Friday

February 24, 2017
Total # Posts: 111

**Chemistry**

What volume (in mL) of 1.0 M HCl is required to prepare 500 mL of pH 7.76 buffer using triethanolamine that is 0.020 M in both triethanolamine and triethanolammonium ion?

*November 15, 2016*

**Graph Theory**

Let S be a sequence of exactly one positive integers, n. what is the least number of 1s needed to be added to make it graphical?

*October 28, 2016*

**Chemistry**

In the laboratory you will be provided with a 1.0 x 10-5 M primary stock solution of fluorescein (MW=332.31g/mol). The calibration curve should include a blank, 0.025, 0.05, 0.075, 0.10, 0.15, and 0.25 micromolar fluorescein solutions. Since you will be using 25 mL volumetric ...

*October 18, 2016*

**Math**

A car travels at a steady rate of 55 mph. If the car travels for three hours nonstop, what are the domain and range of the distance function during the trip?

*April 27, 2016*

**Math**

If a person is charged 1.5 cents per mile,how much will he have to pay after he drives one thousand miles?

*February 18, 2016*

**Science**

The movement of air and water through a soil is influenced most by the soil’s ______

*February 16, 2016*

**maths literacy, economics, business studies, tourism, English, Afrikaans, L.O**

I don't know what to study after grade 12 or where to study I don't have a career choices can someone please help me

*January 28, 2016*

**math**

write the expression in expand form (4.2z)(-5y-3)

*November 11, 2015*

**Physics**

In the figure, a thin uniform rod of mass m = 3.05 kg and length L = 1.11 m rotates freely about a horizontal axis A that is perpendicular to the rod and passes through a point at a distance d = 0.201 m from the end of the rod. The kinetic energy of the rod as it passes ...

*July 25, 2015*

**Math**

You have 100 pieces of candy in five bowls. The sum of candy in bowl a and bowl b is 30 pieces. The sum of candy in bowl b and c is 36 pieces. The sum of candy in bowl c and bowl d is 49 pieces of candy. The sum of bowl d and bowl e is 47 pieces of candy. How many pieces of ...

*February 1, 2015*

**Chemistry**

A liquid has a delta(Hvap) of 35.5 kJ/mol and a boiling point of 122 C at 1.00atm. What is its vapor pressure at 113 C?

*December 9, 2014*

**Chemistry**

At a given temperature and pressure how does the magnitude of the heat of vaporization of a substance compare with that of its heat of condensation?

*December 9, 2014*

**Chemistry**

Which solution has the lower freezing point? 11.0 g of methanol in 100. g of water OR 22.0 g of ethanol in 200. g of water?

*December 8, 2014*

**calculus**

object 380 ft above surface of globe. Horizon is 65.3 degrees from object. What is circumference of globe?

*November 15, 2014*

**Science! Help!!**

I'm from there to. But is it C, B or A?

*September 25, 2014*

**MATH**

WHAT DOES THIS SERVICE COST?

*February 19, 2014*

**MATH TUTOR**

HOW MUCH IS YOUR SERVICE?

*February 19, 2014*

**Calc 2**

What is the lim of the square root of x times sin of (1/x) as x approaches infinity

*February 19, 2014*

**Environmental Engineering**

The EPA requires hazardous waste incinerators to meet a standard of 99.99% destruction and removal of hazardous constituents injected into the incinerator. Determine the allowable quantity of contaminant in the exit stream if the incinerator is burning 1.0000 g/s of hazardous ...

*January 15, 2014*

**chemistry**

Thank you for your help! For part c, I'm not sure what you mean finding Na from NO3^-?

*January 13, 2014*

**chemistry**

You are tasked with preparing a 500mL nutrient solution containing 5mg/L of phosphorous (P), 3mg/L nitrate (NO3 -) and 100 mg/L chloride (Cl-). To make this solution, you have powdered sodium chloride, a 100 mg/L solution of phosphorus, a 1000 mg/L of sodium nitrate (NaNO3) ...

*January 13, 2014*

**Solving Rational Equations**

60

*October 23, 2013*

**Math**

what is the present value of $329 a year for 6 years at a 12 percent discount rate?

*June 17, 2013*

**Math**

12 years at 5% compounded annually what is the future value of $557?

*June 17, 2013*

**stat**

When rolling a die, is this an example of a discrete or continuous random variable?

*June 17, 2013*

**science**

At time t =0, the current to the dc motor is reversed, resulting in an angular displacement of the motor shaft given by è = (198 rad/s)t – (24 rad/s2)t2 – (2 rad/s3)t3 (15 marks) a. At what time is the angular velocity of the motor shaft zero? b. Calculate the...

*April 27, 2013*

**physics**

2. At time t =0, the current to the dc motor is reversed, resulting in an angular displacement of the motor shaft given by θ = (198 rad/s)t – (24 rad/s2)t2 – (2 rad/s3)t3 a. At what time is the angular velocity of the motor shaft zero? b. Calculate the angular ...

*April 27, 2013*

**life orientation**

Identify one human factor that causes ill health;accident and disaster.

*April 18, 2013*

**math**

The variance of the standard normal distribution is equal to

*April 11, 2013*

**math**

If the highest score is100 and the average score for12 students is 95. What is the lowest score in order to get the average of 95?

*February 5, 2013*

**Physics**

The electric field intensity at a point 2 meters from the surface of a uniformly charged conducting sphere is 1920 N/C. At a point 4 meters from its center, the electric field intensity is 3000 N/C. a.) Determine the radius of the sphere. Determine the electric field intensity...

*February 4, 2013*

**Physics**

The intensity of the light isn't halved after it passes through each filter? That's what I don't understand. Thank you for your help!

*December 12, 2012*

**Physics**

There are two polarizing filters that are out of alignment by 30 degrees. If the light of intensity 1.00 W/m^2 and initially polarized half-way between the two filters passes through the two filters, what is the intensity of the transmitted light? I know the answer is 0.700 W/...

*December 12, 2012*

**hvac school**

What temp would a fixed volume of gas need to be heated in order to double its pressure if it starts out at 25?

*November 30, 2012*

**Physics**

thank you!

*October 24, 2012*

**Physics**

A fully charged 90-µF capacitor is discharged through a 60-Ω resistor. How long will it take for the capacitor to lose 80% of its initial energy? I know energy is given by E(t)=q(t)^2, but beyond that I really don't know how to solve this. Any suggestions are ...

*October 24, 2012*

**Physics**

Thamk you for your help.

*September 19, 2012*

**Physics**

A beam of X-rays with a wavelength ƒÜ of 0.179nm is directed at an iron crystal whose planes have a spacing of 0.1013nm. How many diffraction peaks (each arising from a different order n) are possible? I'm really not sure how to go about solving this. Any help is...

*September 19, 2012*

**science**

What cellular structures must an angiosperm have to survive?

*August 28, 2012*

**ALGEBRA**

1.2G DIVIDED BY 3CM TO THE THIRD POWER

*August 26, 2012*

**physics**

thank you for your help!

*July 23, 2012*

**physics**

The label on a soft drink states that 11 fl. oz (325 g) provides 285 kcal. The drink is cooled to 12.0°C before it is consumed. It then reaches body temperature of 37°C. Find the net energy content of the drink. (Hint: You can treat the soft drink as being identical to...

*July 23, 2012*

**physics**

thank you!

*July 20, 2012*

**physics**

A uniform brass disk of radius R and mass M with a moment of inertia I about its cylindrical axis of symmetry is at a temperature T = 45 °C. Determine the fractional change in its moment of inertia if it is heated to a temperature of 125 °C. (The linear expansion ...

*July 20, 2012*

**Physics**

thank you very much!

*July 17, 2012*

**Physics**

A sinusoidal wave traveling on a string is moving in the positive x-direction. The wave has a wavelength of 8 m, a frequency of 60 Hz, and an amplitude of 9 cm. What is the wave function for this wave? (Use any variable or symbol stated above as necessary.) I think the ...

*July 17, 2012*

**Physics**

A particular steel guitar string has mass per unit length of 1.79 g/m. and tension of 61.9 N. For the wave speed to be increased by 1.9%, how much should the tension be changed? I tried increasing the wave speed (186 m/s) by 1.9%, plug that into v=sqrt(T/linear mass density), ...

*July 17, 2012*

**Physics**

Thank you so much for your help!

*July 13, 2012*

**Physics**

A mass m = 13 kg is connected to two different springs, one on the left and another on the right. It is displaced a distance x to the right from its equilibrium position. (Take k1 = 115 N/m and k2 = 198 N/m.) (a) What is the net force acting on the mass? (Use any variable or ...

*July 13, 2012*

**Physics**

Thank you for your help!

*July 13, 2012*

**Physics**

The motion of a block-spring system is described by x(t) = A sin(ùt). Find ù, if the potential energy equals the kinetic energy at t = 6.11 s. I'm really not sure how to solve this. It seems that you need more information, either x or A? I appreciate any help...

*July 13, 2012*

**Physics**

A 3-kg mass attached to a spring with k = 130 N/m is oscillating in a vat of oil, which damps the oscillations. (a) If the damping constant of the oil is b = 19 kg/s, how long will it take the amplitude of the oscillations to decrease to 1% of its original value? (b) What ...

*July 12, 2012*

**Engineering**

A certain OTA with a transconductance of 5000 µS has a load resistance of 10 kÙ. If the input voltage is 100 mV, what is the output current? What is the output voltage?

*April 5, 2012*

**math**

Unless your teacher gives you 5700 as the half life.

*April 4, 2012*

**Chemistry**

In reality you probably could, however it is not good science as it has been considered to be contamined or already used and a new substance or solution should be obtained. I know this is wasteful but, that is just how it is.

*March 11, 2012*

**Chemistry**

I got 0.02 g is this right?

*March 11, 2012*

**Chemistry**

just steps is all i really need i think i need the molecular weights first then just simple molarity am i correct?

*March 11, 2012*

**Chemistry**

Calculate the amount of Na2HPO4*7H2O in grams needed to make 50 mL of a 0.40 M solution. I think this is dealing with molarity but i cant figure it all out for some reason? Help would be greatly appreciated.

*March 11, 2012*

**Maths**

N+10N=0

*February 2, 2012*

**algebra**

Writ an algebric expression for this statement.Ama is N year old now.How old will she be in 10 years.

*February 2, 2012*

**Physics**

The initial velocity of a 2.04 kg block sliding down a frictionless inclined plane is found to be 1.24 m/s. Then 1.23 s later, it has a velocity of 6.70 m/s. What is the angle of the plane with respect to the horizontal? im lost.....

*January 30, 2012*

**physics**

An 88kg fisherman jumps from a dock into a 131kg rowboat at rest on the west side of the dock. If the velocity of the fisherman is 4.7m/s to the west as he leaves the dock, what is the final velocity of the fisherman and the boat. East is positive.

*January 16, 2012*

**math**

In a triangle, between J and K is 30in and between J and L is 25 degree, what is the measure of <K ?

*December 7, 2011*

**Trig!**

Sin2x

*September 27, 2011*

**geometry**

88

*September 12, 2011*

**Math**

16/19. Cant be reduced anymore.

*August 18, 2011*

**Math**

17/21. You take away the negative. (Only in some cases though)

*August 18, 2011*

**geometry**

A rectangular prism has dimensions of x + 1, x - 1, and x. Write an expression for the total volume of the prism.

*June 10, 2011*

**statistics**

) If this data were normally distributed, determine the probability that the sample mean would be as far away from the population mean or more so

*April 17, 2011*

**Chemistry**

How many mL of 1.211 Molarity sulfuric acid is required to completely neutralize 10.0 mL of 3.210 Molarity calcium hydroxide?

*March 23, 2011*

**Chemistry**

Give the molecular, complete ionic, and net ionic equations for the reaction of ammonia with hydrochloric acid.

*March 23, 2011*

**Chemistry**

Give the molecular, complete ionic, and net ionic equations for the reaction of sulfuric acid and barium hydroxide.

*March 23, 2011*

**Chemistry**

What is the concentration of an acetic acid solution if 11.2 mL of 1.002 Molarity sodium hydroxide solution is needed to completely neutralize 5.1 mL of the acid?

*March 23, 2011*

**Chemistry**

How many grams of water are produced from the reaction of 1L of 2 molarity hydrochloric acid with 1L of 2 Molarity barium hydroxide?

*March 23, 2011*

**Chemistry**

Give the molecular, complete ionic, and net ionic equations for the reaction of phosphoric acid and magnesium carbonate.

*March 23, 2011*

**Chemistry**

According to the Bronsted-Lowry definition of acids and bases, is water an acid or base? Provide examples to support.

*March 23, 2011*

**Chemistry**

Give the molecular, complete ionic, and net ionic equations for the combination of potassium chloride and magnesium sulfate.

*March 23, 2011*

**Chemistry**

Is it possible to have an acid/base reaction and produce a precipitate as a product as well? If yes, provide an example.

*March 23, 2011*

**Chemistry**

Does the mixing of copper (I) nitrate with sodium iodide produce a precipitate? If so, give the molecular equation.

*March 23, 2011*

**Chemistry**

Give the molecular, complete ionic, and net ionic equations for the reaction of barium nitrate and sodium sulfate.

*March 23, 2011*

**Chemistry**

Most chlorides are soluble in water. Give all of the formulae for the insoluble chlorides.

*March 23, 2011*

**algebra**

(5ay)exponent 3

*February 28, 2011*

**science**

Calculate the pH of a solution created by mixing 200.0 mL of 0.400 M acetic acid and 200.0 mL of 1.00 M sodium acetate. Hint: The instant the two solutions are mixed what are the initial concentrations of each?

*February 14, 2011*

**algebra**

Is (3, 2) a solution to this system of equations? 8x + 7y = 37 2y = 4x - 2 (duh...a+ yes

*February 2, 2011*

**math**

Billy has a bag of candy that contains 13 red pieces, 9 green pieces, 3 yellow pieces, and 7 orange pieces. If Billy reaches into the bag without looking, what color is he least likely to get?

*January 9, 2011*

**Pre-Calculus**

. Margaret is planning to invest up to $22,000 in certificates of deposit at City Bank and People’s Bank. She wants to invest at least $2,000 but no more than $14,000 at City Bank. People’s Bank does not insure more than a $15,000 investment, so she...

*December 2, 2010*

**Math**

A point is sliding along a curve y^2 = 1 + cos^3(2x) at whatever speed (even depending on time). Compute the ratio of the rates of change of the vertical and horizontal coordinate with respect to time when the point is at (x, y).

*November 12, 2010*

**4th grade math**

62

*October 29, 2010*

**Chemistry**

A 325.0-g piece of gold at 427°C is dropped into 200.0 g of water at 22.0°C. (The specific heat of gold is 0.131 J/g°C.) Calculate the final temperature of the mixture. (Assume no heat loss to the surroundings.) Can you please outline step by step how i would ...

*October 22, 2010*

**college algebra**

What is 1.7^0.3326 = ?

*September 12, 2010*

**chemistry**

M=3.65*10^-5

*June 25, 2010*

**critical thinking**

How can I apply critical thinking when evaluating, articles, advertising, media and conversations?

*October 9, 2009*

**alcohool beverages**

alcohool beverages

*August 24, 2009*

**The Gourmet Kitchen**

the Gourmet Kitchen

*August 24, 2009*

**pre- algebra**

3x = 21 3x/3 = 21/3 x=7

*July 19, 2009*

**College physcial science**

40000j

*April 25, 2009*

**social study**

Complete a venn digram to compare and contrast

*August 21, 2008*

**Social Study**

two views of reconstruction

*August 21, 2008*

**english**

what shows phillip prejudice?

*April 28, 2008*