Tuesday

December 6, 2016
Total # Posts: 854

**Math**

Jessica played on the school chess team last year. She won 65% of the games She played. If She won 13 games, How many did She playi?

*November 17, 2016*

**Calculus - Word Problems**

Suppose a spherical snowball is melting at a constant rate of 0.20in per hour. How fast is the volume changing when the radius is 10in?

*November 14, 2016*

**Calculus - Optimization **

The post office ships a package using large package rates if the sum of the length of the longest side and the girth (distance around the package perpendicular to its length) is greater than 84in and less than or equal to 108in. Suppose you need to ship a package that is 40in ...

*November 14, 2016*

**Calculus**

The post office ships a package using large package rates if the sum of the length of the longest side and the girth (distance around the package perpendicular to its length) is greater than 84in and less than or equal to 108in. Suppose you need to ship a package that is 40in ...

*November 14, 2016*

**Chemistry**

Consider the following reaction. 2Fe2O3 --> 4Fe+3O2 Hrxn=+824.2 The Formation of 21.0 of Fe results in 1)the release of 77.5 kJ of heat. 2)the absorption of 3.10 × 102 kJ of heat. 3)the release of 4330 kJ of heat. 4)the absorption of 77.5 kJ of heat. 5)the release of ...

*October 30, 2016*

**Math**

I never ask for help like this but i really need it im so lost and have more to do than i can handle

*October 27, 2016*

**Math**

Lesson 8: Solving Inequalities Unit Test CE 2015 Algebra 1 Unit 4: Solving Inequalities i need answers im 9 lessons behind in math and my mom just had surgery and the house is a mess if anyone understands please help!!!! ): i just dont have time

*October 27, 2016*

**math**

The measures of the three angles of a triangle are given. Find the value of x and state whether the triangle is acute, obtuse, or right. x + 10, x − 20, x + 25 I got x is 55 and it is an acute angle. Is that correct?

*October 10, 2016*

**Pre-Calculus**

A hemispherical bowl with a 30-centimeter radius contains some water, which is 12 centimeters deep. Find the volume of the water.

*October 10, 2016*

**Math**

what is the largest 3 digit even number you can make with the digits 1,2, and 3?

*September 27, 2016*

**vocab help**

Ice floats in water just like wood floats on : A. Water B. Ice C. Wood D. On the bottom My Answer is A

*September 1, 2016*

**Maths (quadratic equation) need help**

In an unknown fraction the denominator is one more than twice the numerator. When 2 1/10 is added to this fraction, the result is equal to the reciprocal of the unknown fraction. Find the unknown fraction. (Hint; the the numerator of the fraction to be the x)

*May 31, 2016*

**help science **

3 simple steps for DNA duplication I have found so many answers but cant get a concise one. 1. separation - of 2 dna strands unzips ? 2. duplicates ? 3. zips back up ? and then a simple sentence about each

*May 29, 2016*

**7th grade science final **

review Question -- 3 simple steps for DNA duplication I have found so many answers but cant get a concise one. 1. separation - of 2 dna strands unzips 2. duplicates 3. zips back up and then a simple sentence about each

*May 29, 2016*

**Math Trigonometry**

Thank you a lot you saved my life.

*May 19, 2016*

**Math Trigonometry**

A plane flies in a direction of 85° from Chicago. It then turns and flies in the direction of 200° for 150 miles. It is then 195 miles from its starting point. How far did the plane fly in the direction of 85°? I am confused about aereal navigation. Can someone ...

*May 19, 2016*

**Math**

The student mr. Davis class either walk or ride the bus to school the number of students ride the bus is a tenant in the number of students who walk is 12 is there a 450 students in the school how many students total can you expect to ride the bus

*May 14, 2016*

**scte**

a 90 volt Hz source is connected to 0.1 Henry inductor.what is the current through the inductor?

*April 26, 2016*

**LO **

a newspaper article to warn people against engaging with fraud

*April 24, 2016*

**A.P. Chem **

Based on like dissolve like, determine if these compounds will be more soluble in water or an organic solvent. 1) Sodium Butyrate I think Water 2) Phenol I think organic 3) Aniline I think water 4) Sodium phenoxide I think water

*April 12, 2016*

**Math**

Show using integration by parts that: e^3x sin(2x)dx = 4/26 e^3x (3/2 sin(2x) - cos(2x)) +c Bit stuck on this. Using rule f udv = uv - f vdu u = e^3x dv + sin(2x)dx f dv = v du/dx = 3e^3x v = -1/2 cos(2x) so uv - f vdu: = (e^3x)(-1/2 cos(2x)) - (-1/2 cos(2x))(3e^3x) Don't ...

*March 24, 2016*

**Physics**

A 5 kg block is being pulled on a frictionless surface by a string at an angle of 30o to the horizontal. The tension in the string is 30 N. What is the total work done on the block as it moves a distance of 10 m?

*March 21, 2016*

**calculus **

the vector function r(t)=< 5 sin t, 3 sec t > , represents the position of a particle at time t. find the velocity v (t) and acceleration a (t). I don't know how to solve it without the t given. Please help

*March 21, 2016*

**Calculus**

Rectangular sheet of metal 750mm by 300mm - find length of the sides of the squares to give max volume to the box, and find maximum volume of the box?

*March 19, 2016*

**Chemistry **

If I am doing a fractional distillation, is the temperature of the first few drops of the distillation considered part of the boiling range? Or do you wait until later in the distillation?

*March 16, 2016*

**Chemistry**

Okay, so then the volume percent is 10/20 and 8.4/20?

*March 14, 2016*

**Chemistry**

What do you mean? It doesn't have any information about the water added? So is the percent volume 10/20 and 8.4/20, or do I need water for that too? I'm sorry but you've confused me more than I already am.

*March 14, 2016*

**Chemistry **

You start with a 20ml mixture of two compounds. After distillation you end up with 10ml of distillate 1 and 8.4ml of distillate 2. What is the relative volume percent of each compound in the pre-distilled mixture? (Do I just do: volume percent of mixture1=10/20 and volume ...

*March 14, 2016*

**Science**

Is Gc (32.2 lbmft/lbfs^2) equal to gravity? I think it is, but I'm kinda confused about the whole concept. Could someone explain it to me? Thank you very much.

*March 9, 2016*

**Physics**

Is Gc (32.2 lbmft/lbfs^2) equal to gravity? I think it is, but I'm kinda confused about the whole concept. Could someone explain it to me? Thank you very much.

*March 9, 2016*

**Math**

I'm not really sure what you're trying to solve for but heres what I think. 12 (.5%)•(.5/.75) =(0.06)•(0.67) = 0.0402 and maybe multiply by 100 to get = 4.02

*March 9, 2016*

**science**

22.98977 amu

*March 9, 2016*

**Chemistry**

Why is methanol a good solvent to recrystallize biphenyl?

*February 25, 2016*

**MATHS**

In a class of 30 learners,17 play football,15 play vollyball,12 play rugby.9 learners play vollyball only and 3 play rugby only.If all learners play at least one of the three sports.Use a venn diagram to find the number of learners who pray only vollyball and rugby

*February 17, 2016*

**Physics **

A 6.80 x 10^4 kg space shuttle moving at 7.90 x 10^4 m/s reenters the earth's atmosphere 80.0 km above the earth's surface. What is the shuttle's total mechanical energy with respect to earth's surface? I know the answer is E= 2.173 x 10^12J But I don't ...

*January 27, 2016*

**Economics Macro**

Suppose that real GDP per capita in the United States is $49,000. If the long-term growth rate of real GDP per capita is 1.6% per year, how many years will it take for real GDP per capita to reach $98,000?

*January 25, 2016*

**MATH**

105 calories

*January 25, 2016*

**Health**

These were all correct except for number 4. It's D for number 4.

*January 6, 2016*

**Statistics**

I found the chi-square table, what would I put for the number of cells ? Im a little lost thanks :)

*December 23, 2015*

**Statistics**

On the third day of Statistics, my teacher gave to me….three French hens. Because she is in a hurry, she randomly selects three pets from the local pet store. Find the probability that she selected three French hens. Hens Chickens French 10 20 American 30 40 In order to ...

*December 23, 2015*

**mechanics**

Short column of rectangular cross section 160mm by 60mm carrying point load of 40 KN at max eccentricity position along the longer axis so that no tensile stress is applied. I worked out max eccentricity as 26.66 mm from RH and LH, and compressive stress as 4.167 MPa. The ...

*November 26, 2015*

**Mechanical engineering**

An I section beam of 4m length with end supports is required to carry a point load of 50 KN at its mid pint. The maximum bending stress is limited to 85 MPa, and Modulus of Elasticity of the steel s 200 GPa. Evaluate maximum bending moment that will be applied, and state its ...

*November 26, 2015*

**Algebra 2**

Solve system by substitution or elimination x+4y=13 2x+3y=6

*November 13, 2015*

**history**

How did 18th- and 19th-Century European imperialism help to cause nationalism in Asian and African countries? A) It promoted free trade among the imperial colonies. B) It established Christianity as the common religion. C) It caused intense patriotic feelings toward the ...

*November 6, 2015*

**Algebra**

If Angela runs up 5 steps of an escalator, it takes her 40 seconds to reach the top of the escalator. If she runs up 14 steps of the escalator, then it takes her only 26 seconds to reach the top. How many seconds would it take Angela to reach the top if she did not run up any ...

*September 11, 2015*

**Algebra**

If Angela runs up 5 steps of the escalator, then it takes her 40 seconds to reach the top of the escalator. If she runs up 14 steps of the escalator, then it takes her only 26 seconds to reach the top.

*September 11, 2015*

**Presbyterian Boys' Senior High**

Q, P and R are three villages on a level ground. Q is 4km on a bearing of 040° from P, while R is 3km on a bearing of 130° from Q. Calculate the distance and bearing of P from R.

*September 4, 2015*

**math**

Sarah Meeham blends coffee for Tasi-Delight. She needs to prepare 140 pounds for blended coffee beans selling for $5.07 per pound. She plans to do this by blending together a high-quality bean costing $6.50 per pound and a cheaper bean at $2.50 per pound. To the nearest pound...

*July 14, 2015*

**Maths**

Have a question on complex numbers. Z1= 1+j2, Z2= 2+j5 Find total impedance in Cartesian and polar form of two impedances in parallel: 1/ZT = 1/Z1 + 1/Z2 I get to 39/58 + 83/58 j but then get a bit lost.

*May 20, 2015*

**chemistry**

What mass of solute is contained in 250 mL of 0.895 M NH4Cl? I think that this is a molarity question. Molarity = mass of solute/volume of solution in L. 1 mL = 0.001 L so 250 mL * 0.001 L = 0.25 L 0.895 M = X (mass of solute)/ 0.25 but since the answer is to be in grams, I ...

*May 7, 2015*

**Economics**

can someone help me put (yuan depreciates against the dollar into one stanza of a song.

*May 5, 2015*

**Science**

Yes, the answers to this entire quick check were 1.A 2.D 3.C 4.B

*May 4, 2015*

**physics**

A fixed mass of gas has a pressure of 8700 Pa, a volume of 10.5 m3 and temperature of 68 °C. The pressure and volume of the gas are changed to 9 243 Pa and 14.4 m3. The new temperature of the gas is

*May 4, 2015*

**chemistry**

An atom whose nucleus contains 7 neutrons and which has a mass number of 12 is an isotope of what element?

*April 27, 2015*

**chemistry**

What is the approximate effective nuclear charge for arsenic ?

*April 27, 2015*

**chemistry**

q4 What element has the greatest first ionization energy? Li Na K Rb Cs

*April 27, 2015*

**Science**

The answers to the severe weather quiz are the following. I just took this quiz and I got a 100% A. Trust me guys. 1.C 2.C 3.B 4.B 5.A 6.B 7.B 8.D 9.C These answers will give you a 100.

*April 19, 2015*

**chemistry**

Consider an electrochemical cell based on the reaction: 2H+(aq) + Sn(s) = Sn2+(aq) + H2(g). Which of the following actions would NOT change the measured cell potential? lowering the pH in the cathode compartment addition of more tin metal to the anode compartment any of the ...

*April 19, 2015*

**chemistry**

What is the oxidation state of the vanadium atom in VO4−

*April 16, 2015*

**chemistry**

Consider an electrochemical cell based on the reaction: 2H+(aq) + Sn(s) = Sn2+(aq) + H2(g). Which of the following actions would NOT change the measured cell potential? lowering the pH in the cathode compartment addition of more tin metal to the anode compartment any of the ...

*April 16, 2015*

**chemistry**

Which element is reduced in the unbalanced reaction below? I− + MnO4− + H+ = I2 + MnO2 + H2O I no reduction occurred in this reaction O H Mn

*April 16, 2015*

**chemistry**

How many electrons does the Au+ ion have ? Enter an integer below without any letters or symbols.

*April 15, 2015*

**Physics**

I have a question on fluids. Water in a section 1.2m wide, 2m high. retained by sluice gate that can pivot about its base. There is a retaining cable at the top of the gate. Determine tension in the retaining cable at the top of the gate when the depth of water is 1.8m. ...

*April 13, 2015*

**Mechanical Principles**

I have a question on fluids. Water in a section 1.2m wide, 2m high. retained by sluice gate that can pivot about its base. There is a retaining cable at the top of the gate. Determine tension in the retaining cable at the top of the gate when the depth of water is 1.8m. ...

*April 13, 2015*

**Physics**

Is this correct?? Metal block weighs 500g in air and 446g completely submerged in water. Calculate density and relative density. Density of water = 1000kg/m3 BF (Buoyant force) will be 500g-446g = 0.54 g (or 0.054 kg). For volume: If BF = Density(water)*V*g then V = BF/density...

*April 10, 2015*

**Chemistry**

Laughing gas (nitrous oxide, N2O) is sometimes used as an anesthetic in dentistry. It is produced when ammonium nitrate is decomposed according to the reaction NH4NO3(s) −! N2O(g) + 2H2O(§¤) . How much NH4NO3 is required to produce 54.5 g of N2O? Answer in ...

*April 9, 2015*

**Chemistry**

027 (part 1 of 3) 10.0 points Copper reacts with silver nitrate through single replacement. If 3.03 g of silver are produced from the reaction, how much copper(II) nitrate is also produced? Answer in units of mol. 028 (part 2 of 3) 10.0 points How much Cu is required in this ...

*April 9, 2015*

**Chemistry**

Calculate the mass of water formed by the complete reaction of 572 g of propane (C3H8) with excess oxygen. (Write a balanced equation.) Answer in units of g.

*April 9, 2015*

**Mechnical principles**

Mtal block weighs 500g in air and 446g completely submerged in water. Calculate density and relative density. I know relative density is density of material/density of water (1000kg/m-3)

*April 9, 2015*

**chemistry**

At a certain elevation, the boiling point of water is 98.5°C. How much energy is needed to heat 35.0 mL of water to the boiling point at this elevation if the water initially was at 23.4°C? (Cp=75.38J/(mol*C), d= 1.00g/mL)

*April 1, 2015*

**Calculus 1**

How do you find the derivative of 1/3(x^2+2)^3/2 ? Please help

*March 31, 2015*

**physics**

A 5.0 Ω resistor, a 9.0 Ω resistor, and a 12.0 Ω resistor are connected in parallel across a 24.0 V battery. a) What is the equivalent resistance of the circuit? Answer in units of Ω b) What is the current in the 5.0 Ω resistor? Answer in units of A

*March 23, 2015*

**chemistry**

The average swimming pool has a volume of about 28,000 gallons. Suppose a swimming pool was filled with pH 7.00 water. However, you need to adjust the pH to 4.75. How much acid pool acid (which is 1.00 M HCl) do you need to add to the pool? The units are liters. convert ...

*March 21, 2015*

**chemistry**

You need to determine the pKa of a weak, monoprotic acid. You add 0.500 moles of the acid to 1.00 L of water. The resulting pH was 1.87. What is the pKa of this weak acid? You may ignore the autoionization of water. 2.74 3.43 5.38 2.01 1.87

*March 21, 2015*

**chemistry**

ok so i think its hcl/nacl

*March 21, 2015*

**chemistry**

All of the following acid-base pairs are examples of buffers EXCEPT: (Question from "Cracking the MCAT, 2010-2011 edition" by The Princeton Review) HCl/NaCl CH3CO2H/NaCH3CO2 HF/NaF H2CO3/NaHCO3 I chose ch3co2h/nach3co2

*March 21, 2015*

**chemistry**

is the answer 9.86923

*March 21, 2015*

**chemistry**

What is the pH of 500 mL of water that had 0.00150 grams of NaOH added to it? The units are pH units with an error interval of 0.1 units. 0.00150 divided by 40NaOH 3.75e-5 divided that by 500= 7.5e-8 -log7.5e-8 =7.12 im lost on the last step

*March 21, 2015*

**chemistry**

The Ka of hypochlorous acid (HClO) is 3.00×10-8 at 25.0°C. Calculate the pH of a 0.0385 M hypochlorous acid solution. a.1.41 b.7.52 c.-1.41 D.4.47 E. 8.94 I got B 7.52 but i feel like im wrong

*March 21, 2015*

**chemistry**

A 300 mL solution of 0.0500 M HCl is titrated with 1.00 M KOH. How many mL of the KOH solution will be needed to reach the equivalence point of this titration? A.5 mL B.10 mL C.50 mL D20 mL E15 mL The answer i got was E. 15ml

*March 21, 2015*

**chemistry**

Which of the following acids is expected to be the strongest acid? CH2F-COOH CF3-COOH CH3-COOH CCl3-COOH CBr3-COOH i chose ccl3-cooh

*March 21, 2015*

**chemistry**

Which of the following chemicals are bases or can behave like bases? You may select more than one compound. KOH PO43- NH3 F-

*March 21, 2015*

**chemistry**

Which of the following chemicals are bases or can behave like bases? You may select more than one compound. Cu2+ RbOH CH3COO- Br-

*March 21, 2015*

**chemistry**

Which of the following chemicals are strong bases? You may select more than one compound. CH2=CH2 Ca(OH)2 NH3 RbOH

*March 21, 2015*

**chemistry**

I think i figured it out 0.0385 change -x. . . . .. . +x. . . .+x at equilibrium 0.0385-x. .. x..... . .x Ka = 3.0 x 10^-8 = [H+][ClO-]/ [HClO]= (x)(x)/ 0.0385-x x = [H+]= 3.4 x 10^-5 M pH = - log 3.4 x 10^-5=4.5 Im going with D now

*March 21, 2015*

**chemistry**

The Ka of hypochlorous acid (HClO) is 3.00×10-8 at 25.0°C. Calculate the pH of a 0.0385 M hypochlorous acid solution. A.1.41 B.7.52 C.-1.41 D.4.47 E.8.94 I chose B

*March 21, 2015*

**Science**

Haylee is correct.

*March 19, 2015*

**Tech Ed**

Answers to this are 1. B. 2. A & D. 3. A & B. I got 100% with these answers.

*March 16, 2015*

**physics**

How many kilometers would you have to go above the surface of the earth for your weight to decrease to 39{\rm \\%} of what it was at the surface? Express your answer using two significant figures.

*March 9, 2015*

**physics**

A highway curve with radius 1000ft is to be banked so that a car traveling 56.0mph will not skid sideways even in the absence of friction At what angle should the curve be banked?

*March 9, 2015*

**Physics**

A baseball player with a mass of 79 kg slides into homeplate. The coefficient of kinetic friction between the player and the ground is μk = 0.632. If the player comes to rest after 1.04 s, what is his initial speed?

*March 4, 2015*

**Calculus Physics**

help anyone

*March 2, 2015*

**Calculus Physics**

Imagine a spaceship on its way to the moon from the earth. Find the point, as measured from the center of the earth, where the force of gravity due to the earth is balanced exactly by the gravity of the moon. This point lies on a line between the centers of the earth and the ...

*March 2, 2015*

**Calculus Physics**

A glass of orange juice is on the floor of a subway car traveling along a straight path at constant velocity. Everything's fine. The coefficient of static friction between the glass and the floor is 0.32. The subway suddenly accelerates forward. What is the maximum ...

*March 2, 2015*

**chemistry**

One of the ways to produce iron is to take iron(II) oxide and react it with carbon monoxide to get pure iron and carbon dioxide. The reaction is FeO(s) + CO(g) = Fe(s) + CO2(g). What is the partial pressure of CO2(g) if 2.00 atm of CO and excess iron(II) oxide are used to ...

*February 28, 2015*

**chemistry**

Lead iodide is a relatively insoluble compound. It can dissolve from the solid phase into the aqueous phase with a Keq of 0.00027. If the concentration of lead iodide in the aqueous phase 0.125 M, then: a. we need more information to determine the progress of the reaction. b. ...

*February 28, 2015*

**chemistry**

Equilibrium is: a dynamic condition in which the concentration of the reactants is equal to the concentration of the products. a static condition in which the concentration of the reactants is equal to the concentration of the products. a static condition in which the rate of ...

*February 28, 2015*

**Science check **

Water in the upper zones of the ocean will have more oxygen than water in deeper zones. true or false i think true.

*February 27, 2015*

**math**

6528

*February 27, 2015*