Posts by alan

Total # Posts: 383

Physics, Calculus
if an aircraft flying at 250km/h at bearing N 45East for 1 hour meets a wind from the NW at 50km/h, then how long will it take to fly the full 550km maintaining its N45E bearing to the ground with this wind blowing?

Math
There are 36 books on a bookcase.there are 9 nonfiction,12 fiction,and 15 science fiction. What is the probability of choosing a nonfiction book of choosing a fiction book of choosing a science fiction book?

Math
2 2/4 divide by 1 1/4

Physics
I will assume this is on Earth, with an acceleration due to gravity of 9.8 m/s/s. Force = mass * acceleration. A 50 kg mass therefore weighs 50 * 9.8 = 490 Newtons, which is the force required to lift the object. The energy required is force times distance, or 490 * 0.2 meters...

science
Steve's calculation is correct. It is worth noting that if you had an actual 1 gram block of Radium-226, its mass would NOT be reduced all the way to 0.9 grams after 241.7 years. Radium-226 decays by alpha emission to Radon-222, which goes quickly through a sequence of ...

chemistry
i literally have no idea how to do these and your explanations are not helping..... like i have no example and i need you to work one out and i can do the other but they are do soon and i have no clue what you are saying.

chemistry
A 8.408 gram sample of an organic compound containing C, H and O is analyzed by combustion analysis and 12.53 grams of CO2 and 3.849 grams of H2O are produced. In a separate experiment, the molar mass is found to be 118.1 g/mol. Determine the empirical formula and the ...

chem
for molecular i got 1 and 1 empirical i don't know what to do

chem
this completely confused me.... these are bonus problems we have not been taught for extra credit and i can't figure out the answers

Chemistry
What is the Net Ionic Equation for Nitric Acid and Potassium Carbonate?

Chemistry
What is the concentration in each of the following solutions? A) 240 mL of 0.200 M KNO3 is added to 160 mL of water. B) 2.25g of NaCl is dissolved in 250 ml of water.

Chemistry
The quantity of Cl- in a water supply is determined by titrating the sample with Ag+. What mass of chloride ion is present in a 10,0g sample of the water if 20.2 ml of 0.100 M Ag+ is required to react with all the chloride in the sample?

Chemistry
7. A student conducts an experiment on a different hydrate. The empty crucible is heated to a constant mass of 24.330. A sample of the unidentified hydrate is placed in the crucible, and the total mass is 31.571 g. The crucible and hydrate are heated to constant mass, which is...

maths
Gunpowder contains 75%nitre and10% sulphur.find the amount of gunpowder which carries 9 kg nitre . what amount of gunpowder would contain 2.5kg sulphur

Maths
-3x+2y=-6

physics
what is the maximum torque on a rectangular coil 5 cm x 12 cm and with 600 turns when carrying a current of 0.0700A in a uniform field with magnitude 0.300T?

Chemistry
5 grams of H2 reacts with 16 g of O2, which in excess? 2H2(g)+O2(g)=2H2O(g)

math
If the store purchases an item at a wholesale cost of \$3.50 per item, and it is sold at a retail value of \$5.00 per item. What is the gross profit percentage of the item?

Geometry
A wheel 2ft wide rolls a distance of .015 miles in .005 hours. What is the wheels speed in rpm's?

Geometry
The diagonals of rectangle ABCD intersect at point E. If AE=2x+5, and BD=5x+2, what is AC?

Chemistry
Nicotine is a basic substance and its dissociation constant is about 1.0 x 10-6. To prepare a solution water with 0.01 mol L-1, calculate the PH

Chemistry
An amount of 25ml of a 0.8 Molar solution of pure KNO3 and placed in a volumetric flask. Is added water until the thin volume reaches exactly 500ml. which the final concentration?

Chemistry
An aluminum sheet used for food preservation weighs about 0.05 g/cm-2 How many electrons are in a 1 cm2 of this sheet?

algebra
[Question] Can someone please argue with me against 'decreased' being a past-tense word? My interpretation: 3(x - 7) = x + 39. Please EXPLAIN why this is not the case even though it was worded this way. Thank you

Math help Steve?
Oh never mind! So the answer would be B?

Math help Steve?
1) Given that p(-3), p(-1), and p(5)=0, which expression could be p(x)? A)x^3-x^2-17x-15 B)x^3+x^2-17x+15 C)x^3-3x^2-13x+15 D)x^3-9x^2+23x-15 Hi Steve, I got what you said, but how would I solve this equation then?

Math
Hello again! I would appreciate help very much on this. Thank you! 1) For which values of x is y equal to 16 in the equation y=|3x+4|? A) -60 and 36 B) -36 and 60 C) -20/3 and 4 D) 20/3 and 4

Math
Oh ok, I understand that. Thank you so much!

Math
1. Which function represents an initial population that increases 22% per year where A represents the initial value and X represents time in years? A. Y=A(0.22)^x B. Y=A(0.68)^x C. Y=A(1.22)^x D. Y=A(1.68)^x I do not get how to solve this problem. Any help would be great. ...

Math
Thank you so much!

Math
Any help would mean so much to me. Thank you!

Math
1) Malene rented a compact car for 10 days and drove it 620 miles for a total cost of 412\$. Patrick rented a compact car at the same rental car company for 6 days and drove it 850 miles. His total cost was 295. Which system of equations could be used to determind d, the charge...

1) Given that p(-3), p(-1), and p(5)=0, which expression could be p(x)? A)x^3-x^2-17x-15 B)x^3+x^2-17x+15 C)x^3-3x^2-13x+15** D)x^3-9x^2+23x-15 2) Coaches in a football conference had the option to vote for or against a rule change. The table below shows the results. 4 people ...

Math
1)If the roots of a quadratic equation are -2 and 3, the equation can be written as A) (x+2)(x+3) B) (x-2)(x+3)** C) (x+2)(x-2) D) (x-2)(x-3) Is the answer B? If someone could help me that would be great.

Physics
A constant retarding torque of 12 N*m stops a rolling 0.80 m diameter wheel in a distance of 15 m. How much work does the torque do?

Physics
Determine the acceleration of each object, including its direction. Determine the tensions in the two cords.

Physics
Three blocks are connected on the table as shown below. The coefficient of kinetic friction between the block of mass m2 and the table is 0.345. The objects have masses of m1 = 3.25 kg, m2 = 1.25 kg, and m3 = 2.50 kg, and the pulleys are frictionless. The Photo: w w w(dot)...

algebra
Mary wants to hang a mirror in her room. The mirror and frame must have an area of 7 square feet. The mirror is 2 feet wide and 3 feet long. Which quadratic equation can be used to determine the thickness of the frame, x? (4 points)

math

Physics
The resonator of a string instrument is commonly an oddly shaped box or a wide thin board. The resonator is not sharply tuned; it responds to broad bands of frequencies and radiates sound at those frequencies from its entire surface area. The response of the body or soundboard...

History
Was the only change in science in quantum physics and relativity? I know it changed the way people thought about the predictability of human nature during the enlightenment and the 1st scientific revolution, but how did this contribute to the age of anxiety? I don't ...

History
I have to write a 150-200 word essay on it

History
What were the major changes in sciences view of the nature of the universe and humanity's place in it between 1850 and 1914? How did these developments contribute to the age of anxiety? How are these changes reflected in philosophy, psychoanalysis, and artistic style ...

AP Calc
Wait don't you plus x=14 back in to y=(84-4x)? Cause y then equals 20 in

AP Calc
The US Post Office has a limit on the size of packages it will accept for mailing. The length plus the girth must be 84 inches or less. Find the dimensions of the rectangular package with a square end, which will maximize the volume of the package.

MATH
Mimi's Market sold 24 heads of lettuce one morning. That afternoon 2/7 of the remaining heads of lettuce were sold. The number of heads left was now 1/2 of the number the market had at the beginning of the day. How many heads of lettuce were there at the beginning of the day?

math/set theory
120 quilts were entered into a quilt show. (Traditionally, all quilts were hand stitched but now many are stitched on machines. Appliques are additional pieces of cloth that are sewn on top of the quilt.) In this show, 86 were machine stitched. 44 had appliques applied. 24 ...

Social Studies
What are some lifestyles for the following countries: -Kazakhstan -Kyrgyzstan -Latvia -Liechtenstein

Physics
A ball rolling with initial velocity of 40m/s(W) undergoes an acceleration of 5.0m/s^2(N) for a period of 6.0seconds. (A) what is the final velocity of the ball? (B) what is the displacement of the ball in the 6.0 sec

Physics
A ball rolling with initial velocity of 40m/s(W) undergoes an acceleration of 5.0m/s^2(N) for a period of 6.0seconds. (A) what is the final velocity of the ball? (B) what is the displacement of the ball in the 6.0 sec

Maths
Mathew is attending a very loud concert by the discarded. To avoid permanent ear damage he decides to move farther from the stage. Sound intensity is given by the formula I=k/d*d where k is the constant and d is the distance in metres from the listener to the source of the ...

math
Fred has 15 cows John has twice as many cows as Fred had when Fred had as many cows as John has now how many cows has John?

Organic Chemistry
What ketone or aldehyde would be reduced to produce each alcohol, respectively: a. 3,3-Dimethyl butan-2-ol b. 3-Methyl butan-1-ol c. Benzyl alcohol

Biology - Help!!
2 and 5 are wrong for anyone who may use this to answer their test

ch
A 0.160-g sample of unknown metal (X) reacts with hydrochloric acid to produce 66.5 mL? Help please

Math
Evaluate the expression for the given value. x = 3; y = -5; z = -2 x(yz)^2 - 3(xyz)^0 + 2x^2yz^2 = 3(-5 * -2)^2 - 3(3 * -5 * -2)^0 + 2(3)^2(-5 * -2)^2 = 3 * 100 - 3 * 30 + 2 * 9 300 - 90 + 18 = 228

-2(-2)^2 * 3 - 3(-2)(3)^2 * -1 - (-2)(-1) -2 * -4 * 3 - 3(-2) * 9 * -1 (-2)(-1) -2 * -4 * 3 - 6 * 9 * -1 * 2 24 - 108 = -84

Math
Evaluate the expression for the given value. x = -2; y = 3; z = -1 -2x^2y - 3xy^2z - xz =

Chemistry
In a double-stranded DNA molecule, the percentage of Guanine can never be more than ___%. Why?

Chemistry
Which of the following statements must be True? Check all that apply. The number of Adenines in single-stranded DNA equals the number of Thymines. The number of Guanines in single-stranded DNA equals the number of Adenines. The number of Thymines in double-stranded DNA equals ...

Math
Solve the following: -6x + 3 <= 25

Math
Solve the following. 2(x + 1) - 4 <= 1/4(12x - 24)

Math
Evaluate when x = 2, y = -5, z = 3. x^2 - y = 3 3z - 4(y + 1) - y^2 = 0 x - yz = -13

Math
Simplify or solve as appropriate. Enter ns if there's no solution or all if the solution is all real numbers. 2 - 3(x + 5)) = 10 X = -7.6 7z + 6 - 2(z + 3) 5 * z 1/2x - 5 = 3/4x + 7 X = -48

Math
Using the linear equation y = -3x + 5, complete the table of values (T-Chart) and choose the correct graph. X = -2 Y = _ X = -1 Y = _ X = 0 Y = _ X = 1 Y = _ X = 2 Y = _

Math
Using the linear equation y = 5, answer each of the following. Choose all points that would be on this line. (0,5), (5,5), (2,5), (5,2), (-3,5), or (5,-3)

Math
Find the x-intercept and the y-intercept of the linear equation 3x + 4y = 12. Write each intercept as an ordered pair.

Please check if these math questions are correct
8 = p - 5 Answer: p = 13 21 + y = 35 Answer: y = 14 6x = 54 Answer: x = 9

Math
Solve -4x is less then equal to -16. I got x is less then equal to 4. Is this correct I'm kind of confused with this question.

Math
Solve for X. X/8 = -4/9

Math
Evaluate the following expressions when x = -2, y = 6, and z = -4 y^2 + 3z 5y - 3(x^2 + 1) + z

Math
When driving to the beach, you drive 240 miles on 9 gallons of gas. When you arrive at the beach you fill up your gas tank. While there you drive 130 miles and use 5.8 gallons of gas. Round answers to 2 decimal places. What was your gas mileage driving to the beach? What was ...

Math
Choose True or False for each of the following. 87% is equivalent to 0.87 True or False 1.29 is equivalent to 129% True or False 0.5% is equivalent t0 0.05 True or False 5.6 is equivalent to 56% True or False

Math
Convert each of the following. Round your answer to two decimal places if necessary. 0.68 miles = 43084.80 inches 10259 feet = 3419 yards

Math
If a boat travels at 5 miles per hour, how many feet per second does it travel? Round your answer to two decimal places if necessary. 26400 feet per second

Math
Three friends go to their favorite seafood restaurant for dinner. They decide to order a crab cake appetizer. When it arrives there are only 2 crab cakes. What fraction of a crab cake will each friend get to eat? 3/2 Write the fraction as a decimal rounded to 2 decimal places...

Math
Your favorite chocolate chip cookie recipe makes 4 dozen cookies. Among the other ingredients, the recipe calls for > 1 cup of butter > 2 tsp vanilla extract > 3 cups of flour > 1/2 tsp salt You are asked to make 6 dozen cookies for a party. How much butter, ...

Math
Perform the indicated operation and simplify. 1. 1/4 + 1/3 = 2/3 2. 4/7 - 5/6 = 1/6 3. 3/5 * -4/7 = -12/35 4. 10/11 divided by 2/3 = 15/11

Math
Is 10.512 * 10^3 written in proper scientific notation? If not rewrite the number in proper scientific notation.

Math
You have a table in your living room with a round top that has a diameter of 2 1/2 feet. You would like to put a piece of glass over the top of the table to protect the surface. What is the area of the table top? (Use 3.14 for the value of pi). Write your answer as a mixed ...

Math
You pull into a gas station where the sign says the gas costs \$3.679. To fill up your tank you need 20 1/2 gallons of gas. You plan to use your credit card to pay. Rounded to the nearest cent, what will the charge be on your credit card? \$75

Math
Perform the indicated operation. Write your answer as a simplified fraction. 1. 1/3 + 0.25 = 7/12 2. 0.3125 - 1/4 = 1/16 3. -7/10 + 0.2 = -9/10

Math
Convert the following decimals to a simplified mixed number. 1. 0.33 = 1/3 2. 1.875 = 1 7/8

Math
You and your friend ordered a 12 inch pizza to split for lunch. How many square inches of pizza do you each get to eat? Round answer to 2 decimal places. 37.68 square inches

Math
You live 35 1/3 miles from your grandmother's house. You're workplace is 7 2/5 miles from your grandmother's house. If you drive by your grandmother's home on the way to work one morning, what is the total number of miles you drove that morning? Write your ...

Math
Multiply each of the following. Write your answer as a simplified fraction. 1. 4/7 * 5 = 20/7 2. 15/28 * 7/9 = 105/252 3. -3 1/5 * 7/8 = -56/20

Math
Add each of the following. Write answer as a simplified improper fraction. 1. 3/25 + 8/35 = 61/175 2. 5 1/4 + 3 5/12 = 26/3 3. -4 1/2 + 2 2/3 = -19/6

Math
-3 7/16 = -41/16 = -2.56 25/13 = 1.92

Math
Convert the following fractions to decimals. Round to 2 decimal places if necessary. 1. 1/4 2. -3 7/16 3. 25/13

Math
Simplify each of the following. 1. 42/48 2. -15/35 3. 119/210

Math
Write as an improper fraction. 1. 7 3/5 2. -12 1/2 3. 41 4/6

Math
Write as a mixed number. 1. 13/11 2. -33/6

Math
My son doesn't how to do 15+37

Algebra
I think it 32

Physics
186

What series of events led to the end of Egypts power in the Nile River Valley?

History

chemistry
How many moles of H2O are needed to react with 15.0g of CaO forming Ca (OH)2? CaO + H2O --> Ca (OH)2