Thursday
December 8, 2016

# Posts by darren

Total # Posts: 107

math
A step ladder 2.2m high was opened making an angle of 30° Calculate distance between legs of ladder
October 5, 2016

chemistry
If 10.0 L of butane and oxygen are combined at the same temperature and pressure, which gas will be left over after reaction? Include your calculation/reasoning.
September 24, 2016

math ples help
March 5, 2016

Chemistry, pH
im confused, is the answer 1.77827941x10^-10 or 5623413252????
March 8, 2015

Chemistry, pH
What is the (OH-) when pH = 4.25
March 8, 2015

Calculus
Ohh I see. Thank you!
September 30, 2014

Calculus
I'm a little confused though.. Where did you get the (1/7) and (1/5) in the second line?
September 30, 2014

Calculus
Thank you Reiny!
September 30, 2014

Calculus
Hi. I need help with finding the derivative of the function: y= [(sec^7 x)/7] - [(sec^5 x)/5] Thanks!
September 30, 2014

Calculus
Thanks Sarah!
September 30, 2014

Calculus
Hi! I need help finding the derivative of this function. f(x)= ln [(x(x-1))/(x-2)] Thank you.
September 30, 2014

Math
Given the following prime factors, determine the original number as well as all of its factors. 2*3*5*7 I know that 2*3*5*7 is 210 but I don't know what to do next.
September 29, 2014

math
September 24, 2014

Psychology
Indicate the independent variable and dependent variable: A research psychologist, working in a federal prison, is asked to assess the effectiveness of a new life skills program in promoting problem-solving skills. From a pool of 70 inmate volunteers, the psychologist randomly...
October 8, 2013

Geometry
A diver is currently at the surface of the water out at sea. If he descends into the ocean at an angle of depression of 32 degrees, what will be his depth to the nearest tenth of a foot after swimming for 5 minutes
June 15, 2013

Physics
Physics Help!!!!! Maximum Kinetic Energy based on a graph? A 2.50kg ball is attached to an unknown spring and allowed to oscillate. The figure shows a graph of the ball’s position x as a function of time t.(Figure 1) Part A: What is the maximum kinetic energy of the ...
May 1, 2013

U.S/history AP
Hi, what are evidence of the 2 superpowers in the cold war.
April 14, 2013

statistics
Given that the general population is normally distributed on a standard scale measuring math aptitude with Mean = 50 (s.d. = 10), approximately what percentage of the population has a math aptitude score between 40 and 60?
March 3, 2013

Calc
Find the area between the x axis and the graph of y = (2e^x)/(1+e^(2x)) a. e^2 b. pi c. pi/2 d. 2pi d. none of the above
January 25, 2013

Calc
Calculate the area under the curve y=e^-x above the x axis on the interval [1, infinity). a. infinity b. 0 c. -1/e d. 1/e e. none of the above
January 25, 2013

Calc
Evaluate the integral or show that it diverges: Integrand 0, lower, to 3, upper, (1/x)dx. a. infinity b. negative infinity c. 0 d. ln 3 e. none of the above
January 25, 2013

Calc
Find the limit as x approaches 0: (e^x^2-1)/(2x^2) a. 0 b. 1/2 c. infinity d. does not exist e. none of the above
January 25, 2013

Calc
Evaluate the integral (3x+4)/[(x^2+4)(3-x)]dx a. (1/2)ln(x^2+4) + ln|3-x| + C b. (1/2)arctan(x/2) + ln|3-x| + C c. (1/2)arctan(x/2) - ln|3-x| + C d. ln|(sqrt(x^2+4)/(3-x))| + C e. None of the above
January 25, 2013

Calc
Compute the average value of f(x) = x/(x+3) over the interval [-a,a], 0 < a < 3. a. 1 + (3/2a)ln[(3-a)/(3+a)] b. 2a + 3ln[(3-a)/(3+a)] c. 3/(9-a^2) d. 1/(2a) e. None of the above
January 25, 2013

Math
93*3^2-6^2-4^3
January 7, 2013

math
the gift box fits 2 layers of 10 cubic inches. what is the volume of the box.
December 16, 2012

Physics
Calculate a space shuttle territory 250 km above Earth's surface. Earth's mass is 6.0 * 10^24kg and its radius is 6.38 * 10^6 m (6380km)
October 18, 2012

Physics
A 1800-kg car experiences a combined force of air resistance and friction that has the same magnitude whether the car goes up or down a hill at 28 m/s. Going up a hill, the car's engine produces 52 hp more power to sustain the constant velocity than it does going down the ...
October 15, 2012

x+y=180 y= x+38 x+(x+38)= 180 2x+38=180 -38 =-38 2x = 142 x= 71 plug it in equation 71+71+38= 180 angle 1 = 71 angle 2 = 109
September 6, 2012

angle 1= x angle 2=8x so 8x+x=180 9x=180 9x= 180 divided by 9 is 20 so x=20 angle 1=20 angle 2=160 Hope it helps :)
September 6, 2012

You know complementary angles add up to 90 degrees so let x = one angle let 3x = the other angle x + 3x = 90 4x = 90 x = 22.5 degrees so one angle (x) is 22.5 and the other (3x) is (3 x 22.5) = 67.5
September 6, 2012

Math
An external sinusoidal force is applied to an oscillating system which can be modelled by a model spring and a damper. The general solution of the equation of the motion is given by, x = 5 + 3.071cos(2πt – β) + 3.14exp(-7.96t) cos(αt + φ) where α...
September 3, 2012

Math
A particle A of mass 2.11 kg collides with another particle B of mass 3.86 kg. Their initial velocities are u1 = 2.16i + 0.88j and u2 = 0.7i + 1.12j just before impact. After collision, they both merged and becomes a composite particle, which travel with a velocity of V. ...
September 3, 2012

Physics
the speed of sound in air is 343 m/s. using the relationship: 5280 feet in a mile, 3 feet in a yard and 3.3 feet in a meter. how many meters is this?
June 12, 2012

Algebra 2
(x^3+8) x ((x-2)/(x^2-2x+4))/ (x^2-4)/(x-6)
March 5, 2012

Statistics
The average age of vehicles registered in the united states is 96 months, with a standard deviation of 16 months. If a random sample of 36 vehicles is selected, find the probability that the mean of their ages is between 90 and 100 months. Provide four places past the decimal ...
March 4, 2012

chemistry
The purity of a pharmaceutical preparation of sulfanilamide, C6H4N2O2S, can be determined by oxidizing the sulfur to SO2 and bubbling the SO2 through H2O2 to produce H2SO4. The acid is then titrated with standard NaOH. Calculate the purity (%w/w sulfanilamide) given that 1.457...
February 15, 2012

chemistry
A 0.4515 g sample of pure CaCO3 was transferred to a 500 mL volumetric flask and dissolved using 6M HCl then diluted to volume. A 50.00 mL aliquot was transferred to a 250mL Erlenmeyer flask and the pH adjusted. Calmagite was used as an indicator the solution was titrated ...
February 15, 2012

chemistry
The amount of Fe in a 2.0008 g sample of an iron ore was determined by a redox titration with K2Cr2O7. The sample was dissolved in HCl and the iron brought to a +2 oxidation state. Titration required 26.48 mL of 0.034 M K2Cr2O7. Calculate the iron content as %w/w Fe2O3. Cr2O72...
February 15, 2012

GPA help
if i had a 1.875 and i get a C to go up to a B what is my GPA? will it be a 2.0? i need help i want to play baseball.
January 23, 2012

English
if i had a 1.875 and i get a C to go up to a B what is my GPA?
January 23, 2012

French
Can someone please help edit my French? My French: Quelles matières étudiez-vous cette année ? Moi, je fais deux les maths, la chimie, la physique, l’anglais et le français. Je n’aime pas les maths parce que il y a beaucoup des devoirs ...
January 20, 2012

Algebra 2
You are designing a kit for making sand castles. You want one of the molds to be a cone that will hold 48π cubic inches of sand. What should the dimensions of the cone be if you want the height to be 5 inches more than the radius of the base?
December 30, 2011

math
24+1+1/8
December 5, 2011

chem
What volume of a 8.50M Na2CO3 solution would be required to prepare 220.00mL of a 8.20%w/v Na2CO3 solution?
November 29, 2011

chem
mix 35.50 mL of a 0.201 M solution of K2CrO4 with 35.50 mL of a 0.201 M solution of AgNO3, what mass of solid will form?
November 29, 2011

A 40.6-kg crate rests on a horizontal floor, and a 69.1-kg person is standing on the crate. Determine the magnitude of the normal force that (a) the floor exerts on the crate and (b) the crate exerts on the person.
November 29, 2011

physics
In a European country a bathroom scale displays its reading in kilograms. When a man stands on this scale, it reads 90.4 kg. When he pulls down on a chin-up bar installed over the scale, the reading decreases to 79.5 kg. What is the magnitude of the force he exerts on the chin...
November 29, 2011

phsyics
A 40.6-kg crate rests on a horizontal floor, and a 69.1-kg person is standing on the crate. Determine the magnitude of the normal force that (a) the floor exerts on the crate and (b) the crate exerts on the person.
November 28, 2011

physics
In a European country a bathroom scale displays its reading in kilograms. When a man stands on this scale, it reads 90.4 kg. When he pulls down on a chin-up bar installed over the scale, the reading decreases to 79.5 kg. What is the magnitude of the force he exerts on the chin...
November 28, 2011

physics,
A student presses a book between his hands The forces that he exerts on the front and back covers of the book are perpendicular to the book and are horizontal. The book weighs 30.8 N. The coefficient of static friction between his hands and the book is 0.424. To keep the book ...
November 28, 2011

Phsyics
A 40.6-kg crate rests on a horizontal floor, and a 69.1-kg person is standing on the crate. Determine the magnitude of the normal force that (a) the floor exerts on the crate and (b) the crate exerts on the person.
November 28, 2011

Math- Pre calculus
A community bird-watching society makes and sells simple bird feeders to raise money for its conservation activities. The materials for each feeder cost \$5, and the society sells an average of 20 per week at a price of \$9 each. The society has been considering raising the ...
November 1, 2011

algebra
The product of two consecutive positive even numbers is 840. What are the numbers? (Enter solutions from smallest to largest.)
October 22, 2011

Math
Solve the equation. (Enter solutions from smallest to largest. If there is no solution, enter NONE in the answer boxes.) 4x^2 = 7x + 2
October 22, 2011

Physics
You are holding a 5 kg dumbbell straight out at arm's length. Assuming your arm is 0.63 m long, what torque is the dumbbell exerting on your shoulder?
October 10, 2011

math
I'm having trouble solving this problem: definite integral (2-t)(sqrt(t)), 0..2
September 24, 2011

Math
What property changed(4c + 3c) + 6 to (4+3)c + 6?
September 11, 2011

pre- algebra
It's -5m not 5m
May 19, 2011

pre- algebra
Solve for m. -6m - 7 = -5m + 3
May 19, 2011

Physics
Suppose you wish to visit a star which is 450 light years away, and that you want your 21000 kg rocket to move so fast that you only age 20 years during the round trip. a. How fast must the rocket travel relative to the Earth? Give your answer as the fraction of the speed of ...
May 5, 2011

Physics
a)What speed must one frame of reference be moving relative to another for the two to disagree about the length by 1% b)What speed must one frame of reference be moving relative to another for the two frames to disagree about time intervals by 1%? Both answer should be ...
May 5, 2011

Physics
At what speed must one frame of reference be moving relative to another for the two frames to disagree about lengths by 1%? Express your result as a fraction of the speed of light. At what speed must one frame of reference be moving relative to another for the two frames to ...
May 3, 2011

Physics
A rocket cruising past Earth at 0.79c shoots two bullets at 0.92c relative to the rocket with one of the bullets fired along the direction of the rocket's motion and the other fired opposite the rocket's motion. (a) What velocity does an Earth-based experimenter ...
April 29, 2011

Math
An airplane takes off in a straight path. When it has traveled 5 km, it is 3 km high. To the nearest kilometer, what is the horizontal distance, d that the airplane has flown over?
April 28, 2011

chemistry
A 0.040M solution of a weak acid has a pH of 3.02 at 25°C . What is the value of Ka for the acid?
March 15, 2011

chemistry
What are the concentrations of H3O+ and OH- and what is the pH of a 0.15 M solution of Na2CO3 (at 25 °C).
March 15, 2011

accounting
I'm stumped in reference to figuring the answer for the following question. If anyone can help I would be so thankful. The question is as follows: A county fire department receives property tax revenue on a 55% (December), 40% (April), 5% (June) basis. The uncollectible ...
January 2, 2011

Media Studies
Hi there, I need to make a response to this quote, could anyone give me ideas of what this quote might mean in relation to media today. "The Internet is to News, What Car Horns are to Music" Thanks.
November 17, 2010

english
-confidence/self esteem...well it seems to be the most obvious... sorry if it doesn't help
November 16, 2010

Algebra
or... 3x^2 -12x+ 36 = 35 (x-6)^2 = 35 x-6 = square root of 35 x= 6+ or 6- the square root of 35
November 16, 2010

MATH HELP ME 1st
Hey. Don't insult the people trying to help you. Just because you don't take notes, there's no reason for you to lash out. It's communitive because the order doesn't matter if you put it 4*1 or 1*4, it still produces a product of 4
November 16, 2010

math
(2,0) and (0, 8/7)
November 16, 2010

vocabulary
I saw a pair of pares Two to go is too much
November 16, 2010

language
Nope. possessives are the following it he she they you I
November 16, 2010

algebra
y= -2x-13 x= 5.5 -1/2y
November 16, 2010

Language
our describes that it's your team not mine ;) ur right :)
November 16, 2010

health
When HIPAA requires auhtorization to disclose information the authorization must
November 5, 2010

Englsih, Sonnets
Can someone help me with Sidney Sonnet 31 and 39 questions? The sonnets are at the bottom if you need them. 1. The unifying theme of Sidney's Sonnets 31 and 39 is... a. natural beauty b. hopeless love c. relief from pain d. endless suffering 2. Which of the following is a ...
October 28, 2010

algebra
-11 =z/-2 (-2)-11 =z z = 22
October 11, 2010

algebra
A person bought 17 gifts for his nieces and nephews. The gifts were dolls for the nieces at \$12.99 each, and robots for the nephews at \$10.99 each. The total spent was \$198.83. How many of each gift was bought?
October 1, 2010

scientist needs 5L of 12% solution. She has on 10% and 17% solution. How much of each does
October 1, 2010

math
dontknow
July 10, 2010

Vectors
Could someone help me solve these system using elementary operations, I am having trouble with both of them. x+y+z =0 x-y =1 y-z =-5 (For the one above the answer is (-1,-2,3) 2x-y =0 2y-z =7 2z-x =0 (For the one above the answer is (2,4,1)
June 1, 2010

Vectors
Thank You Reiny, that's exactly what I got. But I was told the number isn't a nice one, I believe that it's correct. Also, I have another question to ask. Find the intersection of the 2 planes (2x-2y+5z+10=0) and (2x+y-4z+7=0). So far, I eliminated x by subtracting...
May 25, 2010

Vectors
Could you please help me solve this question: Solve this system of equations using elementary operations. 1. x/3 + y/4 + z/5 =14 2. x/4 + y/5 + z/3 =-21 3. x/5 + y/3 + z/4 =7 So far, I have multiplied all three equations by 60, to turn them into whole numbers. Then everytime I...
May 25, 2010

Biology
Why is there electrical activity in the brain? Describe how it is used by neurons.
May 16, 2010

English
Hi there, I am doing a presentation comparing women in Hamlet times to women today. But i need help finding a cartoon representing women from Hamlet's time. Please direct me to links for this.
May 11, 2010

Vectors
A mass 0f 10kg is suspended by 2 pieces of string, 30 cm and 40 cm long, from twp points that are 50cm apart and at the same level. Find the tension in each piece of string.
May 5, 2010

neighborhood know how!
all neigh have rights.with these rights come responsibilities.draw a picture of a responsible neighbor.
March 24, 2010

bsa 375
Why is a systems development process needed? What is the objective of each phase of the SDLC? Describe briefly? How important are feasibility studies. The text mentions four types of feasibility studies: operational, technical, economic, and schedule. In your own words, how ...
March 20, 2010

cummunity helper project
my cummunity helper is a
March 1, 2010

kindergarten
neighborhood know-how!
February 8, 2010

Social Studies
what would happen if wheat was no longer a resource to the U.S.
April 30, 2009

out of curiosity...
does anyone know what is the pathway used to board an airplane? the bridge-like pathway that connects to the doors of the plane and are used to board and go off the plane? answer would be greatly appreciated..tnx :)
March 12, 2009

Intro to Accounting
Les Fleurs, a boutique in Paris, France, had the following accounts in its accounting records at December 31, 20X2 (amounts in Euros, denoted as "E") Purchases………………... E250,000 Freight In……………… E8,000 Sales...
March 3, 2009

diction
what is the opposite of cohesive but still using cohesive in it incohesive?
November 12, 2008

Naming
what are people from rhode island called? rhode islanders?
November 12, 2008

writing
facilities?
September 9, 2008

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