Friday

July 3, 2015

July 3, 2015

Total # Posts: 1,674

**Solar Energy Please Help**

@foxman thinks
*October 26, 2013*

**Mathhh**

Use substitution to solve the system of equations given below. 8x - 4y = 16 2x - y = 4
*October 25, 2013*

**science**

i think
*October 25, 2013*

**science**

destin y is rong
*October 25, 2013*

**science**

desiny isn't right
*October 25, 2013*

**Chemistry**

Help! If I have 0.0031 absorbance/sec, how would I convert this to absorbance/minute? Thanks
*October 22, 2013*

**calculus**

I really need help on this!!!!
*October 21, 2013*

**calculus**

Let y =x arcsin x, x is an element of ]-1, 1[. Show that d^2y/dx^2 = 2-x^2/(1-x^2)^3/2
*October 21, 2013*

**Math- Urgent**

2e = 4e -16 -4e -4e -2e=-16 /-2 /-2 e=8
*October 21, 2013*

**math**

x+4=-8 do you have to solve for x?
*October 21, 2013*

**math**

I completely forgot the rules but.... if you have ((1-x)^1/2)^2 Then would you multiply the exponents to get 2/2 = 1 or add them to get 3/2
*October 21, 2013*

**algebra**

2 cm. i think
*October 21, 2013*

**Math please help**

You have to set up a proportion. 2/3 = 12/x solve for x 2x=36 x=18
*October 21, 2013*

**algebra**

3. I think Because you take the total number of problems (48) and divide that by 2 = 24. Then divide that by 2 = 12. And divide that by 2= 6. And divide that by 2 = 3. He needs to complete 3 problems on the first day for the number of problems completed to double each day for ...
*October 21, 2013*

**math**

please help me. I don't know what I am doing wrong
*October 21, 2013*

**math**

I tried to use the quotient rule but I get stuck simplifying it. I got (sqrt1-x^2)(1/sqrt1-x^2) - (x+arcsinx)(1/2(1-x^2)2x) / (sqrt1-x^2)^2
*October 21, 2013*

**math**

*use the quotient rule
*October 21, 2013*

**math**

I get stuck on the second derivative, trying to get it to equal 2-x^2/(1-x^2)^3/2. I think that from my first derivative, you have to sure the quotient rule
*October 21, 2013*

**math**

xarcsinx*
*October 21, 2013*

**math**

Sorry i meant x arrsin x. So I thought the first derivative of that would be x/sqrt1-x^2 + arcsinx
*October 21, 2013*

**math**

Let y = arcsin x, x is an element of ]-1, 1[. Show that d^2y/dx^2 = 2-x^2/(1-x^2)^3/2
*October 21, 2013*

**math**

ok thank you.
*October 21, 2013*

**math**

do you just change all the signs of the terms? if so, why is this necessary?
*October 21, 2013*

**math**

Thanks. I was wondering, why is it "+ sin x" in the second step?
*October 21, 2013*

**math**

cos2x-sinx=0. Factor and solve for sinx
*October 21, 2013*

**Science help! URGENT. Check answers**

If anybody is still looking for the answers to this quiz, I got a 100 with these answers: 1. False 2. C 3. D 4. B 5. D 6. A 7. B 8. A On number 9, give an example in change of velocity. The change of velocity is known as acceleration, and it is the rate at which velocity ...
*October 21, 2013*

**physics**

Part b) is working forces. So you have centripetal acceleration = N-kx where kx is the spring force. cent acc = mv^2/r so us a)to derive this.
*October 19, 2013*

**physics**

Use this link it shows the question you are solving , but it has slightly different parameters ie the equilibrium of the spring. It show that you need GPE + EPE = KE + GPE + EPE ie TOP=SIDE. You can then rearrange this to get everything on one side except v (your speed). I ...
*October 19, 2013*

**physics**

Use this link it shows the question you are solving , but it has slightly different parameters ie the equilibrium of the spring. It show that you need GPE + EPE = KE + GPE + EPE ie TOP=SIDE. You can then rearrange this to get everything on one side except v (your speed).
*October 19, 2013*

**Can someone check these answer for me?**

The correct answers are 1. B 2. A 3. C 4. D 5. C I just took this and got 100%
*October 17, 2013*

**Solar Energy Help ASAP**

0.674 can someone help with the others quetion? Q4 5 6 7?
*October 17, 2013*

**ET3034TUx Solar Energy**

The current density of an ideal p-n junction under illumination can be described by: J(V)=Jph−J0(eqVkT−1) where Jph is the photo-current density, J0 the saturation-current density, q the elementary charge, V the voltage, k the Boltzmann's constant, and T the ...
*October 16, 2013*

**ET3034TUx Solar Energy**

The width of the space charge region at a p-n junction is reduced by applying a voltage bias over the p-n junction. What is the correct statement on both the bias voltage and the p-n junction? a)The voltage is a forward bias and the diffusion of the majority charge carriers ...
*October 16, 2013*

**Science help! URGENT. Check answers**

'somemone' is wrong because acceleration is the rate at which velocity changes, and the change can be speed, direction, or both and the eagle is constantly changing direction. The answers the asker chose are correct.
*October 15, 2013*

**Physics**

oscillating block ans D) 1.2
*October 15, 2013*

**Physics**

When you push down on the handle of a bicycle pump, a piston in the pump cylinder compresses the air inside the cylinder. When the pressure in the cylinder is greater than the pressure inside the inner tube to which the pump is attached, air begins to flow from the pump to the...
*October 15, 2013*

**Physics**

A sample of a monatomic ideal gas is originally at 20 °C. Calculate its final temperature of the gas if the pressure is doubled and volume is reduced to one-fourth its initial value.
*October 15, 2013*

**Science **

Humans developed antibiotics to fight bacterial infections. However, some antibiotics are no longer efective in killing the bacteria they once killed. How does the theory of evolution explain this?
*October 14, 2013*

**physics**

A 660 kg car is being pushed along a flat parking lot at a constant speed of 1.52 m/s. The coefficient of friction between the road and the car is 0.31. What force is being used to push the car?
*October 13, 2013*

**Quantum Physics**

Wrong !!!! I try it!!
*October 12, 2013*

**Quantum Physics**

Ive checked and its neither phi=2bt nor 2b
*October 12, 2013*

**Quantum Physics**

Q 7 and 8 Please!!!
*October 12, 2013*

**Quantum Physics**

3b - C 3c - 0
*October 12, 2013*

**Chemistry**

12.111111111
*October 12, 2013*

**physics**

Consider an ideal spring that has an unstretched length l0 = 3.9 m. Assume the spring has a constant k = 20 N/m. Suppose the spring is attached to a mass m = 6 kg that lies on a horizontal frictionless surface. The spring-mass system is compressed a distance of x0 = 1.7 m from...
*October 11, 2013*

**Physics**

A conical pendulum is constructed from a rope of length l and negligible mass, which is suspended from a fixed pivot attached to the ceiling. A small ball of mass m is attached to the lower end of the rope. The ball moves in a circle with constant speed in the horizontal plane...
*October 10, 2013*

**Science**

These answers are correct. 1. B 2. B 3. B 4. A - True
*October 8, 2013*

**reading**

TKU :)
*October 8, 2013*

**reading**

How is grandmother's dream different from reality? >Last night I dreamed of an old lover I had not seen him in forty years. When I awoke, I saw him on the street. His hair was white, his back was stooped. How could I say hello? He would have puzzled all day about who ...
*October 8, 2013*

**Physics**

A person is standing on the edge of a cliff of height h= 24 m. She throws a stone of mass m=0.2 kg vertically down with speed v0= 10 m/s (stone 1) and another stone of the same mass vertically up at the same speed (stone 2). The gravitational acceleration is g=10 m/s2. (a) ...
*October 6, 2013*

**physics**

We are standing at a distance d=15 m away from a house. The house wall is h=6 m high and the roof has an inclination angle β=30 ∘. We throw a stone with initial speed v0=20 m/s at an angle α= 35 ∘. The gravitational acceleration is g=10 m/s2. (See figure...
*October 6, 2013*

**physics**

We are standing at a distance d=15 m away from a house. The house wall is h=6 m high and the roof has an inclination angle β=30 ∘. We throw a stone with initial speed v0=20 m/s at an angle α= 35 ∘. The gravitational acceleration is g=10 m/s2. (See figure...
*October 6, 2013*

**physics**

An elevator is stopped at the ground floor. It starts moving upwards at constant acceleration a>0 for 5 seconds. It then keeps a constant speed for 35 seconds. Finally, it slows down with an acceleration of the same magnitude (but opposite direction) −a , until it ...
*October 5, 2013*

**physics**

An elevator is stopped at the ground floor. It starts moving upwards at constant acceleration a>0 for 5 seconds. It then keeps a constant speed for 35 seconds. Finally, it slows down with an acceleration of the same magnitude (but opposite direction) −a , until it ...
*October 5, 2013*

**physics**

We are standing at a distance d=15 m away from a house. The house wall is h=6 m high and the roof has an inclination angle β=30 ∘. We throw a stone with initial speed v0=20 m/s at an angle α= 35 ∘. The gravitational acceleration is g=10 m/s2. (See figure...
*October 5, 2013*

**physics (it's rather urgent help is appreciated**

no
*October 5, 2013*

**physics (it's rather urgent help is appreciated**

yeah
*October 5, 2013*

**physics (it's rather urgent help is appreciated**

@ss01 for the inclined wall stone throw
*October 5, 2013*

**physics (it's rather urgent help is appreciated**

@ss01 did you manage to find the time?
*October 5, 2013*

**physics**

i can't quite get the value of t
*October 5, 2013*

**physics**

thank you so much, sorry for being rather spamy so to say
*October 5, 2013*

**physics (it's rather urgent help is appreciated**

We are standing at a distance d=15 m away from a house. The house wall is h=6 m high and the roof has an inclination angle β=30 ∘. We throw a stone with initial speed v0=20 m/s at an angle α= 35 ∘. The gravitational acceleration is g=10 m/s2. (See figure...
*October 5, 2013*

**Chemistry**

Calculate the magnitude of the cohesive energy of potassium iodide (KI). The ionic radii of K+ and I−, are 152 pm and 206 pm, respectively. Assume the Born exponent n is 10. Assume a Madelung constant of 1.7. Please report your answer in kJ/mol or how to calculate it.
*September 28, 2013*

**Chemistry**

Calculate the magnitude of the cohesive energy of potassium iodide (KI). The ionic radii of K+ and I−, are 152 pm and 206 pm, respectively. Assume the Born exponent n is 10. Assume a Madelung constant of 1.7. Please report your answer in kJ/mol or how to calculate it.
*September 28, 2013*

**Bio/Math**

A population of glasswing butterflies exhibits logistic growth. The carrying capacity of the population is 200 butterflies, and rmax, the maximum per capita growth rate, of the population is 0.10 butterflies/(butterflies*month). Calculate the maximum population growth rate for...
*September 22, 2013*

**AP Bio; PLEASE HELP!**

if a fish farmer wanted to harvest his fish so that it recovered at the maximum rate, where should the population be maintained? There is a graph number of weeks vs. numbers of fish. and A B C and D marked on the graph. How do I figure it out??
*September 22, 2013*

**Chemistry**

Finally I found it.We have to do this : wavelength=h/P P^2=2*m*E P=sqrt(2*m*E) E = joule h = Planck's constant m = kg
*September 18, 2013*

**Chemistry**

Can you write the result because i found 5.067e-7 and it's wrong.I try it many time in diffrent ways baut I finished with the some result!
*September 18, 2013*

**Chemistry**

Calculate the wavelength of a proton with energy 2.45 eV. Please some help!
*September 18, 2013*

**Classical Mechanics**

thank you it help me!
*September 18, 2013*

**Classical Mechanics**

Mary wants to throw a can straight up into the air and then hit it with a second can. She wants the collision to occur at height h=5.0 m above the throw point. In addition, she knows that she needs t1=4.0 s between successive throws. Assuming that she throws both cans with the...
*September 18, 2013*

**Chemistry**

Calculate the wavelength of a proton with energy 2.45 eV.
*September 15, 2013*

**BIOLOGY**

yes, no, yes is correct
*September 12, 2013*

**science**

Green algae grow in the fur of the South American sloth. The green algae provide camouflage for this tree-doweling mammal, and from the fur and skin of the sloth the algae obtain moisture. A moth also lives in the fur. The moth larvae provide waste material used by the algae ...
*September 11, 2013*

**Social studies**

then 4
*September 10, 2013*

**Social studies**

Which of the following "best" illustrates how a President can use the news media to reach the largest segment of the public? 1) hold a state dinner for foreign dignities 2) hold a conference Cabinet members 3) meet with head of Congressional committees 4) give speech...
*September 10, 2013*

**Social studies**

Suppose the president vetoed a bill passed by Congress. According to the information, which of the following actions by Congress would most likely ensure that the bill will become? 1) let the veto stand 2) reintroduce the same legislation 3) try to override the veto with a two...
*September 10, 2013*

**social studies**

I think it's (2). Is it correct?
*September 8, 2013*

**social studies**

A 150 years ago nearly 3/4 of the working people in this country worked on farms. By the beginning of the 1980s only 1/40 did. Clearly automation "destroyed" many farms jobs. But if technology were really eliminating work, we would expect unemployment . The reason ...
*September 8, 2013*

**social studies**

I'm kind indecisive on first question (either answer: 1 or 3)
*September 8, 2013*

**social studies**

Question 1: I have (5) Question 2: I have (c) 2>>Based on the result of the studies, what should an elementary teacher do to unsure that a child with an unusual name develops normal intellectual ability? a- Make a special effort to ignore the child b- Try to give the ...
*September 8, 2013*

**social studies**

Does having an unusual name, such as Chastity, Englebert or Moon unit, have an effect on how a child develops? The results of some previous studies agrees with the commonsense idea that such as name could cause a child to be rejected or ridiculed and thus could have a negative...
*September 8, 2013*

**social studies**

When choosing a name for a child, how could a parent best use this study to help ensure the child's normal social development? 1 keep in mind that other characteristics are more important than name 2try not to choose an ethnic name 3Consider an unusual name because it will...
*September 8, 2013*

**Quantum physics**

@ Lord The circuit is a phase change (Z) with a Hadamard (H); plug in the eqn (simple arithmetic if u understand the material) TY for ans tho, wish i knew how u arrived to it, i wrote out all the y's and i couldnt figure out s
*September 8, 2013*

**Quantum physics**

ANS TO 3 IS c WATS Q10?
*September 8, 2013*

**Quantum physics**

7)A) I,H 7)B) X,H
*September 8, 2013*

**Quantum physics**

Someone give me Q3 and I give him/her all the others questions!
*September 8, 2013*

**Quantum physics**

any1 got the ans to q 10?
*September 8, 2013*

**Quantum physics**

Hey can any1 help me with question 10, on my last try, i cant seem to figure it out
*September 7, 2013*

**Quantum physics**

Ans to q2 above, i can help with the other 2q's
*September 7, 2013*

**Math**

Find the derivative of y=sin(x)*(sinx+cosx)
*September 4, 2013*

**AP Calc**

How do you find the derivative of y=sin(x)*(sinx+cosx)
*September 4, 2013*

**AP Calc**

Find the equation of the tangent line at the indicated point. y=5th root of (3x^3+4x) at (2,2)
*September 4, 2013*

**Biology**

You are testing a hypothesis that population density of a particular plant species influences the rate at which a pathogenic fungus infects the plant. Because the fungus causes visible scars on the leaves, you can easily determine whether a plant is infected. Design an ...
*August 26, 2013*

**8th Grade Math**

cancel out the denominator by multiplying by greatest common factor so 2. 2(5/2t-t)=2(3+3/2t) so now equation is 5t-2t=6+3t then solve. 3t=6+3t you should get no solution
*August 26, 2013*

**thermodynamics**

Use the Gibbs Free Energy Equation: ^G=^H-T^S ;where ^ represents Delta. Plug in the values and you are done! Remember to convert 25C to Kelvin.
*August 25, 2013*

**physics**

Use Couloumb's law: F=q1q2/d^2 We get force is inversely proportional to the square of the distance. Solve the rest yourself.
*August 24, 2013*

**math**

Which situation can be modeled by tossing a coin three times? a. choosing which one of sixteen teams will win a tournament c. selecting a desk from thirty-six in a classroom b. deciding which English teacher of eight will win a trip to London d. picking one of six math teachers
*August 17, 2013*

**Math**

so b?
*August 17, 2013*

**Math**

cause i dont understand what you saying
*August 17, 2013*