Wednesday

September 28, 2016
Total # Posts: 208

**Chemistry**

DR.BOB222 ENGLISH PLEASE?????? I know how to get the beta decay for strontium. just having a hard time with the concentration of strontium and the amount of yrs. passed....please help!!

*November 11, 2011*

**Chemistry**

The half-life for beta decay of strontium-90 is 28.8 years. A milk sample is found to contain 10.3 ppm strontium-90. How many years would pass before the strontium-90 concentration would drop to 1.0 ppm?

*November 11, 2011*

**Chemistry**

so what is the molar mass? i know that v= ? * .805/263K, but im stuck on this one???

*November 11, 2011*

**Chemistry**

There is a balloon filled with methane,CH4. If the mass of the methane is 68.34g, what is the volume of the balloon at 0.805 atm and a temperature of -10*C?

*November 11, 2011*

**Chemistry**

yes 211 L? is that right?

*November 11, 2011*

**Chemistry**

211

*November 11, 2011*

**Chemistry**

a cylinder of helium has a volume of 8.0 L. The pressure of the gas is 388 lb in -2 at 25*C. What volume will the helium occupy at a standard atmospheric pressure (14.7 lb in -2) assuming there is no temperature change?

*November 11, 2011*

**Chemistry**

k thanks so much for your help!

*November 11, 2011*

**Chemistry**

so is it 2.9 E26??

*November 11, 2011*

**Chemistry**

a diver exhales a bubble with a volume of 250mL at a pressure of 2.4atm and a temp. of 15*C. How many gas particles are in this bubble?

*November 11, 2011*

**Geometry**

Yay!!!! Thank you very much ms Sue! I appreciate the help:)

*November 8, 2011*

**Geometry**

Find the area of the trapezoid. L1 = 23ft, L2 = 15ft, H = 12ft Is 228 ft the correct answer?

*November 8, 2011*

**Geometry**

Find the missing side. Approximate the answer to three decimal places when appropriate. A = 15 yd C = 25 yd I have no clue on how to do this one. Please any help would be appreciated.

*November 8, 2011*

**Geometry**

Find the area of the trapezoid. L1 = 23ft, L2 = 15ft, H = 12ft Is 456ft the correct answer?

*November 8, 2011*

**Geometry**

Find the area of the parallelogram. L1= 19m, L2 = 25m Can you explains this? Do I multiply? Is the answer 475m?

*November 8, 2011*

**Geometry **

Yay! Thanks so much!

*November 8, 2011*

**Geometry **

Find the area of the square. L = 14 yd Can you explain this? Is the answer 14x14=196? Thank you kindly

*November 8, 2011*

**Geometry**

Great! So the answer is 39! :D

*November 8, 2011*

**Geometry**

Find the area of the rectangle. L = 13m and H = 3m Do I multiply or do I add?

*November 8, 2011*

**Geometry**

Find the perimeter of the trapezoid. L1 = 9.65 yd, L2 = 9.25 yd, L3 = 10.12 yd, and L4 = 6.20 yd Can you please explain how I answer this? Thank you kindly:)

*November 8, 2011*

**Geometry **

Find the perimeter of the regular hexagon. L = 4.55 yd Do I multiply by 6 because it has six sides? Is the answer 27.30?

*November 8, 2011*

**Math **

in a 30degree-60degree right triangle, the length of the side opposite the 60 degree angle is 8.3m. How long is the hypotenuse?.

*November 7, 2011*

**Geometry **

Yay!!!

*November 7, 2011*

**Geometry **

Find the circumference of the circle (use 3.14) D=5.95yd Is the answer 18.683 yd?

*November 7, 2011*

**Geometry **

Yay!!!! Thanks so much!!!!

*November 7, 2011*

**Geometry **

To find the perimeter of the triangle do I add all the sides together? L1 = 12.5in, L2 = 10.6 in, and L3 = 9.5 in Is the answer 32.6?

*November 7, 2011*

**Geometry for Ms Sue?**

Referring to my last question.. Does 26.64 yd mean 26 2/3?

*November 7, 2011*

**Geometry **

Does that mean the same thing as 26 2/3?

*November 7, 2011*

**Geometry **

If I add four of those sides together I get 26.64?

*November 7, 2011*

**Geometry **

find the perimeter of the square. L = 6.66 yd Is the answer 26 yd?

*November 7, 2011*

**Geometry **

ah i see 33.4in

*November 7, 2011*

**Geometry **

Is the answer 16.7in?

*November 7, 2011*

**Geometry **

How do you find the perimeter of the rectangle? L = 10.6 in and h = 6.1 in Can someone please explain this to me? Thank you kindly.

*November 7, 2011*

**government**

Using the Internet, encyclopedia, and/other reference material for research, write a 1,000-word report on feudalism in the history in one of the following countries: •France •England •Germany Include the approximate years when feudalism began and ended in that ...

*November 5, 2011*

**government**

thank you very helpful

*November 5, 2011*

**government**

Using any resources you choose, write several paragraphs stating advantages and disadvantages to the unitary, confederate, and federal systems of government.

*November 5, 2011*

**Algebra-Graphing**

I need to find the vertex, axis of symmetry, and if the graph will open upward or downword f(x)=-3x^2-5

*November 2, 2011*

**Food styles of catering**

which of the following gadgets is best for making a soft-shell shape out of butter?

*November 1, 2011*

**math**

Oh great! Thanks!

*November 1, 2011*

**math**

How do I solve it?

*November 1, 2011*

**math**

Johns football game last for 50 minutes. What reduced fraction of an hour is that? Can someone please explain to me how to solve this question?

*November 1, 2011*

**Math**

I got the answer 1 by doing this... 15 divided by 3 = 5 5 divided by 5 = 1 Is that a wrong way to answer the problem? That's the way my book shows.

*November 1, 2011*

**Algebra**

i^20

*October 24, 2011*

**Algebra**

Use the square root property to solve for the indicated variable. Assume that the variable represents positive numbers. Express all radicals in simplied form. 2e^2 = 3h, for e

*October 23, 2011*

**chemistry**

Phosphorus trichloride gas and chlorine gas reacts to form phosphorus pentachloride gas: PCL3(g) +CL2(g) = PCL5(g). A vessel is CHARGED WITH A MIXTURE OF PCL3(g) and CL2(g), which is allowed to equilibrate at 450K. At equlibrium the partial pressures of the three gases are ...

*October 19, 2011*

**Chemistry**

a 1.00-mol sample of phosphorus pentachloride placed in 10.0-L reaction flask and allowed to come to equilibrium at 250 degrees celsius; PCL5(g) = PCL3(g) Cl2(g) if the amount of chlorine in the equilibrium mixture is0.470 mol, calculate (a) the equilibrium concentration of ...

*October 19, 2011*

**calculus**

my circular swimming pool has a 29 foot diameter and is 8 feet tall. at the beginning of the summer i need to fill the pool with water. the flow rate from my spigot into the pool is about 0.75 cubic feet per minute. how fast is the water level, h, rising at the moment when the...

*October 16, 2011*

**calculus**

an airplane is flying at an altitude of 6.7 miles towards a point directly over an observer. if the speed of the plane is 499 miles per hour, find the rate at which the angle of observation, Ɵ, changing by at the moment when the angle is 21 degrees.

*October 16, 2011*

**calculus**

y(x)=c^x+x^c =y'(x)=x*c+2x =y'(x)=cx+2x

*October 16, 2011*

**Algebra**

thank you

*June 12, 2011*

**Algebra**

opps, sorry its: (n+5)/(n+8)=1+6(n+1)

*June 12, 2011*

**Algebra**

(n+5)/(n+8)=1=6/(n+1)

*June 12, 2011*

**algebra**

thank you sooo much :)

*June 12, 2011*

**algebra**

5/(n^3=5n^2)=4/(n+5)+1/n^2

*June 12, 2011*

**algebra**

If y is inversely proportional to x, and y=8 when x=2, find y when x=5

*June 10, 2011*

**algebra**

thank you

*May 29, 2011*

**algebra**

sorry it posted stupid, its: 3/x + 4/x+2 = -1/x

*May 29, 2011*

**algebra**

3 4 1 - + --- = - - x x+2 x

*May 29, 2011*

**algebra**

im not sure how to solve this: x^2 --- -9 x^2-9

*May 29, 2011*

**algebra**

a merchant wants to stock the shelves with 100 Ibs. of a mixed nuts that cost $8.00 a Ibs. the merchant has cashews and peanuts. peanuts cost $6.00 a Ibs. and cashews cost $12.00 a Ibs. how many Ibs. of each should the merchant use in the mixture?

*April 27, 2011*

**math**

thank you guys so much

*April 27, 2011*

**math**

A boat traveled 45 miles downstream (w/ the current) in 3 hours and made the return trop (against the current) in 5 hours. What was the speed of the boat and what was the speed of the current?

*April 27, 2011*

**math**

how do you rewrite the expression to the 1st power of cosine by using power-reducing formulas? PLEASE AND THANK YOU :D sin^2xcos^4x

*March 21, 2011*

**psychology- the mind at work **

11. By comparison with the Stanford-Binet IQ measure, an advantage of the Wechsler Scales is that they A. have never been associated with the concept of mental age. B. accentuate the importance of reasoning over performance. C. provide an advantage to people who don’t ...

*January 31, 2011*

**Geometry**

In rhombus ABCD, AB=20 and AC=25. Find the area of the rhombus to the nearest tenth.

*January 7, 2011*

**Psychology ; the mind at work**

those answere are not right so dont use them

*October 21, 2010*

**algebra**

oh ok :)

*October 4, 2010*

**algebra**

my way worked too

*October 4, 2010*

**algebra**

15ft imagine a triangle. The diagonal side is 17 ft. the bottom is 8 ft. Use the pythagorean theorem to find the third side. so 17^2 minus 8^2 = 225. then take the square root of 225, which is 15

*October 4, 2010*

**math**

x-5 where x is any number and then you can plug any number is for x and subtract 5

*October 4, 2010*

**Pre-Calculus**

The side of a rhombus is 15 centimeters long, and the length of its longer diagonal is 24.6 centimeters. Find the area.

*October 4, 2010*

**Algebra story problem**

a) within implies + or - 3, so I believe 48-3 or 48+3,would be 45-51% range, but they want the minimum, so 45% is final answer

*September 29, 2010*

**Physics I**

educated guess= 5 constant speed(no swinging) make constant angle(circle)

*September 29, 2010*

**algebra**

An airplane flies 750 miles due west in 1 1/2 hours and 750 miles due south in 2 hours. What is the average speed of the airplane?

*September 2, 2010*

**algebra**

Mr. Anders and Ms. Rich each drove home from a business meeting. Mr. Anders traveled east at 100 Kilometers per and hour and Ms. Rich traveled west at 80 kilometers per hour. In how many hours were they 100 kilometers apart?

*September 2, 2010*

**Chemistry**

What the heck is that suppose to mean? There's no need to be condescending.

*March 11, 2010*

**chemistry**

Well we basically took antacid tablets dissolved them in HCl, heated it and then added phenolthalien and then titrated until we saw a pink color. At 41mL we saw the pink and stopped. So I guess like you said, I think I have to figure out the excess HCl present but how do I do ...

*March 11, 2010*

**chemistry**

Question about titration calculations in analysis of antacids lab. We did a lab yesterday with antacids, HCl and NaOH and I'm having trouble doing the calculations. The information known is the following: 1)0.10M NaOH 2)0.10M HCl 3)Mass of Antacid .22g 4)Volume of NaOH ...

*March 11, 2010*

**Chemistry**

Pure acetic acid, known as glacial acetic acid, is a liquid with a density of 1.049 g/mL at 25°C. Calculate the molarity of a solution of acetic acid made by dissolving 10.00 mL of glacial acetic acid at 25°C in enough water to make 150.0 mL of solution.

*February 17, 2010*

**Chemistry**

Sally Scientist is trying to determine Avogadro's number using a procedure analogous to that in Experiment 4. She fills a watchglass with diameter 11.9 cm with water and is trying to create a monolayer of stearic acid on the top of the water. What is the area of the water ...

*February 7, 2010*

**Math**

The strength of a cable is proportional to the square of its diameter. If a 2-cm cable will support 800kg, how much will a 3-cm cable support?

*January 10, 2010*

**Math**

Ellie and Tanya each have bank accounts.Ellie has $500 and Tanya has $200.Ellie withdraws $15 each weekend while Tanya deposits $12.At the end of 13 weeks what is the difference in their bank accounts?Solve this algebraically.Can you find a week when there is only a $3 ...

*January 7, 2010*

**Math**

The Tao Inc. purchased an asset for $170,000 with a salvage value of $8,500 have a useful life of four years. Find the depreciation expense for the first year using the 150% declining balance method.

*November 10, 2009*

**Physics**

Or save yourself the trouble and use the following formula. I just did this problem. (m1*v01)/(m1+m2)

*October 28, 2009*

**Literature / Short story I**

yeah those are right thinks i got 100

*March 13, 2009*

**Math**

Julia studied math for 3 1/2 hours during the 4 days before her last math test. What was the average amount of time she studied each day?

*December 11, 2008*

**Math**

Ms.Daza bought 3 1/2 yards of fabric. She used 2/3 of the fabric to make a costume. How much fabric did she use?

*December 11, 2008*

**unscrambling word**

I NEED HELP UNSCRAMBALING "NOKMEERITLEE" IT MIGHT BE MORE THEN ONE WORD

*October 8, 2008*

**literature novels**

-------------------------------------------------------------------------------- -------------------------------------------------------------------------------- -------------------------------------------------------------------------------- -------------------------------------------------------------------------------- 1. B Correct 2. C Correct 3. C Correct 4. D Correct 5. D Correct 6. C Correct 7. B Correct 8. B Correct 9. A Correct 10. B Correct 11. A Correct 12. D Correct 13. A Correct 14. B Correct 15. D Correct 16. C Correct 17. A Correct 18. C Correct 19. A Correct 20. D Correct

*July 1, 2008*

**literature**

1. C Correct 2. B Correct 3. D C STUDY GUID 98-100 4. A Correct 5. C Correct 6. C Correct 7. D Correct 8. B C STUDY GUID 90-95 9. C Correct 10. D Correct 11. A Correct 12. B Correct 13. D Correct 14. D Correct 15. B Correct 16. A Correct 17. B Correct 18. A Correct 19. B ...

*June 7, 2008*

**algebra**

i need help with my math problem: x varies directly as the square of s and inversely as t. how does x change when s is doubled? when both x and t are doubled?

*May 26, 2008*

**Social Studies**

Many of the Romans thought that, and that was their belief. So I hope that helps

*May 19, 2008*

**Spanish**

I dont understand the instructions. I want to help you though.

*May 9, 2008*

**Spanish**

2. Devuelvan 11. Vengan 12. Use 15. Recuerden

*May 9, 2008*

**simplyfying expressions (trig)**

can anyone tell me how to do this? thanks! (sin (x) / 1 + cos (x) ) + ( cot (x) / 1 + cos (x) )

*May 9, 2008*

**trig**

Find a polar equation of this conic with focus at the pole and the given eccentricity and directrix. e=2, r cos X =-1

*April 29, 2008*

**trig**

what is the rectangular equation for r=12/(3-6cosX).

*April 29, 2008*

**social studies**

what was the substance used to stuff the nostrils of the mummy's in egypt

*March 28, 2008*

**math**

i love math naw thank you for the help

*December 12, 2007*

**Math**

i just love math

*December 7, 2007*