Friday

November 21, 2014

November 21, 2014

Total # Posts: 74,429

**chemistry**

Nitride has a charge of -3, while sodium has a +1 charge. Thus, a molecule of sodium nitride would need three sodium ions to counteract the -3 charge. The molecule would be Na3N
*October 26, 2014*

**Calculus**

C = 2πr C' = 2π [This equals the rate at which the circumference is changing] A = πr^2 A' = 2πr [This equals the rate at which the area is changing] A' = 2C' 2πr = 2(2π) 2πr = 4π r = 4π/2π r = 2 So, the answer ...
*October 26, 2014*

**Calculus**

The radius of a circle is increasing. At a certain instant, the rate of increase in the area of the circle is numerically equal to twice the rate of increase in its circumference. What is the radius of the circle at that instant? A. 1/2 B. 1 C. Sqrt 2 D. 2 E. 4
*October 26, 2014*

**math**

F = 3K F = E + 15 K = E - 1 You can plug in either 3K or (E+15) for F, so now you've got this equation: 3K = E + 15 We know that Kevin = E - 1, so we plug that in for K: 3(E-1) = E + 15 3E - 3 = E + 15 2E = 18 E = 9 [So, Eileen must be 9] Plug in 9 for E to find Kevin'...
*October 26, 2014*

**PHYSICS (VECTOR)**

46 km/h [Horizontal] ---> \. | .\.| ..\v -474.8 km/h [Vertical] We're trying to find the angle in the top left corner of the triangle above. We already have the lengths of the two legs, so we'd do this using tan. Tan(x) = Opposite/Adjacent Tan(x) = (-474.8)/(46) = -...
*October 26, 2014*

**math**

P varies directly as the square root of q. P=8 when q =25 find p when q = 100
*October 26, 2014*

**physics**

Depends on what the acceleration and initial velocity are. Here's an equation that might help with that: Vf = Vo + at (Where vf = final velocity, vo = initial velocity, a = acceleration, and t = time) Assuming the car is starting from rest, this would be your equation: Vf...
*October 26, 2014*

**physics**

how much will the velocty of a car be in 24 seconds
*October 26, 2014*

**Math**

There's only one way to arrange 19 cubes such that a rectangle is formed, and that's by lining them all up in one 19-cube row. So, 1.
*October 26, 2014*

**physics**

x = t^4 - 6t^2 + 9t Take the derivative to get the velocity. v = 4t^2 - 12t + 9 Take the derivative again to get acceleration. a = 8t - 12 Now, let's shift to force formulas. F = ma If a = 0, F = 0. Therefore, the net force on the locomotive is equal to zero at the time ...
*October 26, 2014*

**physics**

The position of a toy locomotive moving on a straight track along the x-axis is given by the equation x = t4 − 6 t2 + 9 t , where x is in meters and t is in seconds. The net force on the locomotive is equal to zero when t is equal to
*October 26, 2014*

**physics**

A copper (Young's modulus 1.1 x 1011 N/m2) cylinder and a brass (Young's modulus 9.0 x 1010 N/m2) cylinder are stacked end to end, as in the drawing. Each cylinder has a radius of 0.14 cm. A compressive force of F = 4800 N is applied to the right end of the brass ...
*October 26, 2014*

**Chemistry**

Element X consists of two major isotopes with the following percent abundances and atomic masses: 35.0% and 85.0 amu; and 65.0% and 84.0 amu. Calculate the average atomic mass of element X.
*October 26, 2014*

**chemistry**

which unit is used to express the pressure of gas?
*October 26, 2014*

**French**

Yes, but is either of them correct?
*October 26, 2014*

**French**

Is it grammatically correct to say "Un prof enseigne les/des élèves"?
*October 26, 2014*

**Physics**

A solid wood door, 90.0 cm wide by 2.00 m tall has a mass of 35.0 kg. It is open and at rest. A small 500-g ball is thrown perpendicular to the door with a speed of 20.0 m/s and hits the door 60.0 cm from the hinged side. The ball rebounds with a speed of 16.0 m/s along the ...
*October 26, 2014*

**physics**

1- An elevator, when fully loaded, has a mass of 5500 kg. The elevator needs to accelerate anywhere from 2.7 m/s^2 [D] to 2.7 m/s^2 [U]. What is the maximum tension force that the elevator cable will need to support during normal use? can we use fnet principle here, so when ...
*October 26, 2014*

**physics**

A 83 kg person is hanging off the edge of a cliff, holding a rope. A 101 kg person is on the top of the cliff holding the other end of the rope. Find the minimum coefficient of static friction that would prevent the 83 kg person from falling.
*October 26, 2014*

**chemistry**

2.) If you pass 10.0mL of a 50.0mL solution of [Co(en)2Cl2]Cl that has been reduced with Zn through a cation exchange column, you will obtain a solution that has three H+ ions for every Co3+ ion that was originally present in the sample. These H+ ions are titrated with 0.10-M ...
*October 26, 2014*

**math**

all the seats in two sections of a movie theater are occupied. in one section there are 8 row with 18 seats in each row.
*October 26, 2014*

**Math**

Can someone please check these problems? Thank you! Solve each equation for the indicated value. 1. a-b=-c, for a I got a=-c+b 2. 4y+6x=12, for y I got y=-3/2x+3
*October 26, 2014*

**Chemistry**

The combustion of propane and oxygen produces carbon dioxide and water. What mass of water is produced from the combustion of 10.4g of propane, C3H8
*October 26, 2014*

**Math**

Thank you so much
*October 26, 2014*

**Math**

Find the exact interest on a loan of $32,400 at 7% annually for 30 days.
*October 26, 2014*

**social studies**

why did Deganawida think it was important to stop fighting?
*October 26, 2014*

**Chemistry**

Find the enthalpy change of the following reactions 2C+2H2O---> CO2+CH4 Using the following reactions with their change in H values. C+H2O---->CO+H2 H=+131.1kjmol-1 Co+H2O---->CO2+H2. H=-41.2kjmol-1 CH4+H2O--->CO+3H2 H=15.3
*October 26, 2014*

**Chemistry**

Find the enthalpy change of the following reactions 2C+2H2O---> CO2+CH4 Using the following reactions with their change in H values. C+H2O---->CO+H2 H=+131.1kjmol-1 Co+H2O---->CO2+H2. H=-41.2kjmol-1 CH4+H2O--->CO+3H2 H=15.3
*October 26, 2014*

**physics**

If an object is initially moving with a constant velocity of 20m/s towards positive x-axis and after 5 sec it changes its direction and moving at an angle of 30o with x-axis, find magnitude and direction of its acceleration.
*October 26, 2014*

**chemistry**

The reaction of 2.5 mol of O2 with 4.6 mol of C3H8 will produce ________ mol of H2O.
*October 26, 2014*

**Physics**

A cannon ball is fired horizontally with velocity of 15m from the top of a cliff 90m high.after how many seconds will it hit the foot of the cliff(a)time (b)at what distance from the foot of the cliff will it strike.
*October 25, 2014*

**Physical Education help**

The body's reaction to information is to send these to the brain. A. Neurons B. Impulses C. Dendrites D. Synapse Is the answer B? Thank you
*October 25, 2014*

**Physical Education help**

Thank you :)
*October 25, 2014*

**Physical Education help**

When diving into water, it is important to look before diving to avoid (blank) that could damage your nervous system. A. Deep water B. Underwater hazards C. Living creatures D. Water toys Is the answer B? Thanks
*October 25, 2014*

**Physical Education help**

Thank you Ms. Sue!
*October 25, 2014*

**Physical Education help**

The part of the brain that controls movement and balance is the A. Cerbrum B. Cerebellum C. Brain stem D. Frontal lobe Is the answer B? Thanks
*October 25, 2014*

**Economy, management, corporate governance**

BOB'S SUPERMARKET: COMPETING WITH THE BIG BOYS
*October 25, 2014*

**Math**

The data shows the total number of employee medical leave days taken for on-the-job accidents in the first six months of the year: 16, 7, 23, 9, 25, 16. Find the standard deviation.
*October 25, 2014*

**Science HELP!**

When diving into water, it is important to look before diving to avoid (blank)damage your nervous system. A. Deep water B. Underwater hazards C. living creatures D. Water toys Is the answer B? Thanks
*October 25, 2014*

**Science HELP!**

The part of the brain that controls movement and balance is the A. Cerbrum B. Cerebellum C. Brain stem D. Frontal lobe Is the answer B? Thanks
*October 25, 2014*

**math**

Thanks so much
*October 25, 2014*

**math**

8x-1=55
*October 25, 2014*

**Science HELP!**

The body's reaction to information is to send these to the brain. A. Neurons B. Impulses C. Dendrites D. Synapse Is the answer B? Thanks
*October 25, 2014*

**8th grade; English**

c b d c, tell me which ones are wrong and give me the answers to them
*October 25, 2014*

**Math**

Im still confused on how to solve these equations for the indicated value. 1. a-b=-c, for a 2. y=1/2x-10, for x
*October 25, 2014*

**Fundamental engineering principles **

A car traveling at 108 km hr-1 deceleration uniformly from 108 km hr-1 to 72 km hr-1whilst covering 200m.it continues at this reduced for 150m before slowing down uniformly to rest over a distance of 225m. Draw the velocity-time diagram and use it to determine: (A)the total ...
*October 25, 2014*

**Calculus/pre-trig**

Write the formula for the discriminant. State the types of roots for a quadratic equation, explaining how the discriminant helps you determine the type.
*October 25, 2014*

**Math**

How do you solve each of these equations for the indicated value? I'm so confused on how to do it 1. a-b=-c, for a 2. 4y+6x=12, for y 3. y=1/2x-10, for x
*October 25, 2014*

**Math**

a) One mould forms a sculpture that is a composite object comprising a right cylinder with base diameter 15 in. and height 3 in., and a right cone with the same base diameter as the base of the cylinder and a height of 9 in. Determine the volume of the sculpture to the nearest...
*October 25, 2014*

**Precalculus**

A cruise ship sets a course N50°E from an island to a port on the mainland, which is c = 170 miles away. After moving through strong currents, the ship is off course at a position P that is N36°E and a = 90 miles from the island, as illustrated in the figure. (a) ...
*October 25, 2014*

**Math**

An igloo approximates a hemisphere, with an entrance tunnel that approximates half a right cylinder. The base of the igloo has diameter 4.0 m. The entrance is 0.8 m long; it has an external radius of 0.8 m and an internal radius of 0.7 m. Calculate the surface area of the ...
*October 25, 2014*

**Math**

f(x)=3x^2-x-2 If x=2, what is f(x)? What point is on the graph of f? For the first question, I got 8. But, I'm having trouble understanding the second question.
*October 25, 2014*

**Pre-Calc/Trig**

Yes, its correct.
*October 25, 2014*

**Math**

A solid sphere just fits inside a cube that has an edge length equal to the diameter of the sphere. The edge length of the cube is 5.8 cm. What is the volume of air in the cube to the nearest cubic centimetre?
*October 25, 2014*

**math**

1/64
*October 25, 2014*

**math**

i really dont know can you please tell me the correct one 4.1/16 5.1/4
*October 25, 2014*

**Precalculus**

39 + 21 + 39= 99
*October 25, 2014*

**Precalculus**

A reconnaissance airplane P, flying at 11,000 feet above a point R on the surface of the water, spots a submarine S at an angle of depression of β = 21° and a tanker T at an angle of depression of α = 39°, as shown in the figure. In addition, ∠SPT is ...
*October 25, 2014*

**Pre-Calc/Trig**

oh wait, nvm
*October 25, 2014*

**Pre-Calc/Trig**

oh okay thank you, do i plug them in now or leave it at that?
*October 25, 2014*

**Precalculus**

The rectangular box shown in the figure has dimensions 10" × 7" × 3" (a = 10, b = 7, c = 3). Approximate the angle θ formed by a diagonal of the base and a diagonal of the 7" × 3" side. (Round your answer to two decimal places.)
*October 25, 2014*

**Lauren**

Let f(x) = 3+4x-x^{3}. Find the open intervals on which f is increasing (decreasing). Then determine the x-coordinates of all relative maxima (minima). 1. f is increasing on the intervals 2. f is decreasing on the intervals
*October 25, 2014*

**math**

Let f(x) = 3+4x-x^{3}. Find the open intervals on which f is increasing (decreasing). Then determine the x-coordinates of all relative maxima (minima). 1. f is increasing on the intervals? 2. f is decreasing on the intervals?
*October 25, 2014*

**Precalculus**

An airplane flies 180 miles from point A in the direction 135° and then travels in the direction 240° for 90 miles. Approximately how far is the airplane from A? (Round your answer to the nearest whole number.)
*October 25, 2014*

**8th grade language arts**

Can you help me with it
*October 25, 2014*

**8th grade language arts**

i will tell u what i got and you tell me if it is correct a b c d
*October 25, 2014*

**physics**

A 20 g fridge magnet is being held onto the fridge by a 0.9 N force. coefficient of kinetic friction is 0.3 . (please include an FBD when giving the solutions) a. calculate the friction acting on the magnet. b. calculate the weight of the magnet c.the acceleration of the ...
*October 25, 2014*

**statistics**

For a normal distribution (symmetrical), a value that is two standard deviations below the mean would be closer to which of the following? Select one: a. 89th percentile b. Third Quartile c. Third percentile d. Median
*October 25, 2014*

**Algebra**

Line AB is parallel to line CD for A(4, -5), B(-2, -3), C(x, -2), D(6, y). Find a set of possible values for x and y.
*October 25, 2014*

**Physics**

A father pulls his son, whose mass is 27.3 kg and who is sitting on a swing with ropes of length 2.85 m, backward until the ropes make an angle of 36.8° with respect to the vertical. He then releases his son from rest. What is the speed of the son at the bottom of the ...
*October 24, 2014*

**Physics!**

A spring with a spring constant of 224.3 N/m is compressed by 0.253 m. Then a steel ball bearing of mass 0.0433 kg is put against the end of the spring, and the spring is released. What is the speed of the ball bearing right after it loses contact with the spring? (The ball ...
*October 24, 2014*

**Physics!**

A car of mass 1298.7 kg is moving at a speed of 64.0 mph when it misses a curve in the road and hits a bridge piling. If the car comes to rest in 0.234 s, how much average power (in watts) is expended in this interval?
*October 24, 2014*

**Physics**

If you are at the top of a toboggan run that is 44.3 m high, how fast will you be going at the bottom, provided you can ignore friction between the sled and the track?
*October 24, 2014*

**Physics**

A classmate throws a 1.1-kg book from a height of 1.3 m above the ground straight up into the air. The book reaches a maximum height of 4.0 m above the ground and begins to fall back. Assume that 1.3 m above the ground is the reference level for zero gravitational potential ...
*October 24, 2014*

**Physics**

A classmate throws a 1.1-kg book from a height of 1.3 m above the ground straight up into the air. The book reaches a maximum height of 4.0 m above the ground and begins to fall back. Assume that 1.3 m above the ground is the reference level for zero gravitational potential ...
*October 24, 2014*

**physics**

Calculate the mass of H2O produced by metabolism of 2.6kg of fat, assuming the fat consists entirely of tristearin (C57H110O6), a typical animal fat, and assuming that during metabolism, tristearin reacts with O2 to form only CO2 and H2O.
*October 24, 2014*

**SS**

How many airlines are owned by USA-based companies?
*October 24, 2014*

**Pre-Calc/Trig...**

Help me please Standard form: y=x^2-2x-3 Vertex form: ??? Intercept form: ???
*October 24, 2014*

**math**

I have 21 children in my class total. 6 of them are boys and 15 of them are girls. What is the percentage of males in the class
*October 24, 2014*

**algebra**

Ace car rental rents a car for $45 and .25 cents per mile. Star rental car rents a car for $35 and .30 cents per mile. How many miles would a driver need to drive before the cost of renting a car at these two places were the same?
*October 24, 2014*

**Civics PLEASE HELP ME!**

Thank you so much!! This will help me a lot!
*October 24, 2014*

**Civics PLEASE HELP ME!**

it is a breakup letter between the colonists and Great Britain. Please help?!
*October 24, 2014*

**Civics PLEASE HELP ME!**

Can anyone help me with a breakup letter for civics?? It is quite difficult for me. It is about the Declaration of Independence.
*October 24, 2014*

**math**

MRS SUE ANSWER MY QUESTION
*October 24, 2014*

**math**

MRS SUE ANSWER MY QUESTION
*October 24, 2014*

**math**

The answer is Idk and idc
*October 24, 2014*

**science**

thank you very much Ms.Sue
*October 24, 2014*

**science**

a horticultural wants a plant that produces flowers with a certain size color and fragrance but it now aware of any one plant having all of these traits. the quickest way she could achieve her goal would be to apply the process of_____________
*October 24, 2014*

**Math**

Interest is a concept familiar to most people: every credit card in existence has a term called annual percentage rate (APR), which is an interest rate. Suppose you charged $1,000 to a credit card that has a minimum payment each month equal to the interest owed. Can you figure...
*October 24, 2014*

**Physics**

As shown in the figure below, a skateboarder starts at point A on the ramp and rises to point B, a maximum height of h = 2.89 m above the top of the ramp. If the amount of work done against friction is insignificant, determine his initial speed at point A.
*October 24, 2014*

**Latin I**

Oh I found it.
*October 24, 2014*

**Latin I**

So would it be: The farmer and the woman showed the poet's farmhouse to the queen.
*October 24, 2014*

**people**

Which of the following conclusions is supported by the results of these studies
*October 24, 2014*

**Math**

There are two chords AB and AC in a circle.[AB]=10cm, [CD]=8cm and the radius of the circle is 12cm.what is the distance of each chord from the centre of the ccircle?
*October 24, 2014*

**Algebra**

(2a - b)^3 = 8a^3 - 8a^2b + 4ab^2 - b^3?
*October 24, 2014*

**matlab**

Find the maximum and minimum values of f( x,y)=2x^3+xy^2+5x^2+y^2
*October 24, 2014*

**chemistry**

You need 2.5 moles of aluminum for an experiment. How many atoms of aluminum is this?
*October 24, 2014*

**biology**

what is contracting subunit of skeletal muscle called
*October 23, 2014*

**statistics**

The physical plant at the main campus of a large state university recieves daily requests to replace florecent lightbulbs. The distribution of the number of daily requests is bell-shaped and has a mean of 46 and a standard deviation of 9. Using the empirical rule (as presented...
*October 23, 2014*

**Algebra**

How do I simplify (2a - b)(4a^2 - 2ab + b^2)? I keep getting 8a^3 - 8a^2b + 4ab^2 - b^3, but it shows wrong.
*October 23, 2014*

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