i HAVE THE ASNWER

**geometry**

IT DOESNT SAY STEVE

**geometry**

If A point K is the reflection of L (2,5) IN THE Y AXIS WHAT IS THE LENGTH OF KL

**bus-math**

Oakwood Plowing company purchased two new plows. In 170 days they must make a payment of $24,330.00 to pay for them. As of today they have $23,600 what rate of interest will be needed.

**Physics**

Three moles of an ideal monatomic gas are at a temperature of 396 K. Then 2438 J of heat is added to the gas, and 897 J of work is done on it. What is the final temperature of the gas?

**Physics**

A container holds 1.3 mol of gas. The total average kinetic energy of the gas molecules in the container is equal to the kinetic energy of a 6.6x10-3 kg bullet with a speed of 670 m/s. What is the Kelvin temperature of the gas?

**biology**

Imagine that you collected your data above, threw away the gel, and re-ran PCR again on the same samples, but using a different set of primers. How will the 2nd gel differ from the first since you're using a different set of primers?

**MATH**

(a) Transform the expression (x − a)^2 + y^2 = a^2 into polar coordinates. (b) Sketch the region R bounded by the curve given in part (a). (c) Use a double integral in polar coordinates to ﬁnd the area of the region R.

**physics**

The drawing shows a 25.1-kg crate that is initially at rest. Note that the view is one looking down on the top of the crate. Two forces, 1 and 2, are applied to the crate, and it begins to move. The coefficient of kinetic friction between the crate and the floor is μk = 0...

**algebra**

15. To travel a fixed distance, the number of gallons needed is inversely proportional to the miles per gallon rating P of the car that gets 42 miles per gallon (mpg) needs 33 gallons to travel the distance. a. Find an equation of variation N= b. A car that gets 77 mpg needs _...

**algebra**

((5w^2-16w+3)/(5w^2+24w-5))/((15w^2-8w+1)/(3w^2+14w-5))

**physics**

Two cars, A and B, are traveling in the same direction, although car A is 204 m behind car B. The speed of A is 22.9 m/s, and the speed of B is 18.6 m/s. How much time does it take for A to catch B?

**Physics**

A rifle that has been "sighted in" for a 94.6-meter target. If the muzzle speed of the bullet is v0 = 429 m/s, what are the two possible angles è1 and è2 between the rifle barrel and the horizontal such that the bullet will hit the target? One of these ...

**maths**

thank you

**maths**

A truck rolls down a hill subject to acceleration due to gravity and resistance (including air resistance, rolling friction, etc) and the distance si (metres) travelled after ti seconds is observed. Classical mechanics predicts that the distance travelled by the truck should b...

**math**

For every prime p consider all polynomials f(x) with integer coefficients from 1 to p and degree at most p−1, such that for all integers x the number f(2x)−f(x) is divisible by p. Find the sum of all primes p<1000 such that the number of such polynomials is stri...

**MATH hard problem...HELLPPPPPP**

Let S={1,2,3,…11} and T1,T2…,TN be distinct subsets of S such that |Ti∩Tj|≤2 for all values i≠j. What is the maximum possible value of N? clue: The empty set is a subset of every set. Thanks

**MATH Help please.....**

Let S={1,2,3,…11} and T1,T2…,TN be distinct subsets of S such that |Ti∩Tj|≤2 for all values i≠j. What is the maximum possible value of N? (The empty set is a subset of every set.)

**Physics**

i input your formula and false

**Physics..Elena or anybody please help**

0.881

**Physics..Elena or anybody please help**

I(mass=80 kg) sit down in the center of a trampoline and the surface sinks down by a distance of 10 cm when I reach equilibrium. How far above the ground in m must the trampoline be placed so that if I jump onto the trampoline from a height of 3 m above the surface of the tram...

**Math**

Thank you Steve.

**Math**

Having a problem writing an expanded number in notation in descending order. Ex. 92,563,174. I know the placements and the number but have a problem when it comes to write it. Can you please help. I would appreciate an example so much.

**Elements of Calculus**

I cant seem to figure this one out, please help. A company is manufacturing kayaks and can sell all that it manufactures. The revenue (in dollars) is given by R=750-(X^2/30) where the production output in 1 day is x kayaks. If production is increasing at 3 kayaks per day when ...

**Phyics**

In a solar water heater, energy from the Sun is gathered by water that circulates through tubes in a rooftop collector. The solar radiation enters the collector through a transparent cover and warms the water in the tubes; this water is pumped into a holding tank. Assume that ...

**Statistics**

Given a study of 9804 overweight or obese subjects with preexisting cardiovascular disease and/or type 2 diabetes. Subjects randomly assigned to subitramine (4906 subjects) or a placebo (4898 subjects) in a double-blind fashion. Primary outcome was observed in 561 subjects in ...

**math **

x+2/3x-6*x^2-3+2/x^2-x-6

**math**

75% of teenagers own cell phones and ofthose who own cell phones, 87% use text messaging. 1. What % of teens own cell phones AND text? 2. Among those who own cell phones and text, 15% send more than 200 texts a day, or more than 6,000 texts a month. What % of all teens own a c...

**physics**

A ray of light is incident at an angle of 20degrees to the normal on one face of an equilateral prism made in glass of refractive index 1.523. Find the total deviation produced.

**Chemistry**

Why did you need to know the density of the bleach solution? Why didn't you measure the density of h2o2 solution as well? Stoichiometry lab problem

**Physics**

To move a large crate across a rough floor, you push on it with a force F at an angle of 21° below the horizontal, as shown in the figure. Find the force necessary to start the crate moving, given that the mass of the crate is m = 29 kg and the coefficient of static fricti...

**Physics**

Thank you very much Elena for that and also for promptly answering my question on a timely manner!!!

**Physics**

You are pulling your little sister on her sled across an icy (frictionless) surface. When you exert a constant horizontal force of 114 N, the sled has an acceleration of 2.3 m/s2 If the sled has a mass of 7.6 kg, what is the mass of your little sister? I don't need the ans...

**physics**

Thank you!

**physics**

A light of ray is incident at an angle of 58degrees on the plane surface of a block of glass of refractive index 1.60. Some light is reflected on the other side of the normal at the same angle as the angle of incidence. Find: a.the angle between the light reflected from the su...

**physics/light reflection**

A light of ray is incident at an angle of 58degrees on the plane surface of a block of glass of refractive index 1.60. Some light is reflected on the other side of the normal at the same angle as the angle of incidence. Find: a.the angle between the light reflected from the su...

**algebra**

=12+24*6*2-17 =283

**Physics**

thank you!

**Physics**

The following four lenses are placed together in close contact. Find the focal length of the combination. Lens 1- F'= +200mm Lens 2- F'= -125mm Lens 3- F'= -400mm Lens 4- F'= +142.9mm

**Physics**

You are riding on a jet ski directed at an angle upstream on a river flowing with a speed of 2.8 m/s. If your velocity relative to the ground is 8.9 m/s at an angle of 26.0° upstream, what is the speed of the jet ski relative to the water? (Note: Angles are measured relati...

**Stats**

I ran this an an independent samples t-test. It is a t rest according to the professor, just want to make sure I have the right one. A researcher wanted to answer the following question: What is the difference in students' computer anxiety based on whether or not they own ...

**Physics**

1. A bullet of 0.0500 kg is fired into a block of wood. Knowing that the bullet left the gun with a muzzle velocity of 350. m/s, and the bullet penetrates .15 m into the block of wood, determine: a) The average force required to stop the bullet. b) The impulse exerted by the w...

**stsats**

A researcher wanted to answer the following question: What is the difference in students' computer anxiety based on whether or not they own computers? The researcher surveyed 92 undergraduate education students via an online survey. In the survey, the researcher asked a ye...

**Statistics**

I bemieve the t test is paired , want to make usre beofre I run the stats. A researcher wanted to answer the following question: What is the difference in students' computer anxiety based on whether or not they own computers? The researcher surveyed 92 undergraduate educat...

**math**

The sales goal for your store this week is $22,682. The sales goal for your store this week last year was $20,128. Your store has averaged 1775 transactions per week for the last four weeks. Assuming the number of transactions is consistent, what is the average basket size (tr...

**physics**

A proton that has a mass m and is moving at 250 m/s in the + direction undergoes a head-on elastic collision with a stationary oxygen nucleus of mass 16m. Find the velocities of the proton and the oxygen nucleus after the collision

**physics **

A proton that has a mass m and is moving at 250 m/s in the + direction undergoes a head-on elastic collision with a stationary oxygen nucleus of mass 16m. Find the velocities of the proton and the carbon nucleus after the collision

**physics **

A 2.0-kg ball moving at 10 m/s makes an off-center collision with a 3.0-kg ball that is initially at rest. After the collision, the 2.0-kg ball is deflected at an angle of 30° from its original direction of motion and the 3.0-kg ball is moving at 4.0 m/s. Find the speed of...

**physics **

A 2.0-kg ball moving at 10 m/s makes an off-center collision with a 3.0-kg ball that is initially at rest. After the collision, the 2.0-kg ball is deflected at an angle of 30° from its original direction of motion and the 3.0-kg ball is moving at 4.0 m/s. Find the speed of...

**PHYSICS **

Allegra's favorite ride at the Barrel-O-Fun Amusement Park is the Flying Umbrella, which is lifted by a hydraulic jack. The operator activates the ride by applying a forcce of 72 N to a 3.0-cm-wide cylindrical piston, which holds the 20000. N ride off the ground. What is t...

**PHYSICS **

A 5450-m^3 blimp circles Fenway Park duing the World Series, suspended in the earth's 1.21-kg/m^3 atmosphere. The density of the helium in the blimp is 0.178 kg/m^3. A) What is the buoyant force that suspends the blimp in the air? B) How does this buotant force compare to ...

**chemistry**

how many grams of CO are needed to react with an excess of Fe2O3 to produce 209.7gFe? Fe2O3(s) + 3CO(g) => 3CO2(g) + 2Fe(s)

**chemistry**

sorry. time is in minutes not seconds

**chemistry**

Suppose that you place exactly 100 bacteria into a flask containing nutrients for the bacteria and that you find the following data at 37 °C: TIme (s) number of bacteria 0 100 19 200 38 400 57 800 76 1600 what is the rate order? What is rate constant? how many bacteria wil...

**chemistry**

A certain reaction has an activation energy of 74.38 kJ/mol. At what Kelvin temperature will the reaction proceed 7.00 times faster than it did at 313 K?

**chemistry**

A certain reaction has an activation energy of 74.38 kJ/mol. At what Kelvin temperature will the reaction proceed 7.00 times faster than it did at 313 K?

**AP CHEMISTRY**

Someone please answer my question below in AP CHEMISTRY.

**AP CHEMISTRY**

thanx!!

**AP CHEMISTRY**

A)In a chemical reaction two gases combine to form a solid. What do you expect for the sign of ΔS? B) For which of the following processes does the entropy of the system increase? (Select all that apply.) -> alignment of iron filings in a magnetic field -> the melti...

**AP CHEMISTRY**

Calculate the solubility of LaF3 in grams per liter in the following solutions. (Ksp = 2. 10-19.) a) pure water Ans: .00182g/L b) 0.037 M KF solution c) 0.055 M LaCl3 solution NEED b&c PLEASE HELP

**AP CHEMISTRY**

THANX!!!

**AP CHEMISTRY**

SOMEONE PLEASE EXPLAIN AND ANSWER THIS QUESTION : Will Co(OH)2 precipitate from solution if the pH of a 0.034 M solution of Co(NO3)2 is adjusted to 9.45? (Ksp of Co(OH)2 is 1.3 10-15) Support your answer by calculating the ion product (Q) of the Co(OH)2 solution.

**AP CHEMISTRY**

Calculate the solubility of Mn(OH)2 in grams per liter when buffered at each of the following. a) pH 7.4 b) pH 9.2 c) pH 11.5 ALL IN GRAMS PER LITER. PLEASE HELP ME AND EXPLAIN

**AP Chemistry**

A buffer, consisting of H2PO4− and HPO42−, helps control the pH of physiological fluids. Many carbonated soft drinks also use this buffer system. What is the pH of a soft drink in which the major buffer ingredients are 7.20 g of NaH2PO4 and 4.90 g of Na2HPO4 per 35...

**calculus**

find max, min and saddle points of the give function f(x,y)=sin(x)+sin(y)+sin(x+y) 0<=x<=pi/4 0<=y<=pi/4 i have that dz/dx=cos(x)+cos(x+y) dz/dy=cos(y)+cos(x+y) and i set them equal to zero but im kinda confused on how to really solve that. i mean i got an answer b...

**AP CHEMISTRY**

i asked another question in my post below pleaseeeeeeeee answer it.. THANX!!!!!!!

**AP CHEMISTRY**

Write the formula for the following compound, being sure to use brackets to indicate the coordination sphere. A) potassium tetrabromo(ortho-phenanthroline)- cobaltate(III)

**AP CHEMISTRY**

thank u and next time i will show some work

**AP CHEMISTRY**

THANX. but did u guess 8.7 or did u calculate it? if so could u show howw???

**AP CHEMISTRY**

it says the titration of 0.145g of a weak acid with 0.100M NaOH as the titrant

**AP CHEMISTRY**

The following acid-base indicators are available to follow the titration. Which of them would be most appropriate for signaling the endpoint of the titration? EXPLAIN ------- COLOR CHANGE ------ INDICATOR <-> Acid form <-> Base Form <-> pH Transition Interva...

**AP CHEMISTRY**

The following acid-base indicators are available to follow the titration. Which of them would be most appropriate for signaling the endpoint of the titration? EXPLAIN ------- COLOR CHANGE ------ INDICATOR <-> Acid form <-> Base Form <-> pH Transition Interva...

**AP Chemistry**

Mlszwski???

**AP CHEMISTRY**

SOMEONE PLEASEEEEEEEEE ANSWER MY PROBLEM IN THE POST BELOW!!!!!!!!!!!!!!!!!!!!!!!!!!!

**AP CHEMISTRY**

THNX!!!!!!!!!!!!!!!!!!!!

**AP CHEMISTRY**

IS IT 0.1167 M ?????

**AP CHEMISTRY**

1) Calculate the molarity of a solution of sodium hydroxide, NaOH,if 23.64 mL of this solution is needed to neutralize 0.5632g of potassium hydrogen phthalate. 2) It is found that 24.68 mL of 0.1165M NaOH is needed to titrate 0.2931 g of an unknown acid to the phenolphthalein ...

**AP CHEMISTRY**

would the units be grams????

**AP CHEMISTRY**

THANX!!!!!!!!!!!!!!!!!!!!!!

**AP CHEMISTRY**

Calculate the equivalent mass of each of the following acids. a) HC2H3O2 b) KHCO3 c) H2SO3

**AP CHEM5**

answer my question beloww!!

**AP CHEM**

potassium tetrabromo(ortho-phenanthroline)- cobaltate(III)

**AP CHEM**

COuld u please answer this Ineed the formula for bis(bipyridyl)cadmium(II) chloride

**AP CHEM**

formula for bipyridyl

**Math Help Please**

Would someone please be kind enough to explain steps for this one. Thank you. If m and n are positive integers and m is 250% of n, what percent of m is 2n?

**AP CHEMISTRY**

A) At 800 K the equilibrium constant for I2(g) <=> 2 I(g) is Kc = 3.1 10-5. If an equilibrium mixture in a 10.0-L vessel contains 3.44*10-2 g of I(g), how many grams of I2 are in the mixture? answer is .060g B)For 2 SO2(g) + O2(g)<=> 2 SO3(g), Kp = 3.0*104 at 700 K...

**mathhh**

You select 8 cards randomly from a deck of 52 cards. What is the probability that all of the cards selected are face cards (i.e. jacks, queens, or kings)

**calculus **

find the integral of e^x/[(e^x-3)(e^x+4)] dx

**Physics**

You have 300 g of coffee at 55 degrees celcius. Coffee has the same specific heat as water. How much 10 degrees celcius water do you need to add in order to reduce the coffee's temperature to a more bearable 49 degrees celcius?

**Physics**

You have 300 g of coffee at 55 degrees celcius. Coffee has the same specific heat as water. How much 10 degrees celcius water do you need to add in order to reduce the coffee's temperature to a more bearable 49 degrees celcius?

**physics**

You have arrived at a new planet and put your starship into a circular orbit at a height above the surface that is equal to two times the radius of the planet. Your speed is 4300 m/s and it takes 7 hours and 18 minutes to complete an orbit. a. What is the radius of the planet?...

**math**

A perfect minor wholetone is a frequency rtio of 10:9. A perfect major wholetone is a frequency ratio of 9:8. Are these noticeably different from an equal temper wholetone? (200 cents)

**sig figs**

70.74074074 ^ 1/4 = a 2.900129566 = a Now I have to round to 3 significant digits. Is it 2.90 or 2.9001?

**Algebra**

Whitney invested $19,000, part at 5% and part at 7%. If the total interest at the end of the year is $1,110.,how much did she invest at 5%. I know the answer is $11,000. I would like to know how to actually solve the equation.

**MATH MIDDLE SCHOOL**

I love chocolate and coffee. I begin by making one cup of hot chocolate. I drink half of my cup and then I fill the cup with coffee. I stir the new mixture and drink half of the cup and then fill the cup again with coffee. I continue this pattern until I have consumed two full...