Sunday

April 26, 2015

April 26, 2015

Total # Posts: 1,600

**Math**

Hi, I have two questions here I need help with, thank you in advance. 1. Peggy scored 68 on her first three tests of the term. What would she have to score on the fourth test to have an average of 70 on the fourth test? 2. If you were to place the digits 1,2,4,8,9, one per box...
*October 1, 2014*

**Math help!**

Thanks:)
*October 1, 2014*

**Math help!**

Identify the property of integers being illustrated in each of the following: a:(-2)(3) (the "E" letter) element of I b: (-4)0=0 c: -2(3+4)=-2(3) + (-2)4 d: (-2)3=3(-2)
*October 1, 2014*

**Math help!**

Identify the property of integers being illustrated in each of the following: a:(-2)(3) ¸ I b: (-4)0=0 c: -2(3+4)=-2(3) + (-2)4 d: (-2)3=3(-2)
*October 1, 2014*

**math**

If x is an integer and x is not equal to zero, which of the following are always positive and which are always negative? a: -x to the power of 4 b: (-x) power of 4 c: x to the power of 4 d: x e: -x
*October 1, 2014*

**AP Calc B/C**

the integration of (e^x)/(1-E^2x)^3/2 with respect to x We are currently doing integration by tables, but I can't find the formula that I should use!
*September 29, 2014*

**Physics**

A stone is tied to a string (length = 0.700 m) and whirled in a circle at the same constant speed in two different ways. First, the circle is horizontal and the string is nearly parallel to the ground. Next, the circle is vertical. In the vertical case the maximum tension in ...
*September 25, 2014*

**Physics**

A car is safely negotiating an unbanked circular turn at a speed of 18 m/s. The road is dry, and the maximum static frictional force acts on the tires. Suddenly a long wet patch in the road decreases the maximum static frictional force to one-ninth of its dry-road value. If ...
*September 25, 2014*

**Physics**

As you hurry to catch your flight at the local airport, you encounter a moving walkway that is 85 m long and has a speed of 2.2 m/s relative to the ground. If it takes you 68 s to cover 85 m when walking on the ground, how long will it take you to cover the same distance on ...
*September 23, 2014*

**chemistry**

A website promoting the use of alternative energy vehicles and hybrid technologies claims that, \"A typical automobile in the USA uses about 40 gallons of gasoline every month, producing about 750 lbs of carbon dioxide.\" To determine the truth of this statement, ...
*September 18, 2014*

**chemistry**

using your initial mass of copper, calculate the minimum volume of concentrated 12M nitric acid needed to completely react with your copper to form copper(II) nitrate? Original mass of copper was 0.40g.
*September 18, 2014*

**Math**

Calculate the dot product Ā·Ê(where Ê = Ē/E ~ is the unit vector in the direction of Ē ) and plot both Ā and Ê, showing how Ā·Ê is the projection of Ā on Ê. Ā= −4ˆi + 3ˆj Ē= 12...
*September 18, 2014*

**chemistry**

A 15.27 g sample of Mo2O3(s) is converted completely to another molybdenum oxide by adding oxygen. The new oxide has a mass of 18.33 g. Add subscripts below to correctly identify the empirical formula of the new oxide.
*September 18, 2014*

**AP Calc B/C**

Find the arc length of one arch of the sine curve. I started it by doing y=sinx, y'=cosx arc length= integral of sqrt(1+cos^2x)dx from pi/2 to 3pi/2 but I don't know how to integrate that! Thank you!
*September 13, 2014*

**Accounting - General**

Should a capital asset that is increasing in value be depreciated?
*September 4, 2014*

**Physics**

A spy in a speed boat is being chased down a river by government officials in a faster craft. Just as the officials' boat pulls up next to the spy's boat, both reach the edge of a 7.8 m waterfall. If the spy's speed is 11 m/s and the officials' speed is 22 m/s...
*September 2, 2014*

**Social Studies**

In return for offering the throne to William and Mary, it was demanded that all laws had to be approved by? A: Parliament B: King James C: The Catholic Church D: The Protestant Church My answer is A. Can someone please check if this is right?
*August 28, 2014*

**English**

I'm writing an essay. Is this semi-colon used appropriately or should it be a new sentence? At the age of six, India seemed like a completely different world to me; they had a different way of life than anything I had ever been exposed to.
*August 25, 2014*

**geography**

why is the world round, but look flat???????
*August 25, 2014*

**fitness**

They send text books for this class! I'm in the class myself, but having trouble. These are not easy classes. You have to study!
*August 16, 2014*

**AP Calc**

When a chain hangs under its own weight, its shape is catenary. The equation of a catenary with a vertex on the y-axis is y=e^x+e^-x. Find the length of the chain from x=-2 to x=2. Then use the same technique from Problem #8(Previous AP calc problem I posted) to find the ...
*July 31, 2014*

**AP Calc**

The picture to the right shows the Ben Franklin Bridge which stretches across the Delaware River joining Pennsylvania and New Jersey. The center span of the bridge is about 4200 feet long. The suspension cables hang in parabolic arcs from towers 750 feet above the surface of ...
*July 31, 2014*

**calc**

q 0 125 250 375 500 625 750 C'(q) 27 35 41 45 43 46 51 Give fixed cost = 8800 and cost of producing 250 units is 17425, how much would the total cost increase if production were increased one unit, to 251 units? --- A cup of coffee at 90 degrees celsius is put into a 30 ...
*July 21, 2014*

**math**

add 12 to both sides of the equation, and you get this: q-12+12=89+12 q=101
*July 17, 2014*

**HVAC/R**

So what they are saying is that if the ANSI standard happens to be adopted by OSHA, THEN it has the "force of law". Is that what you are reading/interpreting? And that would mean that both are correct...
*July 17, 2014*

**HVAC/R**

I know Technician B is correct, but is Technician A also correct? Is there any "force of law" carried with these standards?
*July 17, 2014*

**HVAC/R**

Oops sorry - it's either Technician A or Technician B, or Neither or Both. Who is correct? Both of them? Or Neither? Or A or B?
*July 17, 2014*

**HVAC/R**

Two technicians are discussing the HVAC/R field. Technician A says that industry codes that require certain types of installation practices carry the force of law with them. Technician B says that ANSI is an organization that establishes codes for the HVAC/R field. Which one ...
*July 17, 2014*

**statistics**

Lebron
*July 12, 2014*

**math**

Let ABCD be a cyclic quadrilateral. Let P be the intersection of \overline{AD} and \overline{BC}, and let Q be the intersection of \overline{AB} and \overline{CD}. Prove that the angle bisectors of \angle DPC and \angle AQD are perpendicular.
*July 2, 2014*

**spelling**

Hi, learning math facts and equations can definitely be difficult. Atleast I know it was for me! A great way to practice and increase the abilities of your memory are using flash-cards or playing a couple rounds of the game memory.
*July 1, 2014*

**Physics**

What is the total pressure, in atmospheres, of a 10.0 L container that contains 10 moles of nitrogen gas and 10 moles of oxygen gas at 300 K? I tried using PV=nRT and added both P together but kept getting the wrong answer. n=10, T=300 K, V=1x10^-3 m^3
*June 26, 2014*

**Geometry**

Two altitudes of a triangle have lengths 12 and 14. What is the longest possible length of the third altitude, if it is a positive integer?
*June 23, 2014*

**Chemistry**

Check my answer please? A reaction requires 22.4 L of gas at STP. You have 45.0 L of gas at 100 kPa and 373 K. Which of the following statements is true? The gas constant is 8.31 L-kPa/mol-K. You will have an excess of gas and the reaction will occur. <--------- You will ...
*June 3, 2014*

**math algebra?**

Is 1/3 , 3/4 , 0.2 in order from least to greatest or is 5 1/8 , 5 1/4 , 5 2/3 in order from least to greatest?
*June 2, 2014*

**Science**

no one goes on this site lol.
*May 28, 2014*

**physics**

Second hand = 1 rpm: 1/60 rps; i.e. 1/60 cycle/s; i.e. 1/60 Hz
*May 26, 2014*

**Physics**

Did you ask this on YA!, cuz somebody answered it 50 minutes ago just google your question and it'll come up
*May 26, 2014*

**Geometry**

mh = 40 m = (8+10)/2 = 9 9h=40 h = 40/9
*May 25, 2014*

**intro to computers**

You are shopping for a new computer. You see the memory listing as 1GBX4. What does this mean? A. 4 DDR first generation DIMMs B. 1 GB of memory made up of 4 DIMMs C. 4 GB of memory made up of 4 DIMMs D. 1 DDR fourth generation DIMMS ????
*May 24, 2014*

**intro to computers**

1.You want to purchase a new hard drive for your workstation and are deciding between an HDD and SDD drive. Which of the selections below is NOT an advantage that SDD has over HDD? A. They don’t get fragmented. B. They create less noise. C. They create less heat. D. They ...
*May 24, 2014*

**computers**

Which type of USB connector is always plugged into the computer to connect an external device? a. type A B. type B c. Micro d. Mini
*May 24, 2014*

**SCIENCE HELP !!**

In the Alps mountain range of Europe, where the huge amounts of snowpack make for a skier's dream destination, climate change has had a negative impact on the amount of snow they receive each year. Due to warmer temperatures caused by a steady increase in temperature in ...
*May 22, 2014*

**Calc**

A patient receives a 3 ml dose of medicine. The amount, y, of medicine in the body decreases at a rate of 15% per hour (dy/dt=-.15y). When the medicine in the patient is down to 1 ml, the nurse administers a second 3 ml dose and plans to give the patient a third dose when the ...
*May 11, 2014*

**Calculus**

For the parabola y^2=4px, where p, the focal length, is a constant, the focal point, f(p,0), is on the x-axis. Point S is 10 units from the point F and the segment SF makes a 60degree angle with the x-axis. The slope of segment TF is twice the negative of the slope of the ...
*May 11, 2014*

**chemistry**

The oxygen from the air could cause the hydrogen to ignite.
*May 9, 2014*

**math**

ms. sue that is a link to a different question
*May 7, 2014*

**science PLEASE CHECK MY ANSWERS**

1. C 2. B 3. A 4. B
*May 7, 2014*

**science**

Thank you Amy.
*May 6, 2014*

**CALCULUS**

The region R is bounded by the x-axis, y-axis, x = 3 and y = 1/(sqrt(x+1)) A. Find the area of region R. B. Find the volume of the solid formed when the region R is revolved about the x-axis. C. The solid formed in part B is divided into two solids of equal volume by a plane ...
*April 29, 2014*

**CALCULUS HELP PLZ**

The region R is bounded by the x-axis, y-axis, x = 3 and y = 1/(sqrt(x+1)) A. Find the area of region R. B. Find the volume of the solid formed when the region R is revolved about the x-axis. C. The solid formed in part B is divided into two solids of equal volume by a plane ...
*April 29, 2014*

**statistics**

Some students were asked, "Would you date someone with a great personality even though you did not find that person to be attractive?" Of the 131 women surveyed, 61.1% said yes, and of the 61 men surveyed, 42.6% said yes. Is there sufficient evidence to conclude that...
*April 26, 2014*

**statistics**

A researcher believe that college students spend a different amount of time talking on the phone than they do instant messaging. She takes a random sample of 12 college students and records the number of hours per week each student spends on each activity and plans to test at ...
*April 26, 2014*

**Maths**

Cheater! I am doing the maths challenge too and this isn't fair to the other students.
*April 26, 2014*

**science**

I took this, and the answers are: 1. B 2. A 3. C 3. C
*April 24, 2014*

**math, calculus**

1. Consider the region bounded by the curves y=|x^2+x-12|, x=-5, and x=5 and the x-axis. A. Set up a sum of integrals, not containing an absolute value symbol, that can be used to find the area of this region. B. Find the area of the region by using your answer from part A. ...
*April 23, 2014*

**Probability**

re: E[X^2]: Remember that Var[X] = E[X^2]-(E[X])^2 and also that (in short-hand) Var[X] = E[Var] + Var[E]. Use this last identity to get Var[X]; we already have E[X] so we can easily get E[X^2].
*April 20, 2014*

**Probability**

Because the variance of the sum of two RV's is only equal to the sum of the variances if the two RV's are independent. If the two RV's are dependent then the variance of the sum of the two RV's = sum of the variances + 2*COV(the two RV's)
*April 20, 2014*

**Math**

We are learning about proofs. We drew lines between noncollinear points. Our table showed 2 points >> 1 line segment, 3 point >> 3 line segments, 4 points >> 6 line segments, 5 points >> 10 line seg, 6 points >> 15 line seg. etc. Write an ...
*April 12, 2014*

**Physics (Rotation)**

In the figure, wheel A of radius rA is coupled by belt B to wheel C of radius rC. The angular speed of wheel A is increased from rest at a constant rate α. Find the time needed for wheel C to reach angular speed ω assuming the belt does not slip. (Hint: If the belt ...
*April 12, 2014*

**Science/Biology**

Please check my answers: 1. Which of the following correctly states the relationship between monkeys and humans? A. Humans and monkeys evolved from apes. B. Humans evolved from monkeys. C. Humans and monkeys evolved from the same ancestor, which is now extinct. D. Humans ...
*April 4, 2014*

**English**

List as many details as you can for each of the topic sentences. 1. Walking briskly for a mile after a day sitting at a desk helps dispel fatigue. Purpose: To explain 2.Bird watching in the woods is relaxing as well as educational Purpose: To convince
*April 3, 2014*

**Science**

anyone at all?
*April 3, 2014*

**Science**

please help me
*April 3, 2014*

**Science **

fill in the blank questions monotremes, marsupials, and placentals have the same _____ known as the therapsid. a farmer sprays insecticide on his crops and notices that the insect pest problems disappear. a year later he tries the same insecticide only to find that he did not ...
*April 3, 2014*

**calculus and vectors**

Determine an equation of the line of intersection of the planes 4x − 3y − z = 1 and 2x + 4y + z = 5.
*April 1, 2014*

**science**

Thanks Amy! THOSE ARE CORRECT.
*March 31, 2014*

**science**

I would like to share my answers for the fill in the blanks. These ARE NOT proven to be correct, but I think most are good and most likely correct answers. Hopefully, you find them helpful. 14. Chemical 15. Heterogenous 16. Density 17. Chem Form 18. Temperature 19. Pressure 20...
*March 31, 2014*

**Math**

Use the following four coordinates to determine which one has a distance of 10 units from point C (1, 2). (3, 4) (7, 1O) (6, 7) (8, 9)
*March 26, 2014*

**Economics HELP PLEASE!!!!**

Yes how about this one? Suppose that firms are NOT owned by consumers. Let s denote the size of the per-unit subsidy/tax given to the firms. Let positive values of s denote subsidies, and negative values of s denote taxes. QUESTION: What is the value of s that maximizes total ...
*March 21, 2014*

**AP Calc**

The base of a solid is bounded by y=|x|+a, <a<, and the line y=3. Find, in Cu. units in terms of a, the volume of the solid if every cross section perpendicular to the y-axis is an equilateral triangle.
*March 18, 2014*

**AP Calc**

If x=e^t and y=t^2-3, then for what values of t, t>=0, is the function y=f(x) concave up?
*March 17, 2014*

**AP Calc**

The coordinates of the point on the curve cos(y)=x-y, -pi<=x<=pi, where the tangent line to the curve is a vertical line is ____.
*March 17, 2014*

**AP Calc**

The base of a solid is the region in the first quadrant bounded by the ellipse x^2/a^2 + y^2/b^2 = 1. Each cross-section perpendicular to the x-axis is an isosceles right triangle with the hypotenuse as the base. Find the volume of the solid in terms of a and b. I'm having...
*March 17, 2014*

**AP Calculus**

Approximating the integral from 0 to 6 of (e^x dx) by 3 circumscribed rectangles of equal width on the x-axis yields ____. a) 2e^2 + 4e^4 + 6e^6 b) 2(e^2 + e^4 + e^6) c) 2(e + e^3 + e^5) d) e + 3e^3 + 5e^5 e) e^2 + 3e^4 + 5e^6
*March 17, 2014*

**Math**

idiots
*March 17, 2014*

**AP Calculus**

The average area of all squares with sides between a inches and b inches (b>a) is ____ in^2.
*March 16, 2014*

**AP Calculus**

The base of a solid is bounded by y =|x|+a, 0<a<3, and the line y=3. find in cu. units in terms of a, the volume of the solid if every cross section perpendicular to the y-axis is an equilateral triangle.
*March 16, 2014*

**CALCULUS ECONOMICS**

??
*March 13, 2014*

**Science 6th grade Earth's day and night ANSWERS**

The answers are correct.
*March 12, 2014*

**science**

An atom of sodium-23 (atomic number = 11) has a positive charge of +1. Given this information, how many electrons does it have? How many protons and neutrons does this atom have?
*March 9, 2014*

**science**

A hydrogen atom has one proton, two neutrons, and no electrons. Is this atom an ion?
*March 9, 2014*

**Probability**

Anyone know answer to 2?
*March 7, 2014*

**Geometry **

In baseball, the length of the path between each pair of consecutive bases is 90 feet. The paths form right angles. How far does the ball need to travel if it is thrown from home plate directly to second base? A. 90 feet B. 127.3 feet C. 135.7 feet D. 180 feet
*March 6, 2014*

**MATH**

I agree with tbetzz
*March 5, 2014*

**MATH**

But why would you subtract the 576 and 144. and plus to find the circumference you were supposed to times the 576 by pi and the 144 by pi
*March 5, 2014*

**Physics**

its 54.7 km/s
*March 4, 2014*

**Geometry **

A trapezoid has a perimeter of 14 feet. What will the perimeter be if each side length is increased by a factor 7? A. 21 feet B. 98 feet C. 196 feet D. 686 feet This one is def B correct?
*March 2, 2014*

**Geometry **

A rectangle has an area of 6 square meters. What will be the area of the rectangle if each side length is increased by a factor 5? A. 11 square meters B. 30 square meters C. 125 square meters D. 150 square meters I think the answer is B
*March 2, 2014*

**Geometry**

Is it D?
*March 2, 2014*

**Geometry **

A rectangular prism has a base that is 5 cm by 7 cm and a height of 12 cm. If all dimensions are doubled, what happens to the volume? A. When the dimensions are doubled, the volume is twice the original volume. B. When the dimensions are doubled, the volume is three times the ...
*March 2, 2014*

**Geometry **

A triangle is enlarged by a factor of 3. The perimeter of the new triangle is 36 feet. What could be the lengths of the sides of the original triangle? A. 3 feet, 4 feet, and 5 feet B. 1.5 feet, 1.25 foot, and 1.25 foot C. 2 feet, 0.5 feet, and 1.8 feet D. 4 feet, 4 feet, and ...
*March 2, 2014*

**Geometry **

The circumference of a circle changes from 20 to 4 after a dilation. What was the scale factor of the dilation? A. 1/25 B. 1/5 C. 5 D. 25
*March 2, 2014*

**Geometry **

A circle with a radius of 1/2 ft is dilated by a scale factor of 8. Which statements about the new circle are true? Check all that apply. A.The length of the new radius will be 4 feet. B.The length of the new radius will be 32 feet. C.The new circumference will be 8 times the ...
*March 2, 2014*

**Geometry **

What is the height of a cylinder with a volume of 384π cubic inches and a radius of 8 inches? Round to the nearest tenth of an inch.
*February 28, 2014*

**Geometry **

A cylindrical water tank has a diameter of 20 feet and a height of 15 feet. How much water is needed to fill the tank?
*February 28, 2014*

**math- calculus**

You will often see proj (Vector a onto Vector b) written as projb⃗ a⃗ .Show that projb⃗ a⃗ =(a⃗ ⋅b⃗/ b⃗ ⋅b⃗ )*b⃗ .
*February 26, 2014*

**physics**

(a) A car with a mass of 950 kg is moving to the right with a constant speed of 1.45 m/s. What is the total force on the car? (b) What is the total force on the car if it is moving to the left?
*February 21, 2014*

**math**

A stairway runs up the edge of the pyramid. From bottom to top the stairway is 92 m long. The stairway makes an angle of 70° to the base edge, as shown. A line from the middle of one of the base edges to the top of the pyramid makes an angle of elevation of 52° with ...
*February 20, 2014*

**Black Death**

I have to do a powerpoint on the Black Death. Where can I find the best information to write about it?
*February 19, 2014*