Thursday

July 24, 2014

July 24, 2014

Total # Posts: 199

**Math**

Mr. Jefferson has 20 students in his class. He wants to send 4 of these students to pick up books for the class. How many combinations of 4 students can he choose? A)5 B)80 C)4845 D)116,280

**Physics**

A 0.15kg baseball pitched at 30 m/s is hit on a horizontal line drive straight back at the pitcher at 46.0 m/s. If the contact time between bat and ball is 5x10^-3 s, calculate the force (assumed to be constant) between the ball and bat. [Hint: impulse!] I did FΔt = Δ...

**Consumers Math**

I don't want the answer to this question, but if someone could please tell me how to work it out, that would be great and I could finish it on my own. Thank you very much:) Question- Your station charges $15.95 for an oil change. As a promotion you sell six coupons for oil...

**world history**

Its about 1569 map Of the World Compare a modern Mercator Projection of eastern North America with Mercator's map. How are the two maps different? How are they similar?

**College Chemistry**

calculate the initial concentration of SCN- ions and Fe3+ ions when a solution was prepared by mixing 3.00mL of 0.00280M KSCN, 6.00 mL of 0.250M Fe(NO3)3 and 16ml of 0.050M HNO3.

**physics**

A) A hot air balloon has just lifted off and is rising at the constant rate of 1.70 m/s. Suddenly, one of the passengers realizes she has left her camera on the ground. A friend picks it up and tosses it straight upward with an initial speed of 10.4 m/s. If the passenger is 3....

**physics**

a)Two cars are traveling along a straight line in the same direction, the lead car at 24.5m/s and the other car at 29.6m/s. At the moment the cars are 41.6m apart, the lead driver applies the brakes, causing her car to have an acceleration of -2.00m/s2. How long does it take f...

**physics**

A model rocket is launched straight upward with an initial speed of 47.7 m/s. It accelerates with a constant upward acceleration of 2.02 m/s2 until its engines stop at an altitude of 157 m. What is the maximum height reached by the rocket? How long after lift off does the rock...

**Science**

idk

**Calculus**

Can some one please explain this problem to me? Find lim x->0 (sin5x/sin7x)

**science**

Compare and contrast the reproduction of mosses, ferns, gymnosperms, and angiosperms

**science**

why is sexual reproduction better than a sexual reproduction for ensuring the survival of a species in a changing environment?

**Statistics**

1 a 2a 3a 4a 5a 6a 7a 8a 9a 10a

**physics**

Using a small pendulum of length 0.171 m, a geophysicist observes that it completes 1 cycle every 0.833 s. What is the value of g at his location?

**Chemistry**

At 25C only .0190 mol of the generic salt AB2 is soluble in 1.00L of water. What is the Ksp of the salt at 25C? AB2<->A^2+ + 2B^- I took the .0190 mol and doubled it and multiplied by .019 again and got 6.859x10^-6 and got it wrong what should I do? Please help Dr. Bob

**Chemistry**

The hint says the acid and base will react completely until one or both is completely used up.

**Chemistry**

Complete this table of initial and final concentrations HF(aq) + KOH(aq) <-> KF(aq) + H20(l) Initial concentrations: HF-2.0M KOH-1.0M KF-0M Final Concentrations? how do I set this up to figure out the final concentrations? How can I tell which of the following best descr...

**Chemistry**

The correct pH is 3.17

**Physics**

a person jumps from a ledge 3.7 meters and when he drops to the ground it takes .7 meters for him to stop what is the force applied to his body . A person (46kg) UPDATED****

**Physics**

a person jumps from a ledge 3.7 meters and when he drops to the ground it takes .7 meters for him to stop what is the force applied to his body . A person (46kg) UPDATED****

**Physics**

a person jumps from a ledge 3.7 meters and when he drops to the ground it takes .7 meters for him to stop what is the force applied to his body

**Chemistry **

How would you prepare 50.0 mL of 2.0 M H2SO4 starting with concentrated sulfuric acid (18M)?

**Chemistry **

How would you prepare 50.0 mL of 2.0 M H2SO4 starting with concentrated sulfuric acid (18M)?

**pre calculus**

We are supposed to graph the equation then we are supposed to find the extreme values. I tried graphing it and I tried finding the extreme values. I came up with the max 5 and the min are -9 and -2. I am not sure if they are right because I watched a video online and didn'...

**pre calculus**

Hi, I am having a problem trying to find and understanding how to find the extreme values. I have a problem which I can't do. Will someone please explain for me how to do it. I would like to be able to do other similar problems. This is the problem I am stuck on: f(x)= x^...

**pre calculus**

Hi, I am having a problem trying to find and understanding how to find the extreme values. I have a problem which I can't do. Will someone please explain for me how to do it. I would like to be able to do other similar problems. This is the problem I am stuck on: f(x)= x^...

**physics**

An aircraft in straight and level flight is in a state of horizontal equilibrium. It is flying 120 km/hr in the direction 110* and not correcting for wind. The wind is blowing at 60 km/hr in the direction 340*. Determine the speed and direction the aircraft will actually fly.

**Ap bio**

Triiodobenzoic acid (TIBA) inhibits auxin transport. If a tiny agar bead containing TIBA were placed off center on the tip of an intact coleoptile, which way would the coleoptile bend: toward the side of the bead or away from it?

**physics**

two forces f1 and f2 are acting at a point such that the angles between them are (1) 30 degree (2) 60 degree and (3) 45 degree show that resultant forces will be

**physics**

two forces f1 and f2 are acting at a point such that the angles between them are (1) 30 degree (2) 60 degree and (3) 45 degree show that resultant forces will be

**Physics**

Why is R1 equal to 1?

**Physics**

When some stars use up their fuel, they undergo a catastrophic explosion called a supernova. This explosion blows much or all of a star's mass outward, in the form of a rapidly expanding spherical shell. As a simple model of the supernova process, assume that the star is a...

**Physics**

Calculate the kinetic energy that the earth has because of (a) its rotation about its own axis and (b) its motion around the sun. Assume that the earth is a uniform sphere and that its path around the sun is circular. For comparison, the total energy used in the United States ...

**Physics**

I figured it out. 2mg=mv3^2/r-mv1^2/r V3 being the speed at the top and V1 being the speed given at the bottom set them equal: V3^2=2gr+V1^2 sqrt(2*9.8*4.84+16.6^2) V3= 19.2459 m/s

**Physics**

It is located on the top

**Physics**

It is located on the top

**Physics**

How do I attach photos?

**Physics**

For the normal force in the drawing to have the same magnitude at all points on the vertical track, the stunt driver must adjust the speed to be different at different points. Suppose, for example, that the track has a radius of 4.84 m and that the driver goes past point 1 at ...

**Physics**

The final equation to use is: W=(GmM)/r^2 m=mass of satelite M=mass of planet What is the equation to find the mass of the planet?

**Physics**

A satellite has a mass of 6146 kg and is in a circular orbit 4.57 × 105 m above the surface of a planet. The period of the orbit is 1.6 hours. The radius of the planet is 4.44 × 106 m. What would be the true weight of the satellite if it were at rest on the planet&...

**Math**

On a Christmas package, Audrey needs to use only 40-cent stamps and 16-cent stamps. If she uses twice as many 40-cent stamps as 16-cent stamps, how many of each type of stamp must she use to mail a package costing $5.76 in postage?

**college physics**

A 55-kg woman cheats on her diet and eats a 465-Calorie (465 kcal) jelly doughnut for breakfast. (c) If the human body is only 24% efficient in converting chemical energy to mechanical energy, how many stairs must the woman climb to work off her breakfast? I got 24075.32468 st...

**college physics**

An aluminum cup contains 225 g of water and a 40-g copper stirrer, all at 27°C. A 400-g sample of silver at an initial temperature of 87°C is placed in the water. The stirrer is used to stir the mixture gently until it reaches its final equilibrium temperature of 32&de...

**math**

at the bowling alley Angela rented shoes for $3.00. It cost her $2.50 to bowl each game. develop an equation using the form C(x)=mx+b, where C(x) is the total cost and x is the number of games bowled.

**physics PLEASE HELP**

A hydraulic cylinder with a radius of 0.0268 m has a piston on the left end and a safety valve at the right end. The safety valve is a circular opening with a radius of 0.00639 m, sealed with a disk. The disk is held in place by a spring (spring constant = 964 N/m) that is com...

**physics**

The drawing shows an intravenous feeding. With the distance of 0.610 m, nutrient solution (ρ = 1010 kg/m3) can just barely enter the blood in the vein. What is the gauge pressure of the venous blood? Express your answer in millimeters of mercury.

**physics**

Between each pair of vertebrae in the spinal column is a cylindrical disc of cartilage. Typically, this disc has a radius of about 2.85 10-2 m and a thickness of about 7.14 10-3 m. The shear modulus of cartilage is 1.16 107 N/m2. Suppose that a shearing force of magnitude 10 N...

**neuroscience**

It's valid, for all you kids googling the answers to your homework :P

**History**

Plato and Aristotle both argued that political life should reflect humans' aspirations to live in a genuinely "good" society. However, their visions and ideas were very distinct. How were these "good societies" similar, and how were they different? Whos...

**Ap calculus**

Let h(x) = f (x-pi). Find the domain and range of h.

**accounting 205**

11,000

**ap chem**

you have 1.00 liter each of 0.10 M Na3PO4, Na2HPO4, NaH2po4 ka 1= 7.5*10^-3 ka2=6.2*10^-8 ka3=4.8*10^-13 a) prepare 500 ml of a buffer with PH= 7.6 b) how much 0.10 M HCL must be added to the 500ml of buffer to result in a PH=7.2 after the addition?

**Stats**

A public heath official wanted to know how often university students visit their student health centers due to illness or injury. The official took a nationwide random sample of 120 university students and found an average of (x bar) = 2.30 visits per student per year. It is k...

**chemistry**

Methanol (CH3OH) is used in the production of many chemicals. Methanol is made by reacting carbon monoxide and hydrogen at high temperature and pressure. CO(g) + 2 H2(g) CH3OH(g) (a) How many moles of each reactant are needed to produce 4.83 102 g CH3OH? CO mol H2 mol (b) Calc...

**chemistry**

Methanol (CH3OH) is used in the production of many chemicals. Methanol is made by reacting carbon monoxide and hydrogen at high temperature and pressure. CO(g) + 2 H2(g) CH3OH(g) (a) How many moles of each reactant are needed to produce 4.83 102 g CH3OH? CO mol H2 mol (b) Calc...

**math**

A cube of side length of 11cm and a mass of 2000g has what density?

**chemistry**

Thank you so much!

**chemistry**

I got 82g for the molar mass and I used the same method you demonstrated. We never learned the (H^+)=sqrt(k1k2) equation so I want to make sure I have the right answer. Did you get k2=9.3*10^-18

**chemistry**

a 205 mg sample of diprotic acid is dissolved in enough water to make 250 ml of solution. The pH of this solution is 2.15. A saturated solution of calcium hyrdoxide (Ksp=1.3*10^-6) is prepared by adding excess calcium hydroxide to water and then removing the undissovled solid ...

**chemistry**

explain how you would develop a scheme to separate and identify ag, pb, fe,and al in a solution that might contain all four as ions

**Physics**

The potetial energy of a spring is 0.25 J when it is compressed 0.05m to the left of the equilibrium position. At this point it comes to its leftmost position. What is its kinetic energy when it returns to its equilibrium point? a. zero b. 0.25 J and the object is moving to th...

**spelling **

What does v/cv and v/va mean

**geometry**

Find the area of a circle circumscribed about an equilateral triangle whose side is 18 inches long.

**spell**

I need 6 letter word with second letter is I and fourth letter is Y. No more vowels.

**algebra**

The Physical Education Deparment sells t-shirts for $12 and shorts for $8. One month, they sold 77 total items for $780 in total. How many t-shirts did they sell?

**Physics**

7.53

**Chemistry**

What is the mass of 14 liters of gasoline? Assume that the density of gasloine is .680 grams per cubic centimeter. Provide answer in kilograms.

**Calculus**

If the slope is 3, find an equation of the tangent line to the curve at P(8, -3).

**Physics**

8m/s

**math**

im sorry my computer had the jitters you dont have to be rude so excuse me!

**math**

the answer is u divided by mg equals h?

**math**

the answer is u divided by mg equals h?

**HELP PLZ**

please help

**math**

u = m*g*h find the value of h show work please

**9/11**

in new york they have many memorials

**Road Building+Environment**

Deforestation was a concern. The new technologies disrupted the natural balance of the ecosystem and contributed to climate change, which is a major issue today.

**Road Building+Environment**

Deforestation was a concern. The new technologies disrupted the natural balance of the ecosystem and contributed to climate change, which is a major issue today.

**algebra**

The formula R =−0.0026? + 4.0807 can be used to predict the world record, in minutes, for the 1500-m run t years after 1900. Determine (in terms of an inequality) those years for which the world record will be less than 3.8 min.

**history**

The first one I would put mercantilism. Second is true. Third is assembly line. Fourth is true. Fifth is labor union. Sixth is imperialism. Seventh I think is a truce. Eighth is depression. Ninth sit-down strike. Tenth is blitzkrieg. Eleventh is true. Twelth is MIC or military...

**math final studying**

a triangular road sign has a height of 8 feet and a base of 16.5 feet.how much larger in area is this sign than one with a height of 4 feet and a base of 8.25 feet?

**math final studying**

so my answer issss a 90?

**math final studying**

oh so i will multiply 75 and 1.20

**HELPPPPPP**

plz answer me

**math final studying**

i have no idea what that means?

**math final studying**

beth scored 75 on her first math test. she scored 20 % higher on her next math test. what did she score on the second test?

**math final studying**

okay thank u both umm so the answer was 78 i also had gotten that answer

**math final studying**

an architect is building a model of a tennis court for a new client. on the model the court is 6 inches wide and 13 inches long. an official tennis court is 36 feet wide. what is the length of the court?

**math final studying**

thank u

**math final studying**

the distance between bases on a baseball feild is 90 feet.if 3 players hit home runs during a game and each runs around all 4 bases what is the total distance the player run?

**WRITING**

HELP ME

**WRITING**

how to give credit to line from a book that your putting in your research paper?

**WRITING**

how does this sound:Finding a career may be difficult, but comparing facts and researching may help. Being a news anchor

**WRITING**

well my teacher dosent want persuwasive i need a non opion factual paper and i have no idea how to get it going

**WRITING**

i need like an example of how to start it bcuz when i start it it sounds persuwasive

**WRITING**

well im just now beging my draft but the just of it is a news anchor woukd be a good carrer for me because the skills needed for this career and that i love the idea of it and so forth but i dont no what to do for the introduction

**WRITING**

im doing a reserch paper on being a news anchor i need an opening sentence a hook i no it goes for personal prefrence but could someone help me get an idea pls

**math**

actally 2 dif ppl we in same class and i showed her the website and she typed q after i did. thank u

**math**

how do u get that

**chemistry**

thanks

**chemistry**

how many ML of each of the following solutions will provide 25.0g of KOH? A)2.50 M of KOH b)0.750 M of KOH c)5.60 M of KOH NEED HELP setting up problem!!