Friday

September 19, 2014

September 19, 2014

Total # Posts: 196

**Math**

Brian gave 20% of his baseball cards to Scott and 15% to Adam. If he still had 520 cards, how many did he have originally?
*July 30, 2014*

**Math terminal zeroes**

Scratch that. Never mind.
*July 25, 2014*

**Math terminal zeroes**

If a number ends in zeroes, the zeroes are called terminal zeroes. For example, 520,000 has four terminal zeroes, but 502,000 has just 3. Let X equal the product of all natural numbers from 1 to 20. N = 1 * 2 * 3... *20. How many terminal zeroes will N have when it is written ...
*July 25, 2014*

**Physics **

A 69.5kg football player is gliding across very smooth ice at 2.15m/s . He throws a 0.470kg football straight forward. A) What is the player's speed afterward if the ball is thrown at 16.0m/s relative to the ground? B) What is the player's speed afterward if the ball ...
*May 27, 2014*

**math**

what would the graph of y=x^2+1 look like A. a straight line B. a parabola C. a dotted line D. none of the above
*May 26, 2014*

**science**

Which of the following is the most effective way to preserve biodiversity? (1 point) captive breeding habitat destruction habitat preservation habitat fragmentation
*May 15, 2014*

**math**

CD sales at corner music increased 145% last year. which number is equivalent to 145%? A. 14,500 B. 145 C. 1.45 D. O.O145 i think C but im not sure
*May 14, 2014*

**english**

if you read the giver can you please check my answers and see if they are correct? . What is the jonas apprehensive about at the beginning of the novel? A. a plane flying over the community B. a dream that he had recently C. the upcoming ceremony and his assingment I think C 2...
*May 13, 2014*

**english**

Jane Goodall, a primatologist, studies the social and family lives of chimpanzees.
*May 13, 2014*

**LA**

1. What is the jonas apprehensive about at the beginning of the novel? A. a plane flying over the community B. a dream that he had recently C. the upcoming ceremony and his assingment I think C 2. In Jonas's community, members are released from the community under which ...
*May 13, 2014*

**LA**

Can you check my answers?
*May 13, 2014*

**LA**

has anyone read the giver?
*May 13, 2014*

**history**

1 C and 2 D?
*May 12, 2014*

**history**

1. Which factor contributed most to the beginning of the women's rights movement in the United States during the mid-1800s? A. A dramatic increase in women's participation in the workforce *** B. A shift in social attitudes brought on by increased sectional tensions C...
*May 12, 2014*

**science**

the current atomic model would be revised if A. better microscopes were being used to study its structure. B.better microscopes are invented in the future. C. new information about an atom's structure is discovered. D. a new element is discovered in the future
*May 8, 2014*

**math**

simplify 10p4 A. 210 B. 360 C. 5,040 D. 151,200 simplify 9c4 A. 126 B. 15,120 C. 5 D. 3,024
*May 7, 2014*

**math**

a basket contains the following pieces of fruit: 3 apples, 2 oranges, 2 bananas, 2 pears, and 5 peaches. Jameson picks a fruit at random and does not replace it. Then Brittany pricks a fruit at random. What is the probability that Jameson gets a banana and Brittany gets a pear...
*May 7, 2014*

**math**

each of two urns contains green balls and red balls. urn I contains 8 green balls and 12 red balls. Urn II contains 5 green balls and 8 red balls. if a ball is drawn from each urn, what is P(red and red)? A. 79/65 B. 24/65 C. 20/33 D. 2/13
*May 7, 2014*

**math**

i meant red
*May 7, 2014*

**math**

a bag contains 7 green marbles, 9 red marbles, 10 orange marbles, 5 brown marbles, and 10 blue marbles. you choose a marble, replace it, and choose again. what is P(read, then blue)? A. 77/164 B. 19/41 C. 90/1681 D. 45/41
*May 7, 2014*

**math**

Food Express is running a special promotion in which customers can win a free gallon of milk with their food purchase if there is a star on their receipt. So far, 129 of the first 138 customers have not received a star on their receipts. What is the experimental probability of...
*May 7, 2014*

**math**

thank you!!
*May 7, 2014*

**math**

a number cube is rolled 150 times. the number 3 comes up 43 times. hat is the experimental probability of rolling a 3? what is the theoretical probability of rolling a 3? A. 43/150 ; 1/6 B. 43/150 ; 1/50 C. 1/6 ; 43/150 D. 3/43 ; 1/6
*May 7, 2014*

**chemistry**

The generic metal A forms an insoluble salt ABsolid and a complex AC5aqueous. The equilibrium concentrations in a solution of AC5 were found to be A is 0.100 M, C is 0.0320 M, and AC5 is 0.100 M. Determine the formation constant Kf of AC5
*May 7, 2014*

**chemistry**

The solubility of AB(s) in a 1.000-M solution of C(aq) is found to be 0.121 M. What is the Ksp of AB?
*May 7, 2014*

**Algebra 1 math**

Deborah rolls two fair dice. What is the probability that the sum of the numbers rolled is 7?
*April 29, 2014*

**urgent (physics)**

A certain planet is located 3.54 x 10^11 m from its sun. If its orbital period is 4.9 x 10^7 s, find the mass of its sun.
*April 24, 2014*

**math**

Thank you so much
*April 14, 2014*

**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 (...
*April 14, 2014*

**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 ...
*April 3, 2014*

**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?
*March 14, 2014*

**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
*March 14, 2014*

**geometry**

THANK STEVE i HAVE THE ASNWER
*March 1, 2014*

**geometry**

IT DOESNT SAY STEVE
*March 1, 2014*

**geometry**

If A point K is the reflection of L (2,5) IN THE Y AXIS WHAT IS THE LENGTH OF KL
*March 1, 2014*

**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.
*February 23, 2014*

**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?
*November 20, 2013*

**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?
*November 20, 2013*

**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?
*October 28, 2013*

**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.
*October 26, 2013*

**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...
*October 1, 2013*

**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 ...
*September 27, 2013*

**algebra**

((5w^2-16w+3)/(5w^2+24w-5))/((15w^2-8w+1)/(3w^2+14w-5))
*September 27, 2013*

**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?
*September 22, 2013*

**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 ...
*September 22, 2013*

**maths**

thank you
*September 15, 2013*

**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 ...
*September 15, 2013*

**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 ...
*June 23, 2013*

**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
*May 21, 2013*

**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.)
*May 21, 2013*

**Physics**

i input your formula and false
*May 21, 2013*

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

0.881
*May 20, 2013*

**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 ...
*May 20, 2013*

**Math**

Thank you Steve.
*May 8, 2013*

**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.
*May 8, 2013*

**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 ...
*May 3, 2013*

**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 ...
*April 12, 2013*

**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 ...
*April 9, 2013*

**math **

x+2/3x-6*x^2-3+2/x^2-x-6
*March 4, 2013*

**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 ...
*February 21, 2013*

**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.
*November 1, 2012*

**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
*October 28, 2012*

**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 ...
*October 27, 2012*

**Physics**

Thank you very much Elena for that and also for promptly answering my question on a timely manner!!!
*October 25, 2012*

**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 ...
*October 25, 2012*

**physics**

Thank you!
*October 24, 2012*

**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 ...
*October 24, 2012*

**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 ...
*October 24, 2012*

**algebra**

=12+24*6*2-17 =283
*October 24, 2012*

**Physics**

thank you!
*October 23, 2012*

**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
*October 23, 2012*

**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 ...
*October 14, 2012*

**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 ...
*July 14, 2012*

**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 ...
*July 14, 2012*

**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 ...
*July 9, 2012*

**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 ...
*June 24, 2012*

**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 (...
*May 8, 2012*

**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
*May 7, 2012*

**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
*May 6, 2012*

**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...
*May 6, 2012*

**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...
*May 6, 2012*

**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 ...
*April 3, 2012*

**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 ...
*April 2, 2012*

**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)
*March 29, 2012*

**chemistry**

sorry. time is in minutes not seconds
*March 25, 2012*

**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 ...
*March 25, 2012*

**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?
*March 24, 2012*

**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?
*March 24, 2012*

**AP CHEMISTRY**

Someone please answer my question below in AP CHEMISTRY.
*March 19, 2012*

**AP CHEMISTRY**

thanx!!
*March 19, 2012*

**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 ...
*March 19, 2012*

**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
*March 13, 2012*

**AP CHEMISTRY**

THANX!!!
*March 13, 2012*

**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.
*March 13, 2012*

**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
*March 12, 2012*

**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 ...
*March 12, 2012*

**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 ...
*March 9, 2012*

**AP CHEMISTRY**

i asked another question in my post below pleaseeeeeeeee answer it.. THANX!!!!!!!
*March 8, 2012*

**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)
*March 8, 2012*

**AP CHEMISTRY**

thank u and next time i will show some work
*March 8, 2012*