# Posts by joel

Total # Posts: 310

**Statistics**

Of 100 people who were given a vaccine,80 developed immunity to a disease.the 98% interval on the proportion of people developing immunity is?need help

*March 23, 2011*

**Chemistry**

What is a photon? Several selections may be correct. Has an energy of equal to hν. Is a unit of electromagnetic radiation. Is a part of the electromagnetic spectrum. Is usually called visible light. None of these.

*March 14, 2011*

**Chemistry**

a 23ml H2SO4 solution is titrated by 50 ml 0.10 M NaOH solution, what is the molarity of H2SO4 solution? (Note that H2SO4 is a diprotic acid)

*March 14, 2011*

**Algebra**

292

*March 8, 2011*

**Maths literacy**

Write 78/115 as a decimal fraction

*February 26, 2011*

**algebra**

Solve using the elimination method. Show your work. If the system has no solution or an infinite number of solutions, state this. -7x – 5y = 1.5 -5x – 4y = 4.5

*February 22, 2011*

**algebra**

Solve using the elimination method. Show your work. If the system has no solution or an infinite number of solutions, state this. -x – 8y = 43 4x + 32y = 172

*February 22, 2011*

**algebra**

A dehydrated patient needs a 3.82% saline IV. Unfortunately, the hospital only has bags of 4% and 3% saline solutions. How many liters of each of these solutions should be mixed together to yield 5 liters of the desired concentration?

*February 22, 2011*

**algebra**

To buy both a new car and a new house, Tina sought two loans totalling $319,531. The simple interest rate on the first loan was 2.7%, while the simple interest rate on the second loan was 2.6%. At the end of the first year, Tina paid a combined interest payment of $8334.15. ...

*February 22, 2011*

**algebra**

Select the set of equations that represents the following situation: Mary invested one amount at 7% simple interest, and a second amount at 5% interest, earning $29.80 in one year. If she had switched the amounts, she would have earned $35.00. What were the two amounts? (...

*February 22, 2011*

**algebra**

Select the set of equations that represents the following situation: Mary invested one amount at 7% simple interest, and a second amount at 5% interest, earning $29.80 in one year. If she had switched the amounts, she would have earned $35.00. What were the two amounts? (...

*February 22, 2011*

**algebra**

Select the set of equations that represents the following situation: The cost of eleven CDs and twelve DVDs is $150.62; and the cost of one DVDs and twelve CDs is $116.07. How much do a CD and a DVD cost? (Points : 3) 11x + 12y = 150.62; 12x + 1y = 116.07 11x • 12y = 150....

*February 22, 2011*

**algebra**

Solve using the elimination method. Show your work. If the system has no solution or an infinite number of solutions, state this. -3x + 4y = -19.5 -3x + y = -10.5

*February 22, 2011*

**algebra**

Solve using the substitution method. Show your work. If the system has no solution or an infinite number of solutions, state this. x + 10y = 41 x + 9y = 37

*February 22, 2011*

**algebra**

Select the set of equations that represents the following situation: Mary invested one amount at 7% simple interest, and a second amount at 5% interest, earning $29.80 in one year. If she had switched the amounts, she would have earned $35.00. What were the two amounts?

*February 22, 2011*

**Algebra**

Cody’s motorboat took 3 hr to make a trip downstream with a 6-mph current. The return trip against the same current took 5 hr. Find the speed of the boat in still water

*February 22, 2011*

**intermediate algebra**

Select the set of equations that represents the following situation: Mike invested $706 for one year. He invested part of it at 5% and the rest at 3%. At the end of the year he earned $28.00 in interest. How much did Mike invest at each rate of interest?

*February 21, 2011*

**Physics**

A Force,F=10N,applied at an angle of 37 degree above the horizontal,moves a crate a distance of 5m along a rough horizontal surface.A frictional force of 5N opposes the motion.what is the change in kinetic energy?

*February 18, 2011*

**statistics**

the correlation between two random variables X and Y is p=-0.75.it is given that X=1,2or3 with equal probability of 1/3 and Y=-1,-2or-3 with equal probability of 1/3.the covariance is equal to?i need help.i have been struggling to get the answer>

*February 11, 2011*

**Physics**

A 3kg mass moving initially to the right along the x axis with a speed of 8m/s makes a perfectly inelastic collision with a 5kg mass initially at rest at the origin.what fraction of the initial kinetic energy of the system is lost in the collision.what formula must i use.

*February 2, 2011*

**Physics**

A 3kg mass moving initially to the right along the x axis with a speed of 8m/s makes a perfectly inelastic collision with a 5kg mass initially at rest at the origin.what fraction of the initial kinetic energy of the system is lost in the collision.what formula must i use.

*February 2, 2011*

**Pre-Algebra**

Thank you, Ms. Sue!

*January 24, 2011*

**Pre-Algebra**

If 4 liters of motor oil cost $3.88, what is the price for 1 liter? I'm supposed yo set up proportions. This is how I set it up: $3.88/4 liters • 1 liter/p p= the price for 1 liter Please tell me if I set it up right and how to solve.

*January 24, 2011*

**physical science**

gravity

*January 17, 2011*

**Maths**

is 10*10exponent -3 a scientific notation?

*January 17, 2011*

**Physics**

Two points charges of 2uC and -6uC are located at the position(0.0)m and (0.3)m.Calculate the total electrical potential at the point (4.0)m due these two charges.

*January 17, 2011*

**Physics**

hi Esskay,can u help me with the answer

*January 17, 2011*

**Physics**

A proton is released from rest in a uniform electric field which is directed along the x axis and of magnitude E=2*10exponent5 V/m.The proton undergoes a displacement from point A at the origin to point B at x=0.2m.What is the change in the potential energy of the proton ...

*January 17, 2011*

**Physics**

if a ball is thrown straight upward and is caught 5s after being thrown,how fast must it have been going when it left the person s hand?help

*January 17, 2011*

**physics**

if a ball is thrown vertically upward and is caught 5 seconds,how fast must have been going when it left the person s hand?help

*January 14, 2011*

**math**

Write a missing addend addition sentence to help solve 78-49.explain how you would use it.

*January 2, 2011*

**PHYSICS**

They both experience the same impact force however the fly will experience a greater acceleration

*November 30, 2010*

**Phys**

V = (f)* (wavelength) 200m/s = 100hz * Wavelength solve for wavelength then multiply by 3 dont forget to use the units for each variable like he gave us in class i.e. frequency = vibration/time wavelength = distance/vibration velocity = distance/time

*November 30, 2010*

**Physics**

I know for sure that the answer is not B or C since the volume increases and the temperature increases, however i am having a hard time understanding the definition of an adiabatic process and how to determine if there is any heat lost to the atmosphere. I am pretty sure the ...

*November 30, 2010*

**Physics**

A gas is taken though a single process in which its volume decreases by .25 m^3 as the temp of the gas rises 2deg C. Which of the following people are more likely to have reached the correct conclusion? a. Bob Identifies this process as adiabatic b. Jill identifies this ...

*November 30, 2010*

**History**

A more unified African American culture began to emerge in the early decades of the nineteenth century because? the Gullah dialect spread to the new slave territories in the Old Southwest. the rapid transfer of slaves from other regions into the Lower Mississippi Valley ...

*November 29, 2010*

**English**

1) lessons, is better 2) is good 3) 2 lessons/2 more hours of lesson 4) good 5) i go to the bathroom where i wash and dress myself (not dressed myself) 6)i get ready for school 7) good 8) good 9) computer lab and fine

*November 14, 2010*

**algebra**

Select the set of equations that represents the following situation: The cost of eleven CDs and twelve DVDs is $150.62; and the cost of one DVDs and twelve CDs is $116.07. How much do a CD and a DVD cost? (Points : 3) 11x + 12y = 150.62; 12x + 1y = 116.07 11x • 12y = 150....

*November 13, 2010*

**physics**

If there are three forces acting on an object, one straight up, one up at an angle to the left (angle unknown) and one up at an angle to the right what direction is the combined force? Is it possible for the combined force of those three forces to be down?

*November 8, 2010*

**Math**

Two sides of a triangle have the same length. The third side measures 4 meters less than twice the common length . The perimeter of the triangle is 16 meters. What are the lengths of the three sides?

*November 7, 2010*

**Business Calculus**

An ice cube that is 3 cm on each side is melting at a rate of 2 cm cubed per minute. how fast is the length of the side decreasing?

*October 21, 2010*

**Science**

that doesnt help me though. i need to know what Describe the role of gravity as the force that governs the movement of the solar system and the universe means.

*September 27, 2010*

**Science**

"Describe the role of gravity as the force that governs the movement of the solar system and the universe." I don't get it.

*September 27, 2010*

**math**

Tyrell says $750 is about $800.Sara says $750 is about $700.who is correct?explain.

*September 22, 2010*

**math**

in which number does 4 have the greatest value 9499 4391 2240 1944

*September 21, 2010*

**Physics**

This should say Physics-Typo error

*September 19, 2010*

**Ohysics**

An airplane flying at 120km/h due west moves into a region where the wind is blowing at 40km/h due east. If the plane's original vecotr velocity is Vplane, what is the expression for the plane's resulting velocity in terms of Vplane. a. 1/3 >Vplane b. 2/3>Vplane ...

*September 19, 2010*

**Physics**

A lightning bug flies at a velocity of 0.25m/s due east toward another lightning bug seen off in the distance. A light breeze blows from the east on the bug at a velocity of 0.25m/s. What is the resultant velocity of the lightning bug? Please direct me to even start-I'm ...

*September 15, 2010*

**Math**

Help! Toshiro Hashimoto invested some money at 4.5% simple interest and $1000 more than four times the amount at 6%. His total annual income for one year from interest on the two investments was $801. How much did he invest at each rate?

*September 15, 2010*

**Language Arts**

I need the complete predicate in this sentence? Ida B. Wells was born into slavery in 1862 in Holly Springs, Mississippi.

*September 9, 2010*

**English**

Could someone help with the main idea of this paragraph? Please and thank you Old Man Warner snorted. 'Pack of crazy fools," he said. "Listening to the young folks, nothing's good enough for them. Next thing you know, they'll be wanting to go back to ...

*September 8, 2010*

**Math**

Thank you so much

*September 7, 2010*

**Math**

Help-I just started Algebra II and I'm lost. What is the solution of 10 = absolute value of 7-3x. Please show steps so I can understand

*September 7, 2010*

**Physics**

I just need to clarify something in my mind- I look at a graph and the position changes from 3 to 8 over a ten second interval, to find total displacement, I just take 8-3 would equal 5 for total displacement, correct? I don't need to bother with the time interval, correct...

*September 6, 2010*

**Chemistry**

What is the pH of a 1.0E-8 M solution of HCl? Please note that you cannot simply add the contribution of H+ ions from the autoproteolysis of water and the contribution from the dissociation of HCl. You will need to use the quadratic equation to solve this problem and report ...

*September 3, 2010*

**Chemistry**

What is the pH (to three figures) of a 0.1 M solution of sodium acetate given that the acid dissociation constant (Ka) of acetic acid is 1.8E-5? Hint: I keep getting 2.87 but its wrong.

*September 3, 2010*

**Math**

y=3x-3.5

*June 10, 2010*

**Global History**

ok thanks jimmy and Ms.Sue

*April 9, 2010*

**trig**

what is the tan of 25 degrees and 01 minute

*April 7, 2010*

**English**

In many works of literature, an individual's encounter with death or destruction ultimately leads to the individual's affirmation of the dignity and worth of human life. What does this quote means and how does this quote relates to Hamlet by William Shakespeare. I have...

*April 6, 2010*

**s.s.**

it says they slowly decliened

*February 21, 2010*

**s.s.**

history idk

*February 21, 2010*

**s.s.**

Axum's conversion to Christianity a. beneficial b. a drawback c. first a drawback then beneficial d. first beneficial then a drawback

*February 21, 2010*

**algebra**

for x-y=3 add y to both sides then subtract three from both sides. For x+4y=9 subtract x from both sides then divide everything by 4.

*February 1, 2010*

**Can't understand trig problem**

An airplane left an airport and flew east 174 miles. Then it turned northward flying along a bearing of N22E. When it was 254 miles from the airport, there was an engine problem and it turned back to take the shortest route possible back to the airport. Find theta, the angle ...

*February 1, 2010*

**Geography**

What climate does the United States not have?

*January 21, 2010*

**physics**

There's a magic ring in a sealed paint can at the bottom of a frozen pond in the middle of a bog. YOu must get the ring via a plan which: gets you and equipment you need across without sinking, cross the frozen pond without breaking through the ice, lift the paint can out ...

*January 19, 2010*

**algebra 2**

X + 2 = - 2

*January 16, 2010*

**algebra 2**

X+2 = 3 - 5

*January 16, 2010*

**Precalculus**

If sinu = -5/7 and pie<u<3pie/2 find 2u Does anyone know the answer to this (not the steps for solving I know that my answer just keeps coming out funny)

*January 13, 2010*

**Precalculus**

what are the zeroes of the graph 2sin(squared)x + cosx-3 = 0

*January 13, 2010*

**american government**

What are the differences and similarities between baltimore country council and the Maryland general assembly

*January 13, 2010*

**precal desperate**

Given sina= 3/4 and cosB = (-5)/13 and this is Quad II find cos(a+B)

*January 13, 2010*

**precalculus**

Given sina= 3/4 and cosB = (-5)/13 and this is Quad II find cos(a+B)

*January 12, 2010*

**algebra**

Which is greater? 7 3/4 or 7 2/3

*January 6, 2010*

**math**

You got the answer pretty much right but a more exact answer would be 8/3 or 2 2/3. Because in decimal form it is actually 2.66666667

*November 29, 2009*

**Calculus - Related Rates**

12mm^2/hr = r2PI dr/dt So 12/2PIr mm^2/hr = dr/dt which is the same as dr/dt = 6/PIr mm^2/hr Why'd you originally say dr/dt= 12/(2r) mm/hr

*November 29, 2009*

**Calculus - Related Rates**

I'm sorry, I'm not following what you did. I get that we know dx/dt = 12mm^2/hr and we want to find dr/dt but I don't know how you linked them together as a function of r. Maybe show me more steps and how you got the derivative dr/dt. Thanks

*November 29, 2009*

**Calculus - Related Rates**

Bacteria are growing in a circular colony one bacterium thick. The bacteria are growing at a constant rate, thus making the area of the colony increase at a constant rate of 12 mm sq. per hour. Find an equation expressing the rate of change of the radius as a function of the ...

*November 29, 2009*

**science**

how do geologists determine the texture of a rock

*October 15, 2009*

**8th grade**

what is gnama artea it means Kings must follow laws too.

*September 21, 2009*

**com130**

. In what situations might an individual writing process be preferable?

*June 24, 2009*

**calculus**

find the integral of square root of 1+x^3 dx or sqrt(1+ x^3)dx

*February 23, 2009*

**calculus help**

find the integral of square root of 1+x^3 dx or sqrt(1+ x^3)dx

*February 23, 2009*

**calculus i need help please**

evaluate: integration of x^2 (square root of (1-2x^3))dx

*February 19, 2009*

**calculus**

thanks

*February 19, 2009*

**calculus**

evaluate: integration of x^2 (square root of (1-2x^3))dx

*February 19, 2009*

**Government**

How has the clean air act increased the power of the federal government relative to the power of the state governments?

*February 13, 2009*

**Macro Economics**

Can it be considered acceptable to policy makers to have about 7 million people classified as unemployed in the U.S.? Explain.

*September 30, 2008*

**Macro Economics**

I meant frictional unemployment rate

*September 29, 2008*

**Macro Economics**

Does anyone know how to calculate the frictional rate of employment...given the following information... The structural unemployment rate of 2.8%, actual unemployment rate of 7% and cyclical unemployment is 2.0% I just need to know the formula to use??

*September 29, 2008*

**beginning chemistry**

calculate the volume of 750.0g of gold.

*March 11, 2008*

**math grade 3**

need to draw data sets to find the mean. I know how to use this putting the numbers in order from least to greatest, but how do I draw this?

*September 20, 2007*

**Algebra**

Thank you so much! :)

*August 24, 2007*

**Algebra**

I still don't get it! My brain is burnt right now.

*August 24, 2007*

**Algebra**

Gabe lives fifteen miles from school and the bus stops seven times at three minutes each between his house and school. The bus arrives at his house at 7:30. Gabe's friend Aaron lives 8 miles from school and the bus stops four times at 2 minutes each between his house and ...

*August 24, 2007*

**Algebra**

Ann sells apples and Beth sells oranges. Today, half the number of apples than Ann sold was fifteen less than thrice as much the number of oranges that Beth sold. I just want it to know; how do I convert it into an algebraic expression or equation? Is confusing and I don't...

*August 21, 2007*

**Algebra**

so it will be like this? 1/2 A= 3B - 15

*August 20, 2007*

**Algebra**

Thank you. I can work on it now. :)

*August 20, 2007*

**Algebra**

Ann sells apples and Beth sells oranges. Today, half the number of apples than Ann sold was fifteen less than thrice as much the number of oranges that Beth sold. Can someone explain to me what this means and how to do it pretty please? I really need help on this one. Can ...

*August 20, 2007*