# Posts by peter

Total # Posts: 1,014

**Pre-Calculus**

If θ represents an angle such that sin2θ = tanθ - cos2θ, then sin θ - cosθ = A. -√2 B. 0 C. 1 D. 2√2 What equation can I use to solve this problem?

*July 31, 2012*

**math**

174

*June 24, 2012*

**Physics**

A gas is sealed in a container with rigid walls that allow heat to flow through them. A thermal process takes place on the gas. What would be the best model for the type of process?

*June 21, 2012*

**chemistry**

how many gram of NaNO3 are in 25cm3 of 0.01m NaNO3 solution?

*June 11, 2012*

**Physics**

A large air-filled 0.1-kg plastic ball is thrown up into the air with an initial speed of 16 m/s. At a height of 4.7 m, the ball's speed is 5 m/s. What fraction of its original energy has been lost to air friction? (Note that the initial height is taken to be zero.)

*June 1, 2012*

**statistics**

„« If the city spends $145,000 on promotional expenditures. What will be the projected attendance at 95% confidence level?

*June 1, 2012*

**science**

Please help. Concentrated hydrochloric acid is a 38% w/w solution of HCL in water and has a density of 1.18g/ml. How many millilitres of concentrated hydrochloric acid are needed to prepare 500ml of a 1:200 w/v HCL solution? My answer is 2.12ml. I'm not sure if its correct...

*May 9, 2012*

**chemistry**

1:200 w/v means 1g in 200ml

*May 7, 2012*

**chemistry**

Please help. Concentrated hydrochloric acid is a 38% w/w solution of HCL in water and has a density of 1.18g/ml. How many millilitres of concentrated hydrochloric acid are needed to prepare 500ml of a 1:200 w/v HCL solution? My answer is 2.12ml. I'm not sure if its correct...

*May 7, 2012*

**math**

(x-16)^2=64

*April 30, 2012*

**life orintation**

identify and describe one environmental problem that causes ill health,crises,accidents,and disasters within your community or any other community within south africa or globally

*April 27, 2012*

**East Asia,and south easia**

A. Both Cambodia and Vietnam carried out ethnic eradication programs against hill people. B. The Khmer Rouge leaders have never been brought to trial. C. The leaders of the Khmer Rouge fled from Cambodia after 1979. D. Chinese merchants living in Cambodia and elsewhere have ...

*April 22, 2012*

**L.o**

Limpopo

*April 22, 2012*

**Organic Chem**

Outline a separation scheme for isolating pure isopentyl acetate from the reaction mixture.

*April 16, 2012*

**physics**

A spring whose spring constant is 650 N/m is compressed 0.300 m. What speed (in meters/second) can it give to a 0.300 kg ball when released

*April 11, 2012*

**Math(Algebra)**

Determine whether the pair of lines are parallel, perpendicular, or neither. 1)f(x)=2/3x+1 2)2y+3x=1

*April 1, 2012*

**chemistry**

I don/t know

*March 21, 2012*

**Geometry**

Sorry Steve, you made a major error with your units... the radius of the Earth is around 6378 km not 6378 miles. You are trying to find the distance from the Space Station to the horizon, which would be the point of tangency. The tangent line from the Space Station will form a...

*March 19, 2012*

**calculus**

At a quarry, sand is filling off a conveyor onto a conical pile at a rate of 15 cubic feet per minute. The diameter of the base of the cone is four times the height. At what rate is the height of the pile changing when the pile is 12 feet high?

*March 15, 2012*

**Further maths**

Y=x^3-6x^2+9x-4.calculate the average rate of change of y with respect to x.

*March 14, 2012*

**math**

What inverse operation is needed for the first step in solving the equation 12+5x=22? a. addition b. subtraction c> multiplication d. division

*March 11, 2012*

**math**

Xenia wants to stuff a cube-shaped footstool that measures 10.25 inches on all edges. What is a good estimate of the number of cubic inches of foam peanuts that she will need? a. just over 1,331 cubic inches b. just over 1,000 cubic inches c. just over 30 cubic inches d. just ...

*March 11, 2012*

**calculus**

A tank consists of a right circular cylinder at height (h)surmounted by a hemisphere at a radius (r) with an outlet atthe top. The tank is full of water at density ρkg/m3. Find the work required to empty thetank.

*March 10, 2012*

**math**

A recipe for one large cake calls for 3 2/3 cups of flour. Anya has decided to increase each ingredient in the recipe by 2 1/2. How many cups of flour does she need?

*March 8, 2012*

**Social 30-1**

that site doesnt work for me

*March 6, 2012*

**Social 30-1**

hello i am doing a recearch project on Hong Kong and one of the questions are: what are your countries Fiscal and monentary policies? i cant find them anywhere. if i could get your help that would be great!

*March 6, 2012*

**Biology**

I'm confused on the rule of multiplication and the rule of addition. When do I use each to determine the probability of a genetic trait being inherited.

*March 4, 2012*

**maths**

Like simultaneous equations? p + 18 + q = 1/8p - 4.5 +q I get -25.71..... Is this right?

*March 3, 2012*

**maths**

f(x)=px^3 + 6x^2 + 12x + q given that the remainder when f(x) is divided by (x - 1) is equal to the remainder when f(x) is divided by (2x + 1), (a) find the value of p. given also that q = 3, and p has the value found in part (a) (b) find the value of the remainder. my working...

*March 3, 2012*

**Biology**

The observed distribution of offspring was: black-red 1,070; black-white 177; green-red 180; green-white 1,072. Based on these data, what is the recombination frequency? A. 86% B. 7% C. 17% D. 14% E. 30% Background Info: In a particular species of mammal, black hair (B) is ...

*March 2, 2012*

**Biology**

Jessica has no dimples and attached ear lobes. Jessica's mother has dimples and detached ear lobes, and her father has no dimples and attached ear lobes. Assuming independent assortment, what are the chances that her new baby brother will have dimples and attached ear lobes?

*February 29, 2012*

**cch**

a bridge over a river is loaded at three penal points. determine the support reactions at a and b

*February 21, 2012*

**Algebra 2**

Solve each equation below for x. (Use logarithms.) 10^(2x^(2)-5x+11) = 10000 9^(2(x-1)) = √(27)

*February 19, 2012*

**Algebra 2 Decay**

You have 20 grams of phosphorus-32 that decays 5% per day. How long will it take for hlaf of the original amount to decay?

*February 17, 2012*

**Inequalities**

Budgets her monthly take-home. The remainder she deposits in her savings account. she budgets 1/3 rent. 1/8 for car 1/6 food, 1/24 insurance. and 1/16 for entertainment, What is her monthly take-home pay if she deposits $546.00 in her savings account?

*February 15, 2012*

**Social 30-1**

im not asking them to write the assignment. just want some ideas. i have to write an essay and im not expecting people to do that.

*February 11, 2012*

**Social 30-1**

Who benefited from the growth of classical liberalism during the industrial revolution? Who did not benifit from it? Why didn't the theorys of classic liberalism extend to all classes and people?

*February 11, 2012*

**economics**

Suppose that there are three beachfront parcels of land available for sale in Asilomar and six people who would each like to purchase one parcel. Assume that the parcels are essentially identical and that the minimum selling price of each is $600,000. The table below reflects ...

*February 10, 2012*

**Social 30-1**

Who benefited from the growth of classical liberalism during the industrial revolution? Who did not benifit from it? Why didn't the theorys of classic liberalism extend to all classes and people? please help

*February 8, 2012*

**math**

Drew was leveling a table. One corner had to be raised 3/4 inch. He had some pieces of wood 1/16 inch thick. How many pieces of wood would he need to use for the corner to make the table level?

*February 1, 2012*

**math**

The temperature outside rose 41 degrees during a 12 hour period. If the temperature rose the same number of degrees every hour, what is a good estimate of the number of degrees the temperature rose each hour?

*February 1, 2012*

**Biochemistry**

Thanks Doc!

*January 29, 2012*

**Biochemistry**

1. MES (2-(N-Morpholino)ethanesulfonic acid) is a common buffer used in biochemistry labs to stabilize proteins. The pKa for MES is 6.09. a. What is the pH of 1 liter of a 200 mM MES aqueous solution? Clue: you will need to solve a quadratic equation. (2.5 points) b. How much...

*January 29, 2012*

**Maths**

In how many places does y=4x^2-2x-5 cross the x axis?

*January 25, 2012*

**math**

Clara's pay from her paper route is based on the expression $15 + $0.10p, where p is the number of papers she delivers during the wiik. What would her weekly pay be if she deliver 315 papers each week?

*January 25, 2012*

**Math**

My son is grade 4 his homework have question is : when you multiply any number by 1,what is the product ? Please help !!!!

*January 23, 2012*

**Math**

when you multiply any number by 1,what is the product ?

*January 23, 2012*

**Maths**

solve 3^x=4^(x-2)

*January 20, 2012*

**Algebra 2**

An orange grower finds that she gets an average yield of 40 bushels per tree when she plants 20 trees on an acre of ground. Each time she adds a tree to an acre, the yield per tree decreases by 1 bushel, due to congestion. How many trees per acre should she plant for maximum ...

*January 18, 2012*

**Algebra 2**

What is the maximum product of two numbers whose sum is 22? What numbers yield this product?

*January 18, 2012*

**Algebra 2**

A rancher is fencing off a rectangular area with a fixed perimeter of 76 m. What dimensions would yield the maximum area? Find the maximum area.

*January 18, 2012*

**Algebra 2**

Consider a circle centered at (2,4). What are the coordinates of the center of the translated circle if we replace x with x-3 and y with y+5 in the equation of the circle?

*January 15, 2012*

**math**

Give each letter of the alphabet a money value: A= 1 penny, B= 2 penny, C= 3 penny,and so on.Find words worth 1/5 dollar, 9/10 dollar, 1 1/20 dollars, and 1 1/2 dollars.

*January 15, 2012*

**math**

Give each letter of the alphabet a money value: A=1c, B=2c, C=3c,and so on.Find words worth 1/5 dollar, 9/10 dollar, 1 1/20 dollars, and 1 1/2 dollars.

*January 15, 2012*

**Algebra 2**

Find the equation of the parabola that goes through the given points. (1,2) (0,5) (-1,14)

*January 14, 2012*

**Algebra 2**

The perimeter of a rectangle RSTV is 44 ft. Find the least value of the diagonal RT.

*January 14, 2012*

**math**

A soccer game started at 11:10 a.m. and lasted 1 1/2 hours. About what time did the game end? (A) 12:30p.m. (B) 1:30p.m. (C) 12:00a.m. (D) 1:00a.m.

*December 21, 2011*

**math**

Find digits A and B in the number below so the folling condition are true. The 5-digit number must be divisible by 4. The 5-digit number must be divisible by 9. Digit A cannot be the same as Digit B. 12A3B Explain the steps you followed to solve the problem.

*December 21, 2011*

**Math 30 pure**

why thank you!

*December 20, 2011*

**Math 30 pure**

simplify: (x+y)^10 simplify: (2a+5)^5

*December 20, 2011*

**English**

what are 4 main disadvantages of visiting other countries?

*December 17, 2011*

**Biology**

I go with B. It makes more sense that way. DNA never leaves a cell only messenger RNA does.

*December 11, 2011*

**math**

suppose you deposited $3000 of earned income into an IRA, you can earn an annual interest rate of 8%and you are in a 40% tax bracket (Note:interest rates and tax brackets are subject to change over time, but some assumptions must be made to evaluate the investment) Also, ...

*December 11, 2011*

**maths**

find the distance in kilometers traveled by an areoplane moving at 150km/h for 50minutes.

*December 11, 2011*

**english**

Thank you Writeacher.

*December 10, 2011*

**english**

I have to find three or four nouns, adjectives, adverbs and verbs from a book. Please can you tell me if I am right? noun - Stanley, lizard, toothbrush. adjectives - sweet, fresh onions. The answer sweet,fresh. He suddenly realised where he'd seen the gold tube before. The...

*December 10, 2011*

**math**

A certain kind of bacteria doubles in quantity every hour. At midnight two nights ago. only two of these bacteria were in a jar. At midnight last night, the jar was full. At what time was the jar half full?

*December 9, 2011*

**science**

My question is ' what do you think if we lived in a world without any plants?' I have tried typing this in a search engine and it came up with nothing. Please could you help give me a website. Thank you.

*December 8, 2011*

**college physics**

I don't know where to begin with this question. Could someone help me please? A rod of mass 4.1 kg and length 1.6 m hangs from a hinge as shown in the figure below. The end of the rod is then given a "kick" so that it is moving at a speed of 5 m/s. How high will ...

*December 2, 2011*

**math**

(1A) Write the 11-digit number that has a 2 in the ones place,1 in the tens place,a digit in the ten-thousands place that is twice the digit in the ones place,the smallest odd digit in the billions place, 6 in the tenths place, and 0 in all the other places. (1B) How did you ...

*November 30, 2011*

**3 grade math**

12+6=18

*November 30, 2011*

**Algebra 2**

Show that for any complex number z, |z| = |-z|. (Hint: Let z = a + bi.)

*November 30, 2011*

**math**

ben has finished homewok during holiday.he does 2/3 of remaining question each days. after 4 days, 4 question are left .how many question he all together to do ?

*November 27, 2011*

**Physics**

A ball, of mass 0.3Kg, is held on the inside of a smooth hemispherical bowl at a height 0.15 m above the base. It is then released. Assuming there is no friction, the acceleration due to gravity, g, is 10 m/s2 and the potential energy is zero at the base of the bowl - What is ...

*November 22, 2011*

**Math61**

R is bounded by Y=2x-x^2 and the x-axis. Find the centroid of R. Sketch the region.

*November 16, 2011*

**physics**

Two forces, 422 N at 24 and 278 N at 29 are applied to a car in an effort to accelerate it. mass of the car is 3000kg Find the resultant of these two forces. Answer in units of N Find the direction of the resultant force (in relation to forward, with counterclock- ...

*November 12, 2011*

**Biology**

Which functional group is most likely to be responsible for an organic molecule behaving as a base (-OH donator / H+ acceptor)? A. Phosphate B. Amino C. Hydroxyl D. Carbonyl E. Carboxyl

*November 6, 2011*

**Biology**

If a protein's primary structure is predetermined or directed by a "source." what might this "source" be?

*November 6, 2011*

**Biology**

There are 20 amino acids that cells use to build the numerous amounts of proteins that are essential for life. If a protein molecule consisted of 100 amino acids, how many combinations are possible? What is the probability that out of the total possible combinations of the 100...

*November 6, 2011*

**event driven programming**

8. Write a visual basic program that accepts basic pay, allowances and tax of ten employees computes gross pay and net pay of each of the employee.

*November 2, 2011*

**Algebra 2**

When x² - 3x + 2k is divided by x + 2, the remainder is 7. Find the value of k. Use synthetic division to do so.

*October 28, 2011*

**math**

Joel and jacob are brothers. This year both of their ages are prime numbers. Last year both of their ages were composite numbers.Both of their ages will be composite numbers again over the next three years. If joel and jacob are both teenagers, how old are they now?

*October 27, 2011*

**Algebra 2**

When two rational expressions are divide, the quotient is 5x² + 3x + 12 + 7/(x + 5. What are the two polynomials?

*October 27, 2011*

**Algebra 2**

Please use the long division method for this problem.

*October 27, 2011*

**Algebra 2**

(4a³b + 5a²b² + a⁴ + 2ab³)÷ (a² + 2b² + 3ab)

*October 27, 2011*

**Science (urgent)**

Assuming you meant an arrow instead of a "Reserved" sign, it should be B, Product. The substrate is something being acted upon in a reaction (I'm assuming this is for a biology/biochemistry class, so in that case the substrate is what's being acted on by the ...

*October 26, 2011*

**physics**

I'm assuming you're referring to kinetic friction here, in either case (static or kinetic friction) however the following method is able to find the answer. Friction=mass*g*friction constant In this case the force of friction is equal and opposite to 20N, so Friction...

*October 26, 2011*

**physics**

Acceleration is equal to change in velocity over time. In this case the velocity is constant, so the change is 0. 0 divided by anything is 0, so there is no acceleration (a=0 /s^2)

*October 26, 2011*

**Physics**

You just need to calculate Jane's kinectic energy before she grabs the vine (.5mv^2). This will be equal to her gravitational potential energy (mg*height) at the top of her swing. .5mv^2=mgh -cancel the mass on both sides .5v^2=gh 19.22=9.8h h=1.96

*October 24, 2011*

**physics**

objects of masses m1=4 kg and m2=9kg are connected by a light string that passes over a frictionless pulley. the object m1 is held at rest on the floor and m2 rests on a fixed incline of delta=40 degrees. the objects are released from rest and m2 slids 1.00 m down the ...

*October 23, 2011*

**physics**

A falling skydiver has a mass of 123 kg. (a) What is the magnitude of the skydiver's acceleration when the upward force of air resistance has a magnitude that is equal to one-fourth of his weight? 7.35 m/s^2 (b) After the parachute opens, the skydiver descends at a ...

*October 21, 2011*

**Physics**

A box is sliding up an incline that makes an angle of 12.0° with respect to the horizontal. The coefficient of kinetic friction between the box and the surface of the incline is 0.180. The initial speed of the box at the bottom of the incline is 1.30 m/s. How far does the ...

*October 21, 2011*

**Algebra 2**

Factor. -16 + 17(5-y²)-(5-y²)² and [x + y + 1][x² - x(y + 1)+(y + 1)²

*October 20, 2011*

**Algebra 2**

Factor. (y-1)⁴ - (y-1)²

*October 20, 2011*

**Algebra 2**

Factor.

*October 20, 2011*

**Algebra 2**

1/16(x)^3a + 1/2(y)^(6a)(z)^(9b)

*October 20, 2011*

**Algebra 2**

Factor. 2x⁴ + x³ + 2x² + 4x - 24

*October 20, 2011*

**Algebra 2**

Solve for x. x³ + ax² - a²x - a³ = 0

*October 18, 2011*

**Algebra 2**

Solve for x. 2x² - 5bx + 4cx - 10bc = 0

*October 18, 2011*

**simple math**

1:3 and 1:2 Which one is a larger ratio? What does it mean for a ratio to be larger or smaller? Thank you.

*October 18, 2011*