Wednesday

September 28, 2016
Total # Posts: 3,489

**Algebra**

You need to set up a system of equations. No one knows how many of each type of bill there is. Let t=twenties and f=fifties. t+f=36 20t+50f=1170 -20(t+f=36)=-20t+-20f=-720 20t+50f=1170 30f=450 f=15 t+15=36 -15 -15 t=21

*December 5, 2012*

**algebra-NOW PLEASE**

A boat is traveling in a river with a current that has a speed of 1.5 km/h. In one hour, the boat can travel twice the distance downstream as it can travel upstream. What is the boat's speed in still water?

*December 4, 2012*

**Algebra**

Simple. 70=7w

*December 4, 2012*

**Algebra**

[4(5)+-4]raised to 2nd (20+-4)raised to 2nd 16 raised to 2nd 256 is the answer

*December 4, 2012*

**Trig**

A population of animals oscillates annually from a low of 1300 on January 1st to a high of 2200 on July 1st, and back to a low of 1300 on the following January. Assume that the population is well-approximated by a sine or a cosine function. a. Find a formula for the population...

*December 3, 2012*

**Chemistry Help**

T=PV/nR P=0.96 V=0.045 n=0.002 g/mol R=0.082057

*December 2, 2012*

**Chemistry Help**

Using the accurate concentration that you measured in Part A (which is 14.77 ml), calculate the mass of HCl (in grams) present in a 15.00-mL sample of the acid solution, using proper dimensional analysis

*December 2, 2012*

**College Chemistry**

Using the accurate concentration that you measured in Part A (which is 14.77 ml), calculate the mass of HCl (in grams) present in a 15.00-mL sample of the acid solution, using proper dimensional analysis

*December 2, 2012*

**Math (Calculus)**

Use implicit differentiation to find the slope of the tangent line to the curve y/(x–9y)=x^6–2 at the point (1,-1/-8). Can someone please help me? I dont understand

*November 30, 2012*

**MAth t**

i d k but if youre in math course 7th grade im in too and u dont answer if u dont kno it cuzz this is one of the challenege questions teacher just mark as extra credit if u want but it really doesnt count

*November 30, 2012*

**Math (Calculus)**

A spherical snowball is melting in such a way that its diameter is decreasing at rate of 0.3 cm/min. At what rate is the volume of the snowball decreasing when the diameter is 10 cm. Can someone help & explain how to solve this question? Please.

*November 29, 2012*

**math**

Estimate a 15% tip on a taxi ride that costs $23.25.

*November 29, 2012*

**math**

72 is what percent of 480? Write and solve an equation to solve the problem

*November 29, 2012*

**math **

Jessica bought a computer for $325 and had to pay 6% sales tax. What was the total cost of Jessica’s computer?

*November 29, 2012*

**Steveeee help plz**

What is the area is square units o the region under the curve of the function f(x)=4, on the interveral from x=-1 to x=3

*November 28, 2012*

**Steve help pleaseeeee **

Two promotional stands are to be placed in an ellipse shaped room. One at each foci and are 3 units from center. If the room is 8 units wide what is the length

*November 28, 2012*

**math**

y1= sin (x) y2= (tanx) It is graphed in the interval [0, pi/2] find the integral

*November 28, 2012*

**calculus**

y1= sin (x) y2= (tanx) It is graphed in the interval [0, pi/2] find the integral

*November 28, 2012*

**5th grade Language Arts**

Thanks Ms. Sue! I have other sentences I would like to try to get right. 1. Mr. Morton, the best reading teacher in the world, taught me sentence structure. Complex: Mr. Morton taught me sentence structure = indep & best reading teacher in the world = dep 2. I left early so ...

*November 26, 2012*

**5th grade Language Arts**

I need help classifying sentences (compound, complex, compound-complex). Here's the sentence: I got in trouble so I can't go to the party, but it would have been fun. I answered it was complex which I got wrong.

*November 26, 2012*

**Physics **

Electromagnetic waves can form standing waves. In a standing wave pattern formed from microwaves, the distance between a node and an adjacent antinode is 0.63 cm. What is the microwave frequency? any help is much appreciated

*November 23, 2012*

**physics**

Linearly polarized light is incident on a piece of polarizing material. What is the ratio of the transmitted light intensity to the incident light intensity when the angle between the transmission axis and the incident electric field is (a) 30° and (b) 71°? Help! :(

*November 23, 2012*

**physics**

An object is located 16.8 cm in front of a convex mirror, the image being 11.5 cm behind the mirror. A second object, twice as tall as the first one, is placed in front of the mirror, but at a different location. The image of this second object has the same height as the other...

*November 23, 2012*

**Physics**

The two blocks in the figure below, m1 = 1.2 kg and m2 = 4.8, are connected by a massless rope that passes over a pulley. The pulley is 12 cm in diameter and has a mass of 2.0 kg. As the pulley turns, friction at the axle exerts a torque of magnitude 0.38 N·m. If the ...

*November 21, 2012*

**Civics**

1.The constitution grants the federal courts ____ in several different kinds of court cases. This gives them the authority to hear and decide cases properly brought before them. 2. The lowest federal courts are trial courts, which have ___, the authority to hear and decide a ...

*November 20, 2012*

**physics**

An open train car, with a mass of 2070 kg, coasts along a horizontal track at the speed 2.31 m/s. The car passes under a loading chute and, as it does so, gravel falls vertically into it for 3.25 s at the rate of 491 kg/s. What is the car's speed after the loading is ...

*November 19, 2012*

**Physics**

dude I have no idea what you just typed.. can you please clarify what all the variables you used stand for?

*November 19, 2012*

**Physics **

A thrill-seeking cat with mass 4.00 kg is attached by a harness to an ideal spring of negligible mass and oscillates vertically in SHM. The amplitude is 0.050 m, and at the highest point of the motion the spring has its natural unstretched length. Calculate the elastic ...

*November 19, 2012*

**Physics**

A plane drops a bomb from an altitude of 10,000m. a. Determine the time the bomb is in the air. b. Determine the velocity the bomb would have right before it hits the ground. c. Before the bomb is launched the plane has a horizontal velocity of 92m/s. Determine the distance ...

*November 19, 2012*

**Chemistry Help**

Write the net ionic equation for the reaction of calcium nitrate and sodium phosphate

*November 14, 2012*

**Chemistry Help**

If you mixed 10.0 mL of calcium nitrate and sodium phosphate, both 0.250M,which of the two would be the limiting reactant?

*November 14, 2012*

**Stoichiometry**

n=M/RFM n=number of moles RFM= relative formula mass n=17/18=0.944 0.944 moles then 0.944=x/16 x=0.944*16 x=15.104 15.105 grams

*November 14, 2012*

**Physics**

G: Vi = 50m/s Degree = 37 U: Vy, Vx, Dy, Dx, T E: Vy = Vi(Sin(θ)), Vx = Vi(Cos(θ), Dy = Vy(1/2)(t) + 1/2(a)(1/2t^2) Dx = Vx(t) (Because the speed is constant) t = 6.14 s, h = 46.2, Δx = 245.2 m

*November 13, 2012*

**chemistry (molecular calculations)**

If you had 78.2 grams of K, how much oxygen is needed to convert it all to K2O?

*November 13, 2012*

**math**

A material has a half-life of 12 hours. If initially there are 4 grams of the material, how much is present after 8 hours? I know the answer is 8/3, but how would you solve this using calculus? please help.

*November 11, 2012*

**Math**

Is this correct? If one card is drawn from a regular deck of cards,what is the probability the card will not be an ace? 1/13 is the probability

*November 9, 2012*

** Math**

If one card is drawn from a deck of cards,what is the probability the card will not be an ace? I think the answer is 1/13. Am I correct???

*November 9, 2012*

**Geography**

Is this correct? 1. The closest ocean to Mongolia is the Pacific Ocean. 2. The capital of the island nation that has the Sea of japan as its western border is Tokyo, Japan. Thank You

*November 9, 2012*

**physics**

A car travels in a straight line for 4.8 h at a constant speed of 57 km/h . What is its acceleration? Answer in units of m/s

*November 8, 2012*

**Physics Help**

Two compressible solids are formed into spheres of the same size. The bulk modulus of sphere two is twice as large as the bulk modulus of sphere one. You now increase the pressure on both spheres by the same amount. As a result of the increased pressure, how is the change in ...

*November 7, 2012*

**Implicit differentiation **

implicit differentiation of x^3y^2-5x^2y+x=1

*November 7, 2012*

**Chemistry**

7.0

*November 3, 2012*

**calculus**

This is the problem that I got. I thought of that too. I think that it might just be a type? x is probably suppose to be h...

*November 3, 2012*

**calculus**

Given: y^2+h^2=1 Find h as a function of y. If expression for dy/dx includes h, substitute the expression in terms of y for h. Write dy/dx in terms of y only. Show that x=[(1+sqrt(1-y^2))/y]-sqrt(1-y^2) satisfies the differential equation you found to prove this equation ...

*November 3, 2012*

**calculus**

Given: y^2+h^2=1 Find h as a function of y. If expression for dy/dx includes h, substitute the expression in terms of y for h. Write dy/dx in terms of y only. Show that x=[(1+sqrt(1-y^2))/y]-sqrt(1-y^2) satisfies the differential equation you found to prove this equation ...

*November 3, 2012*

**Chem**

The following substances undergo complete combustion in a bomb calorimeter. The calorimeter assembly has a heat capacity of 5.136 ^ C. In each case, what is the final temperature if the initial water temperature is 22.37^ C? 0.3268g caffeine, C8H10N4 (heat of combustion = -...

*October 29, 2012*

**College Chemistry**

Calculate the heat in joules needed to warm 225g of water from 88.0 degrees Celsius to its boiling point 100.0 degrees Celsius

*October 24, 2012*

**Biology**

1)Animal cells prefer to be in isotonic solution, while plant cells prefer to be in hypotonic solution. Explain what this means and why it is so. 2.) In terms of Gibbs free energy, what does “unstable” mean? Also, give at least two additional ways to say that a ...

*October 24, 2012*

**physics**

A box slides down a plane 8 m long that is inclined at an angle of 30 degrees with the horizontal. If the box starts from rest and u = 0.25, find a.) the acceleration of the box, b.) it's velocity at the bottom of the plane, and c.) the time required for it to reach the ...

*October 23, 2012*

**Math**

Sare estimated 32x45 by using 30x40. How could Sara make a more accurate estimate?

*October 22, 2012*

**Calculus 1**

Find the derivative of y with respect to x. y=(x^6/6)(lnx)-(x^6/36) So far this is what I've gotten: y=(x^6/6)(lnx)-(x^6/36) y=(1/6)x^6(lnx)-(1/36)x^6 y'=(1/6)x^5(1/x)+lnx(x^5)-(1/6)x^5 What do I do now?

*October 22, 2012*

**CHEMISTRY**

Explain Why The Addition Of An Electron To A Chlorine Atom Is An Exothermic Process And The Addition Of An Electron To A Magnesium Atom Is An Endothermic Processs

*October 22, 2012*

**math**

what is the prime factorization of 1 bilion using exponents?

*October 22, 2012*

**Physics**

Can you tell me the answer for c and d. I got the one for a and b correct but c says it's not correct. I put 21.96N.

*October 21, 2012*

**Physics**

A 2.42kg block starts from rest at the top of a 22.9◦ incline and accelerates uniformly down the incline,moving 2.41m in 2.14s. The acceleration of gravity is 9.81m/s2. a) What is the magnitude of the acceleration of the block? Answer in units of m/s2 b) What is the coe...

*October 21, 2012*

**Chemistry**

Then if it Decrease the system will shift to the side with more moles of gas?

*October 21, 2012*

**Chemistry**

I have a question about this one 2N2O(g) ⇋ O2(g) + 2N2(g), what happens to the equilibrium position if the pressure decreases? Is going to shift to the right or to the left???

*October 21, 2012*

**Geography**

5 countries in Africa with coastlines on the Atlantic Ocean and lie between 20 degrees n and 10 degrees n? I think they are guinea,guinea-Bissau,Gambia,Senegal and Mauritania. Is this right?

*October 20, 2012*

**statistics**

Given the length an athlete throws a hammer is a normal random variable with mean 50 feet and standard deviation 5 feet, what is the probability he throws it between 50 feet and 60 feet?

*October 19, 2012*

**Physics (Difficult)**

A uniform rectangular bar with cross-section 66 mm x 54 mm and of length 1.7 m has mass 16kg. It pivots about an axis prependicular to the wider face. The axis is equidistant from the edges and 170 mm from one end. What is the relevant second moment of mass?

*October 19, 2012*

**physics**

A 0.395-kg blue bead slides on a frictionless, curved wire, starting from rest at point in the figure below, where h = 1.50 m. At point , the blue bead collides elastically with a 0.650-kg green bead at rest. Find the maximum height the green bead rises as it moves up the wire.

*October 18, 2012*

**physics**

a .77 kg book with dimensions of 28.9 cm by 20.2 cm is on a table. What force does the book apply on the table?

*October 17, 2012*

**geography**

Is mexico the large north american country that the tropic of cancer cuts through?

*October 17, 2012*

**math 7**

the weight of thewater in a full bathtub in a quarter ton. How many pounds is a quarter ton/

*October 17, 2012*

**Physics**

A crank of length 190mm is initially at 65 degree above the horizontal, and rotates through 35 degree towards the horizontal. A vertically downward force of 160 N acts on the outer end of the crank. Calculate the work done by the force.

*October 17, 2012*

**Physics**

A car travels in a flat circle of radius R. At a certain instant the velocity of the car is 24 m/s west,and the acceleration of the car has componets of 2.4 m/s^2 east and 1.8m/s^2 south. Find the total displacement of the object (from t=0 to 25)

*October 16, 2012*

**College Chemistry**

We will calculate the amount of acid to use in each titration. Assume that you are using 0.0512 M NaOH(aq). A good volume of NaOH(aq) to use per titration is 15mL. From this molarity and volume, the moles of NaOH can be calculated. Since the unknown acid is monoprotic, this ...

*October 15, 2012*

**Algebra**

He isn't supposed to give you the answers. You should be greatful he helped you find them.

*October 15, 2012*

**physics**

help! Two charges A and B are fixed in place, at different distances from a certain spot. At this spot the potentials due to the two charges are equal. Charge A is 0.22 m from the spot, while charge B is 0.54 m from it. Find the ratio qB/qA of the charges.

*October 11, 2012*

**physics **

trying to study but stuck with this one. Two tiny spheres have the same mass and carry charges of the same magnitude. The mass of each sphere is 4.62 x 10-6 kg. The gravitational force that each sphere exerts on the other is balanced by the electric force. Determine the charge...

*October 11, 2012*

**Physics**

Two cars pass each other traveling at the same speed. One car has a constant velocity of 18.0 m/s east. The other car has a constant acceleration of 3.00 m/s^2, west. How much time will have elapsed until the cars are 128 m apart?

*October 11, 2012*

**geography**

Is this correct? The Caribbean Sea is the second largest sea in the world that is south of cuba.

*October 10, 2012*

**Math **

Find the limit of (2cosx+3cosx-2)/(2cosx-1)as x tends to pi/3.

*October 10, 2012*

**phy**

Integral of F(x) = .5mv^2 18x-.5(.53)x^2=.5mv^2 find v.

*October 9, 2012*

**Chemistry**

If the Kb of a weak base is 2.6 × 10-6, what is the pH of a 0.24 M solution of this base?

*October 6, 2012*

**Chemistry**

extremely easy. Sorry! pH=1 and pOH = 13

*October 6, 2012*

**Chemistry**

Calculate the pH and the pOH of an aqueous solution that is 0.025 M in HCl(aq) and 0.075 M in HBr(aq) at 25°C.

*October 6, 2012*

**calculus**

Prove (by using a point and a normal vector) that the plane whose intercepts with the coordinate axes are x=1, y=1, and z=1 is given by the equation x+y+z=1

*October 4, 2012*

**Algebra**

i dont know how to do it

*October 3, 2012*

**physics**

Please help! Two charges are placed on the x axis. One of the charges (q1 = +8.71C) is at x1 = +3.00 cm and the other (q2 = -28.6C) is at x2 = +9.00 cm. Find the net electric field (magnitude and direction given as a plus or minus sign) at (a) x = 0 cm and (b) x = +6.00 cm.

*October 2, 2012*

**chemisry**

compare and contrast the abilities of carbon, sodium, and neon to form chemical bonds?????

*October 1, 2012*

**physics**

need help with this problem A charge of -2.73 uC is fixed in place. From a horizontal distance of 0.0465 m, a particle of mass 9.50 x 10-3 kg and charge -9.56 uC is fired with an initial speed of 97.2 m/s directly toward the fixed charge. What is the distance of closest ...

*September 30, 2012*

**properties and mental math**

use properties and mental math to find the value of (86 + 27) + 3

*September 30, 2012*

**Physics**

Two charges are placed on the x axis. One of the charges (q1 = +8.71C) is at x1 = +3.00 cm and the other (q2 = -28.6C) is at x2 = +9.00 cm. Find the net electric field (magnitude and direction given as a plus or minus sign) at (a) x = 0 cm and (b) x = +6.00 cm. Please help!

*September 28, 2012*

**college physics**

Two charges are placed on the x axis. One of the charges (q1 = +8.71C) is at x1 = +3.00 cm and the other (q2 = -28.6C) is at x2 = +9.00 cm. Find the net electric field (magnitude and direction given as a plus or minus sign) at (a) x = 0 cm and (b) x = +6.00 cm. Please help!

*September 28, 2012*

**Chemistry**

a solution is 0.0300 m in Sodium. How many grams of sodium carbonate are necessary to prepare 900.0 ml of this solution? I don't know where to start on this.

*September 28, 2012*

**chemistry**

order Se, S, As, by increasing atomic radius? explain why?

*September 26, 2012*

**chemistry**

a buffer is a substance which? a) accepts OH- in basic solution b) accepts H+ in acid solutions

*September 26, 2012*

**chemistry**

whats an example of hydrogen bonding?

*September 26, 2012*

**math**

I don,t know that what I am trying to firgure that oug. I even looked in a math book. Nothing. T

*September 24, 2012*

**math**

what is 8x3x3 in exponential form

*September 23, 2012*

**chemistry**

How many moles of aluminum do 5.9×1024 aluminum atoms represent?

*September 22, 2012*

**physics**

A truck driver attempting to deliver some furniture travels 5 km east, turns around and travels 5 km west, and then travels 12 km east to his destination. What distance has the driver traveled?

*September 22, 2012*

**Maths**

I LOVE MATHS 5+5=10

*September 18, 2012*

**Physics**

An athlete springs a circular 400.0 m track in 50.0 s. Asume he runs a constant speed. a. What is his speed over the entire course? b. What is the magnitude of his instantaneous velocity at any point along the circuit? c. If he starts facing west and runs counterclockwise, ...

*September 17, 2012*

**math**

A factory can produce two products, x and y, with a profit approximated by P = I think it's b but I'm not really sure. Can someone show me how to do this or let me check my answer? :) 14x + 22y – 900. The production of y can exceed x by no more than 200 units. ...

*September 17, 2012*

**Algebra**

(9a^3b^4-12a^2b^5+6ab^7)/(6a^2b^3)

*September 17, 2012*

**environment**

The ideal study plan includes which of the following? A. Quality preparation. B. Use of as much different intelligence as possible. C. Both A & C. D. An elaborate study environment.

*September 16, 2012*

**readind**

Which is the best way to learn new material? A. Consistently study the same way. B. Review notes every day. C. Use techniques that appeal only to your preferred learning style. D. Use techniques that appeal to all three learning styles.

*September 16, 2012*