Sunday

January 22, 2017
Total # Posts: 1,439

**Chemistry**

Free-energy change, ΔG∘, is related to cell potential, E∘, by the equation ΔG∘=−nFE∘ where n is the number of moles of electrons transferred and F=96,500C/(mol e−) is the Faraday constant. When E∘ is measured in volts, Δ...

*May 18, 2014*

**Chemistry**

Suppose a patient is given 140mg of I−131, a beta emitter with a half-life of 8.0 days. Assuming that none of the I−131 is eliminated from the person's body in the first 4.0 hours of treatment, what is the exposure (in Ci) during those first four hours? Express...

*May 14, 2014*

**Chemistry**

Suppose a patient is given 140mg of I−131, a beta emitter with a half-life of 8.0 days. Assuming that none of the I−131 is eliminated from the person's body in the first 4.0 hours of treatment, what is the exposure (in Ci) during those first four hours? Express...

*May 14, 2014*

**Physics**

A daredevil performs a stunt in which he jumps with his motorcycle from a horizontal cliff 10m high. What must the initial velocity of the motorcycle be, in order for the stuntman to barely clear a 10m wide water canal at the base of the cliff?

*May 8, 2014*

**Physics**

A little girl is standing on a cliff and throws a ball straight down at a speed of 5m/s towards the ground below. How far has it fallen 2.0 seconds after it leaves her hand?

*May 8, 2014*

**Physics**

A ball leaves a table with an initial horizontal velocity of 2.4m/s. The height of the table is adjustable. In two runs, the height of the table is set at 2.5m and 5.0m respectively. Assume air resistance is negligible. What is the horizontal distance between the two landing ...

*May 8, 2014*

**calculus help**

Find the derivative of the function. y = integral from cosx to sinx (ln(8+3v)) dv lower limit = cosx upper limit = sinx y'(x) = ????

*May 7, 2014*

**Physics/Calculus**

It takes a force of 21,714lb to compress a coil spring assembly on a New York City Transit Authority subway car from its height of 8in to its fully compressed height of 5in. A. What is the assemblys force constant? B. How much work does it take to compress the assembly the ...

*May 2, 2014*

**Calculus/Physics**

A spring has a natural length of 10in. An 800lb force stretches the spring to 14in. A. Find the force constant B. How much work is done in stretching the spring from 10 to 12 inches? C. How far beyond its natural length will a 1600lb force stretch the spring.

*May 2, 2014*

**Calculus/Physics**

It took 1800J of work to stretch a spring from its natural length of 2m to a length of 5m. Find the spring's force constant.

*May 2, 2014*

**science**

^ get rekt

*May 1, 2014*

**Physics MCQ - Quick check**

Thanks Damon

*April 28, 2014*

**Calculus**

The following are about an infinite region in the 1st quadrant between y=e^-x and the x-axis. B)Find the volume of the solid generated by revolving the region about the y-axis Part A was solved below. Does anyone know how to do Part B?

*April 27, 2014*

**Calculus**

Thank you. What about part B?

*April 27, 2014*

**Calculus**

The following are about an infinite region in the 1st quadrant between y=e^-x and the x-axis. A) Find the area of the region B)Find the volume of the solid generated by revolving the region about the y-axis

*April 27, 2014*

**Calculus**

Limit as x approaches 0 of x(1-cosx)/t-sinx. Confused on how to get this answer.

*April 21, 2014*

**Calculus**

Determine the behavior of limits A. Limit as x approaches 1 of: (log x)/((x-1)^2) B. Limit as x approaches infinity of: ((x-1)^2)/(log x))

*April 21, 2014*

**Calculus**

Thanks

*April 21, 2014*

**Calculus**

Evaluate limit as x approaches 0 of: csc^2(7x)tan(2x^2)

*April 21, 2014*

**CHEMISTRY HELP !!!!**

As a standard voltaic cell runs, it "discharges" and the cell potential decreases with time. Explain.

*April 19, 2014*

**Calculus Help!!!!!**

sketch the graph of the following. Show all your work and include all the important points and asymptotes. also find y' and y'' ? y= (x^3)/(x+1)^2

*April 16, 2014*

**Physics**

A "reference ring" with moment of inertia Ic rests on a solid disk torsion pendulum with a moment of inertia I0. a) What is the period T0 for the motion with the disk alone? b) What is the period T1 for motion with the combined system? c) Use the expressions from a) ...

*April 14, 2014*

**algebra**

solve the following: 300e^.06x = 1500

*April 11, 2014*

**algebra**

Evaluate: log base 5 379

*April 11, 2014*

**CHEMISTRY HELP !!!! Check**

using Kb, for NH3 (from Appendix E), calculate Ka for the NH4+ ion. Kb for NH3 is 1.81 x 10^-5 Ka for NH4+ is Kw / Kb = 10^-14 / 1.81 x 10^-5 = 5.52 x 10^-10

*April 10, 2014*

**Calculus Help Please!!! Urgent!!!**

If x^3 - y^3 =3 , use only implicit diff. to find d^2y/dx^2 . Express your answer in terms of x and y only and write is as a proper fraction that is completely simplified as much as possible. d^2y/dx^2= -6x/y^5 (this is the answer I should get but i don't know how to show ...

*April 9, 2014*

**Calculus Help Please!!!**

A stone is dropped into a lake, creating a circular ripple that travels outward at a speed of 40 cm/s. Find the rate at which the area within the circle is increasing after each of the following. after 1 s = after 3 s = after 7 s =

*April 2, 2014*

**Calculus Help Please!!!**

Consider the following. f(x) = 8x (square root of (x − x^2)) (a) Use a graph to find the absolute maximum and minimum values of the function to two decimal places.

*April 1, 2014*

**Damon**

The question was like this!

*March 30, 2014*

**Calculus Help Please!!!**

Verify the given linear approximation at a = 0. Then determine the values of x for which the linear approximation is accurate to within 0.1. (Enter your answer using interval notation. Round your answers to three decimal places.) ln(1 + x) ≈ x xE

*March 30, 2014*

**Physics**

Two pucks with similar masses collide with each other over a nearly frictionless surface. At the moment of collision, a sharp knocking sound is produced. Is this collision elastic or inelastic? Explain.

*March 30, 2014*

**Physics**

Consider an isolated system consisting of two masses, each of which has a velocity vector in two dimensions. When these two masses collide the total momentum of the system is conserved. (a) Show that if the total momentum of the system is conserved then the component momenta ...

*March 30, 2014*

**algebra**

The monthly cost of driving a car depends on the number of miles driven. Lynn found that in May her driving cost was $310 for 140 mi and in June her cost was $450 for 700 mi. Assume that there is a linear relationship between the monthly cost C of driving a car and the ...

*March 29, 2014*

**Physics**

A 4700 kg vehicle on a level surface experiences a force applied due to the engine of 3700 N forward. If the force of friction acting on the vehicle is 189 N backward: Determine the values of the other forces acting on the vehicle. Draw a free body diagram and determine the ...

*March 20, 2014*

**CALCULUS HELP**

Let r(x)= f(g(h(x))), where h(1)=4, g(4)=5, h'(1)=3 , g'(4)=5 and f'(5)=7. find r'(1).

*March 20, 2014*

**Calculus Help**

Use logarithmic differentiation to find the derivative of the function. show steps please! y=(e^-xcos^2(x))/(x^2+x+1)

*March 16, 2014*

**Calc**

I was trying to solve the same question and couldn't find the domain. if someone can help me with it, I will be thankful.

*March 16, 2014*

**Calc**

what is the domain?

*March 16, 2014*

**Calculus**

Find equations of both the tangent lines to the ellipse x^2 + 4y^2 = 36 that pass through the point (12, 3). smaller slope y= larger slope y=

*March 14, 2014*

**Physics**

Assume a spring has an un-stretched length Xo. Write an expression for the elastic potential energy of the spring in terms of the position of the end of the spring X and its spring constant K.

*March 14, 2014*

**Physics**

Assume a spring has an un-stretched length Xo. Write an expression for the elastic potential energy of the spring in terms of the position of the end of the spring x and its spring constant k.

*March 13, 2014*

**Physics**

Consider the gravitational potential, kinetic, and total mechanical energies of a cart moving down an inclined ramp. (Also, let gravitational potential energy be defined to be zero when the cart is at the bottom of the ramp. A. Write an expression for the gravitational ...

*March 13, 2014*

**Calculus**

Find all points on the graph of the function f(x) = 2 cos x + cos^2 x at which the tangent line is horizontal. (Use n as your arbitrary integer.) smaller y-value (x,y)= larger y-value (x,y)=

*March 9, 2014*

**Math**

What is an equation for the line that passes through points(4,-4) and (8-4)?

*March 9, 2014*

**Calculus Help**

Find a parabola with equation y = ax^2 + bx + c that has slope 6 at x = 1, slope −14 at x = −1, and passes through the point (2, 17).

*March 7, 2014*

**Algebra word problems**

You have a total of $175 in $5 and $20 bills. The number of $5 bills you have is 3 more than 4 times the number of $20 bills. How many of each type of bill do you have?

*March 6, 2014*

**math 2**

255

*March 6, 2014*

**Physics**

COULD I GET SOME HELP?

*March 3, 2014*

**Physics**

A dynamics cart with a friction pad is placed at the top of an inclined track and released from rest. The cart accelerates down the incline at a rate of .60m/s^2. If the track is angled at 10 degrees above the horizontal, determine the coefficient of kinetic friction between ...

*March 3, 2014*

**Physics**

A baseball player rounds third base and is heading for home when he is signaled by the base coach to slide. The player has a speed of 3.5m/s when he begins to slide and he travels through a linear distance of 1.50 meters before coming to rest. Determine the coefficient of ...

*March 3, 2014*

**Calculus Help**

Let P(t) be the percentage of Americans under the age of 18 at time t. The table gives values of this function in census years from 1950 to 2000. (I didn't put the table here because it will not display well so the table has basically t as time from 1950 to 2000 and P(t) ...

*March 2, 2014*

**Calc Help Please**

I did some of them so can you help me with the rest. Consider the piecewise functon f(x) = (4x^2-3)/(3x^2-15) x<(-2) square root of(4-x^2) (-2)<-x<-(2) 5 x>2 lim x->-2^- f(x)= ?????? lim x->-2^+ f(x)= 0 f(-2)= 0 f(4) = 5 list the values of x for which f(x) is...

*February 28, 2014*

**Math**

the smallest regulation golf ball has a volume of 2.48 cubic inches. if the diameter of the ball were increased by 10%, or a factor of 1.1, what will the volume of the golf ball be?

*February 27, 2014*

**Philosophy( Please Help Me))**

Hi, can someone please tell me whether or not I have choose the correct answer for these three questions. 1. According to Gilligan, which of the following best describes male thinking? a. Males adopt a personal way of relating to moral issues. b. Males adopt an abstract way of...

*February 27, 2014*

**Calculus**

the correct answer I was given has a negative 1/3 before the log. Also, how did you get the 1/3 value?

*February 24, 2014*

**Calculus**

Evaluate the integral: (cos(2-3x) - tan(5-3x))dx

*February 24, 2014*

**Physics**

Assume that you take data on the projectile range for a variety of different launch angles A at a fixed initial velocity Vo. You would like to plot your data to see if the range formula discussed in the introduction is supported by the data. The easiest way to do this is to ...

*February 17, 2014*

**Physics**

For a given initial projectile speed, you observe that the projectile has a certain range R at a launch angle A = 30 degrees. For what other launch angle will the projectile have the same range (assuming the same initial projectile speed)? Without the use of mathematical ...

*February 17, 2014*

**Physics**

For a given initial projectile speed Vo, calculate what launch angle A gives the longest range R. Show your work, don't just quote a number.

*February 17, 2014*

**4th grade math**

36 kg

*February 10, 2014*

**Physics**

Make a predictive statement about the path dependence of accelerations due to gravity

*February 10, 2014*

**Physics**

Calculate the time it would take for an object to fall through a linear height equal to the objects starting height, h for a 20 degree incline.

*February 10, 2014*

**Physics**

An object begins at rest on a frictionless inclined plane at a linear distance of 2.0m from the base of the incline. If the incline makes an angle of 20 degrees with the horizontal, determine the time it will take for the object to reach the base of the incline.

*February 10, 2014*

**Physics**

Thanks for the help. It is much appreciated!

*February 3, 2014*

**Physics**

A small washer is taped to a golf ball and the ball is hung from an electromagnet. When a trigger is activated the electromagnet will shut off and the golf ball will fall through a height of 75 cm to land on a time of flight pad. Determine the amount of time it will take for ...

*February 3, 2014*

**Physics**

An object at rest accelerates through a distance of 1.5 m at which point the instantaneous velocity of the object is 3.5m/s. Determine: a. The average acceleration of the object b. The time it took the object to travel 1.5m c. The average velocity of the object during this ...

*February 3, 2014*

**maths**

One pump fills a tank two times as fast as another pump. If the pumps work together they fill the tank in 18 minutes. How long does it take each pump working alone to fill the tank?

*February 2, 2014*

**physics**

A car is being pulled out of the mud by two forces that are applied by the two ropes shown in the drawing. The dashed line in the drawing bisects the 30.0° angle. The magnitude of the force applied by each rope is 2900 newtons (N). (a) How much force would a single rope ...

*January 27, 2014*

**maths**

A coin box contained some twenty-cent and fifty-cent coins in the ratio 4 : 3. After 20 twenty-cent coins were taken out to exchange for fifty-cents coins of the same value and put back in the box, the ratio of the number of twenty-cent coins to the number of fifty-cents coins...

*January 27, 2014*

**Maths**

Thanks Steve. Where is 12 come from?

*January 27, 2014*

**Maths**

Daniel's watering can holds 6L of water when full. He fills his watering can 3 times from the bucket and then the bucket is empty. How much more waterdoes one full bucket hold than Daniel's full watering can? A 3L B 9L C 12L D 18L

*January 27, 2014*

**MATHS**

Ken had three times as many apples as papayas. After selling 160 apples and 25 papayas, he had twice as many papayas as apples left. How many fruits did he have at first?

*January 27, 2014*

**MATH**

Mrs Lim is 41 years old and her daughter is 14 years old. How many years ago was Mrs Lim four times as old as her daughter?

*January 26, 2014*

**business**

Tim Urban, owner/manager of Urban's Motor Court in Key West, is considering outsourcing the daily room cleanup for his motel to Duffy's Maid Service. Tim rents an average of 50 rooms for each of 365 nights (365 X 50 equals the total rooms rented for the year(. Tim'...

*January 22, 2014*

**Chemistry**

1.42e9 2.36e-10

*December 21, 2013*

**math**

a dealer has 30 cars and trucks. If 2 more cars are delivered, the dealer will have 3 times as many cars as trucks. How many trucks does the dealer presently have?

*December 14, 2013*

**physics**

a .2 kg ball is being swung around a verticle circle from a 1 m long string, the ball is traveling at 4 m/s counter -clockwise. what is the tension on the string?

*December 8, 2013*

**science**

If an automobile engine delivers 40.2 hp of power, how much time will it take for the engine to do 5.90 ✕ 105 J of work? (Hint: Note that one horsepower, 1 hp, is equal to 746 watts.)

*December 3, 2013*

**4th Grade Math: Help Is Needed ASAP**

My son is in the fourth grade and is needing help with these math problems. Can someone please help him with these problems. 1. 2/3+2/9= 2. 3/5+3/10= 3. 5/12+1/3= 4. Find the sum of 1/6 and 1/12 5. Add 1/4 to the answer in Exercise 4. 6. What is the sum of 1/8, 1/4, and 3/8? 7...

*November 18, 2013*

**TO ANY MATH HELPERS**

1) x= -.5 y= -.5 2) x=.5 y=5

*November 18, 2013*

**English**

Zach used to work at an independent record label. Negotiating could be exciting, but he was supposed to slant everything in the label’s favor. Some reps used questionable tactics. He couldn’t look at himself in the mirror if he treated people like that. First ...

*November 18, 2013*

**English**

When the servers arrived, Jack gave them the information on today's specials. He talked enthusiastically about the fresh berries: "They look fantastic! I want to serve them with shortcake." 1. In the above passage, "talked" is an example of a(n): a)...

*November 18, 2013*

**Math 5th grade**

Thank you Ms. Sue!

*November 11, 2013*

**Math 5th grade**

1. 16/40, 24/60 2. 24/30, 36/45 3. 24/40, 36/60

*November 11, 2013*

**Math 5th grade**

write two fractions that are equivalent to each fraction. 1. 8/20 2. 12/15 3. 12/20 Can u please show me

*November 11, 2013*

**Math 5th grade**

Write two fractions that are equivalent to each fraction. 1. 2/5 2. 21/35

*November 11, 2013*

**3rd grade Math**

3 by 4

*November 4, 2013*

**English... Urgent**

Hi this is a mystery problem can you solve this? The best forger of all time was indeed a most brilliant artist and a man respected and sought after in the criminal world. One day he was asked to copy $50 notes but the police searched his premises before be even got started ...

*October 26, 2013*

**English... Urgent**

Look at the following puzzles and try to decipher the well known sayings 1. Ban ana 2.nafish nafish 3.japmadean 4.issue issue issue issue issue issue issue issue issue issue 5. Lookuleap Note that I have not typed any of these words wrong

*October 26, 2013*

**Algebra II**

Having trouble solving this... Write the equation if a line that goes through (6,-1/2) and has an x-intercept of 5x-2y=-20 I think the x-intercept is -4, but I don't know what to do with that.

*October 24, 2013*

**physics**

Ok so im looking for minimum avg power for a 38 kg boy to climb a 170 m building that takes 10.2 min include only work done against gravity

*October 14, 2013*

**English**

Hi this is a rebus can you answer it? ECNALG

*October 12, 2013*

**English**

Hi this is a rebus question, can you answer it? ECNALG

*October 12, 2013*

**English**

Hi this a rebus, can you answer it? TEEXAMRM

*October 12, 2013*

**English**

Hi this is a rebus, can you answer it? KNEE LIGHT

*October 12, 2013*

**economics**

According to the permanent income hypothesis, households will tend to react to a temporary tax cut by? A) assuming the new tax level will be permanent. B) saving most of the additional disposable income. C) increasing consumption sharply in response to the higher disposable ...

*October 3, 2013*

**Contempoary Mthematics**

the amount of money

*October 3, 2013*

**Algebra 2**

| t - 7 | + 3 > or = 4

*September 24, 2013*

**Calculus**

nevermind it won't accept ANY answer now so it doesn't matter

*September 24, 2013*