Tuesday

May 31, 2016
Total # Posts: 780

**Physics**

An equivalent definition can be based on the fact that an exposure of one roentgen deposits 8.30 x 10-3 J of energy per kilogram of dry air. Using the two definitions and assuming that all ions produced are singly charged, determine the average energy (in eV) needed to produce...
*August 4, 2012*

**Physics**

A neutron causes the element 88X232 to change according to the reaction 0n1 + 88X232 ---->ZYA + . Identify the (a) atomic number and (b) atomic mass number of the daughter nucleus. (c) This product subsequently undergoes - decay, and its daughter does too. Identify the ...
*August 3, 2012*

**Physics**

One kilogram of dry air at STP conditions is exposed to 1.00 R of X-rays. One roentgen is defined by Equation 32.1 in Section 32.1. An equivalent definition can be based on the fact that an exposure of one roentgen deposits 8.30 x 10-3 J of energy per kilogram of dry air. ...
*August 3, 2012*

**Physics**

Suppose a nucleus of 93X236 fissions into two fragments whose mass ratio is 0.37:0.63. With the aid of the drawing, estimate the energy (in MeV) released during this fission. The drawing Shows A large. The A1 smaller the A2, A2 is nearly double the size of A1
*August 3, 2012*

**Physics**

Consider the induced nuclear reaction 1H2 + 7N14 ---->6C12 + 2He4. The atomic masses are 1H2 (2.014102 u), 7N14 (14.003074 u), 6C12 (12.000000 u), 2He4 (4.0026030 u). Determine the energy (in MeV) released when the 6C12 and 2He4 nuclei are formed in this manner.
*August 1, 2012*

**Physics**

Suppose a nucleus of 93X236 fissions into two fragments whose mass ratio is 0.37:0.63. With the aid of the drawing, estimate the energy (in MeV) released during this fission. Ive treied to do this problem but i keep getting the wrong answer. I keep getting 164.253 MeV
*August 1, 2012*

**math**

Please simplify (-3)2(-3)2 + 22 * (5)(-1)
*July 30, 2012*

**Chemisty**

For an electron in a hydrogen atom, the z component of the angular momentum has a maximum value of Lz = 4.22 x 10-34 J·s. Find the smallest possible value (algebraically) for the total energy (in electron volts) that this atom could have
*July 29, 2012*

**Physics**

Determine the activity of 1.11 g of 88Ra226 (a) in disintegrations per second (Bq) (b) and in Curies (Ci). The half-life is 1600 yr (1 yr = 3.156 x 10^7 s). 1 Ci is equal to 3.7 x 10^10 Bq. I keep getting the wrong answer and use the equation H=kNo
*July 29, 2012*

**Physics**

When any radioactive dating method is used, experimental error in the measurement of the sample's activity leads to error in the estimated age. In an application of the radiocarbon dating technique to certain fossils, an activity of 0.15 Bq per gram of carbon is measured ...
*July 27, 2012*

**chemistry**

Determine the activity of 1.11 g of 88Ra226 (a) in disintegrations per second (Bq) (b) and in Curies (Ci). The half-life is 1600 yr (1 yr = 3.156 x 10^7 s). 1 Ci is equal to 3.7 x 10^10 Bq.
*July 27, 2012*

**Physics**

How many half-lives are required for the number of radioactive nuclei to decrease to 1/10^4 of the initial number?
*July 27, 2012*

**Physics**

When uranium 92U235 decays, it emits a ray. If the emitted ray has a wavelength of 1.30 x 10-11 m, determine the energy (in MeV) of the ray
*July 27, 2012*

**physics**

Thanks It deffinatly helped some. I also realised I was downsizing the number to much.
*July 21, 2012*

**physics**

Find the wavelength (in nm) of a photon whose energy is 5.90 x 10-19 J. I understand that I have to use this equation to figure out the problem E=nhf, I just keep getting the wrong answer. Which is 33.68 nm
*July 21, 2012*

**Physics**

As Section 27.5 discusses, sound waves diffract or bend around the edges of a doorway. Larger wavelengths diffract more than smaller wavelengths. (a) The speed of sound is 343 m/s. With what speed would a 57.0 kg person have to move through a doorway to diffract to the same ...
*July 21, 2012*

**Physics**

Interesting. Im glad I wasn't to far off on the answer. Makes me feel a little better about everything. Thank you so much!!!
*July 21, 2012*

**Physics**

Two spaceships A and B are exploring a new planet. Relative to this planet, spaceship A has a speed of 0.54c, and spaceship B has a speed of 0.74c. What is the ratio DA/DB of the values for the planet's diameter that each spaceship measures in a direction that is parallel ...
*July 21, 2012*

**Physics**

A woman is 1.6 m tall and has a mass of 53 kg. She moves past an observer with the direction of the motion parallel to her height. The observer measures her relativistic momentum to have a magnitude of 2.6 x 1011 kg·m/s. What does the observer measure for her height?
*July 21, 2012*

**Physics**

Thank you. i sort of had to back track to get the answer you got but eventually got it. Thank you!!
*July 20, 2012*

**Physics**

A spacecraft approaching the earth launches an exploration vehicle. After the launch, an observer on earth sees the spacecraft approaching at a speed of 0.74c and the exploration vehicle approaching at a speed of 0.98c. What is the speed of the exploration vehicle relative to ...
*July 20, 2012*

**Physics**

Determine the ratio of the relativistic kinetic energy to the nonrelativistic kinetic energy (1/2mv2) when a particle has a speed of (a) 2.12 x 10-3c. and (b) 0.959c.
*July 20, 2012*

**Physics**

suppose that the angle of incidence is 1 = 37.1°, the thickness of the pane is 4.17 mm, and the refractive index of the pane is n2 = 1.50. Find the amount (in mm) by which the emergent ray is displaced relative to the incident ray.
*July 14, 2012*

**Physics**

Light waves with two different wavelengths, 632 nm and 474 nm, pass simultaneously through a single slit whose width is 4.47 x 10-5 m and strike a screen 1.70 m from the slit. Two diffraction patterns are formed on the screen. What is the distance (in cm) between the common ...
*July 14, 2012*

**Physics**

A compound microscope has a barrel whose length is 17.4 cm and an eyepiece whose focal length is 1.7 cm. The viewer has a near point located 25 cm from his eyes. What focal length must the objective have so the angular magnification of the microscope is -330?
*July 14, 2012*

**Physics**

So 34.2/14.6?
*July 14, 2012*

**Physics**

A converging lens (f = 14.6 cm) is located 39.0 cm to the left of a diverging lens (f = -4.57 cm). A postage stamp is placed 34.2 cm to the left of the converging lens. (a) Locate the final image of the stamp relative to the diverging lens. (b) Find the overall magnification.
*July 14, 2012*

**Physics**

An office copier uses a lens to place an image of a document onto a rotating drum. The copy is made from this image. (a) What kind of lens is used? Should it be 1 - converging, or 2 - diverging? Suppose the lens has a focal length of magnitude 13.0 cm. If the document and its ...
*July 14, 2012*

**math 091**

s+(-s)+1/9(9)
*June 25, 2012*

**Physics**

Identical +3.92 ìC charges are fixed to adjacent corners of a square. What charge (magnitude and algebraic sign) should be fixed to one of the empty corners, so that the total potential at the remaining empty corner is 0 V?
*June 16, 2012*

**Physics**

Two wires have the same length and the same resistance but are made up of different materials. The resistivities of these materials are 3.97 Ù and 1.97 Ù. Obtain the ratio of the smaller cross-sectional area to the greater cross-sectional area.
*June 13, 2012*

**Physics**

Consider three conducting spheres each 10 cm in diameter. “A” has a net charge of 5 C, “B” has a net charge of 10 C, and “C” has a net charge of zero, but is placed in an electric field of 1000 V/m. Rank the electric field strength inside the ...
*June 13, 2012*

**Physics**

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 0.24 m from the spot, while charge B is 0.37 m from it. Find the ratio qB/qA of the charges.
*June 13, 2012*

**Sceince**

The drawing shows an edge-on view of two planar surfaces thatintersect and are mutually perpendicular. Surface 1 has an area of 1.7 m^2, while surface 2 san area of 3.2 m^2. The electric field in the drawing is uniform andhas a magnitude of 250 N/C. Find the electrical flux ...
*June 10, 2012*

**Physics 1**

Three charges are fixed to an xy coordinate system. A charge of +16C is on the y axis at y = +3.1 m. A charge of -16C is at the origin. Lastly, a charge of +55C is on the x axis at x = +3.1 m. Determine (a) the magnitude and (b) direction of the net electrostatic force on the ...
*June 9, 2012*

**Physics**

The drawing shows an edge-on view of two planar surfaces thatintersect and are mutually perpendicular. Surface 1 has an area of 1.7 m^2, while surface 2 san area of 3.2 m^2. The electric field in the drawing is uniform andhas a magnitude of 250 N/C. Find the electrical flux ...
*June 9, 2012*

**algebra**

if a stock price starts at $61 goes up $3, goes up $2, goes down $1, down $4, goes down $5 what is the stock worth
*June 1, 2012*

**Science-Physics**

One of the things that helped our understanding of radioactivity was the discovery of the electron in 1897. The 100th anniversary of this important discovery was celebrated widely in 1997. Explain why more people were aware of the 100th anniversary than of the original discovery.
*May 28, 2012*

**Geography**

how many states are surrounded by water?
*May 15, 2012*

**Physics 121**

The disk has mass 10kg and radius 0.25m. The rod has mass 5kg, length 0.5m and radius 0.05m. The rod is split down the middle and is hinged so that its two halves can lay flat against the disk. Suppose that the disk and rod are initially rotating at 3.0rad/s around the axis ...
*May 6, 2012*

**Statistics**

When fifteen vehicles were observed at random for their speeds (in M.P.H.) on a freeway, the following data were obtained. 61 53 57 55 62 58 60 54 62 60 59 66 55 54 63 Suppose that from past experience it may be assumed that vehicle speed is normally distributed with standard ...
*April 30, 2012*

**Chemistry**

Thank you so much for your help! I was able to follow your steps very well! Much appreciated DrBob222!
*April 29, 2012*

**Chemistry**

For the strong acids find the [H3O]and [OH] in a solution that is .785% HNO3 by mass (assume a density of 1.01 g/ml). If someone could offer step by step instructions, that would be terrific!
*April 29, 2012*

**Chemistry**

A solution contains an unknown mass of dissolved barium ions. When sodium sulfate is added to the solution, a white precipitate forms. The precipitate is filtered and dried and found to have a mass of 258 mg. What mass of baium was in the original solution? (Assume that all of...
*April 12, 2012*

**Chemistry **

Describe how you would prepare 2.00 L of an aqueous solution having a pH=3.60, if you had a supply of 0.100 M HCl available.
*April 12, 2012*

**Math**

A Sears Relvolving charge card has a monthly rate of 1.75%, the interest is a minimum of $.50 if the average daily balance is $28.50 less. Explain how this poilicy is beneficial to Sears.
*April 4, 2012*

**Physics**

Two disks are rotating about the same axis. Disk A has a moment of inertia of 4.53 kg·m2 and an angular velocity of +4.55 rad/s. Disk B is rotating with an angular velocity of -6.86 rad/s. The two disks are then linked together without the aid of any external torques, ...
*April 1, 2012*

**Physics**

The drawing shows two identical systems of objects; each consists of the same three small balls connected by massless rods. In both systems the axis is perpendicular to the page, but it is located at a different place, as shown. The same force of magnitude F is applied to the ...
*April 1, 2012*

**English **

Is this a correct sentence Be careful whom you tell.
*March 27, 2012*

**accounting**

Part 5 Cash Budgeting Landis Company has the following sales forecasts for the selected three-month period in the current year: Month Sales April $12,000 May 7,000 June 8,000 Seventy percent of sales are collected in the month of the sale, and the remaining balance is ...
*March 25, 2012*

**Science/Chemistry**

Molarity = mol/ L = 0.0025 / 0.00368 L = .679 M
*March 21, 2012*

**algebra**

The period of a pendulum is the time it takes to swing from left to right and back again. The period T seconds, of a pendulum is directly proportional to the square root of its length, Lcm. When L=25, T=1 Find a formula for T in terms of L.
*March 20, 2012*

**Math**

Evaluate the expression below log 243 9
*March 19, 2012*

**english 11**

it said the answers are D D B A D B
*March 14, 2012*

**English 11**

Yeahp rosco
*March 12, 2012*

**algebra**

Which is the eighth term in the sequence an=-1/125(5^n-1)
*March 10, 2012*

**math**

Which is the eighth term in the sequence an=-1/125(5^n-1)
*March 10, 2012*

**Literature **

The best in this kind are but shadows" is A. Titania talking about men. B. Theseus talking about plays. C. Demetrius talking about the women he has loved in the past. D. Bottom talking about his fellow craftsmen.
*March 8, 2012*

**Chem 2**

The following system is at equilibrium with [N2O4] = 0.55 M and [NO2] = 0.25 M. If an additional 0.10 M NO2 is added to the reaction mixture with no change in volume, what will be the new equilibrium concentration of N2O4? N2O4(g) 2 NO2(g)
*March 5, 2012*

**Math**

Can you help simplify this expression. (x+x/3) divided by (x-x/6)
*February 28, 2012*

**math**

Can you help simplify this expression. (x+x/3) divided by (x-x/6)
*February 28, 2012*

**Algebra **

Can you help simplify this expression. (x+x/3) divided by (x-x/6)
*February 28, 2012*

**trig**

in this right trianlge ABC, m<c=90, m<a=63, and AB=10. if BC is represented by a, then which equation can be used to find a?
*February 28, 2012*

**trig**

solve for x log4 64+ log2 2 ________________ =x log3 81
*February 28, 2012*

**stats**

Web Results For: the value of the z-score in a hypothesis test is influenced by a vareity of factors. Assuming other variables are held constant, explain how the value of z is influenced by increasing the difference between teh sample mean and the original population mean
*February 28, 2012*

**ACC291**

The following stockholders' equity accounts arranged alphabetically are in the ledger of McGrath Corporation at December 31, 2011. Common Stock ($10 stated value) $1,500,000 Paid-in Capital from Treasury Stock 6,000 Paid-in Capital in Excess of Stated Value-Common Stock ...
*February 27, 2012*

**medical front office**

How does bookkeeping and banking affect the position of the Medical Assistant?
*February 25, 2012*

**Axia College **

Need help with solving the double equation problem. 3x + 2y = 3 9x - 8y = -2
*February 23, 2012*

**statistics**

Suppose IQ scores have a bell-shaped distribution with a mean of 100 and a standard deviation of 15. What percentage of the scores are above 130?
*February 23, 2012*

**Physics**

How much work is done by a girl weighing 450N while carrying a 2kg package up a 2m flight of stairs?
*February 16, 2012*

**Math**

If A, B, and C stand for different digits, and BA+AC=BCA, what digits do A, B, and C represent? Please Help!
*February 13, 2012*

**Math**

If A, B, and C stand for different digits, and BA+AC=BCA, what digits do A, B, and C represent? Please Help!
*February 13, 2012*

**Algebra **

Write an equation for the ellipse that satisfies the set of conditions. endpoint of major axis at ( 0, 10) and (0, -10) foci at (0, 8) and (0-8) Please help, I really don't understand how to do this
*February 12, 2012*

**accounting**

P4-2A The adjusted trial balance columns of the worksheet for Porter Company are as follows. PORTER COMPANY Worksheet For the Year Ended December 31, 2008 Adjusted Account Trial Balance No. Account Titles Dr. Cr. 101 Cash 18,800 112 Accounts Receivable 16,200 126 Supplies 2,...
*February 9, 2012*

**accounting**

Worksheet data for Goode Company are presented in E4-2. Instructions (a) Journalize the closing entries at April 30. (b) Post the closing entries to Income Summary and Retained Earnings. Use T accounts. (c) Prepare a post-closing trial balance at April 30. Cash 13,752 ...
*February 9, 2012*

**Accounting**

Worksheet data for Goode Company are presented in E4-2. Instructions (a) Journalize the closing entries at April 30. (b) Post the closing entries to Income Summary and Retained Earnings. Use T accounts. (c) Prepare a post-closing trial balance at April 30. Cash 13,752 Accounts...
*February 8, 2012*

**chemistry**

using the conversion of mass if the reactant has 4 atoms of calcium how many atoms of calcium will the product have?
*February 5, 2012*

**physics**

A rock dropped from an airplane falls for 13.6 seconds before hitting the ground. How far above the ground was the airplane when the rock was dropped?
*February 5, 2012*

**Social Studies**

I need a picture of Charles B. Brooks the inventor of the street sweeper. I can't find one anywhere; could you help me. I'm doing a project and need a picture of him.
*February 2, 2012*

**Physics**

An (63Kg) astronaut, floating alone in outer space, catches a 7Kg bowling ball traveling at 20m/s. The velocity of the astronaut and bowling ball after the catch is
*February 1, 2012*

**math**

A cricket produces 116 chirps per minute at 72 degrees Fahrenheit and 177 chirps per minute at 80 degrees Fahrenheit. Find a linear equation that models the temperature as a function of the number of chirps per minute .
*February 1, 2012*

**math**

mrsdryson is divding her collection of 52 glass bears into equal groups. she has 1 bear left over. how many did mrs.dryson make
*January 19, 2012*

**statistics**

what is the value of P(6,4)?
*January 17, 2012*

**algebra**

Find the future value of an ordinary annuity. Payments are made and interest is compounded as follows: R=600 7% interest compounded quarterly for 5 years I set this up as follows and still am getting the wrong answer: 500 (1.07)^5-1/0.07 Please help!!
*December 15, 2011*

**Psycholofgy**

d. conformity, compliance
*December 12, 2011*

**algebra**

find the size of each 5 payments made at the end of each year into a 6% rate sinking fund which produces 76000 at the end of 5 years
*December 7, 2011*

**physics**

Rhonda Vous, the 445N human cannonball, is shot from her cannon, leaving it at 18.0 m/s. How much work did the cannon do on her?
*December 7, 2011*

**Calculus**

A cylindrical water tank has a radius of 2 feet and a height of 6.0 feet. Compute the work done to pump the water out of a filled tank through the top. [The density of water is 62.4 lbs/ft3.]
*December 6, 2011*

**calculus**

Find the volume of the solid formed by revolving the region bounded by y=1-x, y=x-4, x=0 about x=7
*December 6, 2011*

**calculus**

The pdf describing the chance that a given insect will die at a particular age, x days, is f(x)=4.1x10^-2 xe^-.2x. What is the chance the insect will live between 2 and 4 days?
*December 6, 2011*

**calculus**

The base of a solid V is the region bounded by y=(x^2/64) and y=sq(x/8) Find the volume if V has square cross sections
*December 6, 2011*

**math**

4.Suppose John sells his house and earns a profit of $600,000. With the profit, he buys a 20 year annuity that earns 6.5% interest compounded monthly. What monthly payment will John get?
*December 5, 2011*

**Math**

3 ç (x - 2)11 dx = 1
*December 4, 2011*

**Math**

Find the arc length of y = x^4 from the origin to (1, 1). Answer in length units, correct to two decimal places, please.
*December 4, 2011*

**Math**

Revolve the region bounded by y = 4x and y = x^2 about the y-axis. In cubic units, the resulting volume is
*December 4, 2011*

**Calculus**

Compute the volume of the solid formed by revolving the fourth quadrant region bounded by y = x^2 - 1 , y = 0, and x = 0 about the line y = 9.
*December 4, 2011*

**Calculus**

Find the total area bounded by the curves y = x^3 and y = x^5 .
*December 4, 2011*

**Calculus**

Compute the volume of the solid formed by revolving the fourth quadrant region bounded by y = x^2 - 1 , y = 0, and x = 0 about the line y = 6.
*December 3, 2011*

**Pre Calc**

Find the volume of the solid formed by revolving the region bounded by y = 16 - x^2 and y = 0 about the x-axis .
*December 3, 2011*

**Calculus**

Find the volume, in cubic units, generated by revolving the region bounded by y = x3 , x = 0, and y = 8, around the line x = 7 .
*December 2, 2011*