# Posts by Darren

Total # Posts: 111

**Maths**

A square prism and square pyramid have the same base and the same surface area. Show that the slant height, l, of the pyramid is l=5/2 x s where s is the length of the base.

**algebra**

5:11 and 6:12 7:13 and 21:39 8:14 and 24:30 10:20 and 20:30 which pair of ratios form a proportion?

**math**

A step ladder 2.2m high was opened making an angle of 30° Calculate distance between legs of ladder

**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.

**math ples help**

Please help.. How to answer if.. 2log8/6 + 2^2log3 - 2log12 Thank you so much

**Chemistry, pH**

im confused, is the answer 1.77827941x10^-10 or 5623413252????

**Chemistry, pH**

What is the (OH-) when pH = 4.25

**Calculus**

Ohh I see. Thank you!

**Calculus**

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

**Calculus**

Thank you Reiny!

**Calculus**

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

**Calculus**

Thanks Sarah!

**Calculus**

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

**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.

**math**

I don't know the answer

**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...

**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

**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 ...

**U.S/history AP**

Hi, what are evidence of the 2 superpowers in the cold war.

**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?

**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

**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

**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

**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

**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

**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

**Math**

93*3^2-6^2-4^3

**math**

the gift box fits 2 layers of 10 cubic inches. what is the volume of the box.

**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)

**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 ...

**Math (Please help immediately)**

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

**Math (Please help immediately)**

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 :)

**Math (Please help immediately)**

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

**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...

**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. ...

**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?

**Algebra 2**

(x^3+8) x ((x-2)/(x^2-2x+4))/ (x^2-4)/(x-6)

**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 ...

**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...

**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 ...

**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...

**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.

**English**

if i had a 1.875 and i get a C to go up to a B what is my GPA?

**Higher Chem**

16.11008228

**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 ...

**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?

**math**

24+1+1/8

**chem**

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

**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?

**phsyics HELP PLEASE**

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.

**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...

**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.

**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...

**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 ...

**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.

**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 ...

**algebra**

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

**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

**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?

**math**

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

**Math**

What property changed(4c + 3c) + 6 to (4+3)c + 6?

**pre- algebra**

It's -5m not 5m

**pre- algebra**

Solve for m. -6m - 7 = -5m + 3

**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 ...

**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 ...

**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 ...

**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 ...

**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?

**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?

**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).

**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 ...

**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.

**english**

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

**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

**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

**math**

(2,0) and (0, 8/7)

**vocabulary**

I saw a pair of pares Two to go is too much

**language**

Nope. possessives are the following it he she they you I

**algebra**

y= -2x-13 x= 5.5 -1/2y

**Language**

our describes that it's your team not mine ;) ur right :)

**health**

When HIPAA requires auhtorization to disclose information the authorization must

**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 ...

**algebra**

-11 =z/-2 (-2)-11 =z z = 22

**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?

**10th grade**

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

**math**

dontknow

**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)

**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...

**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...

**Biology**

Why is there electrical activity in the brain? Describe how it is used by neurons.

**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.

**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.

**neighborhood know how!**

all neigh have rights.with these rights come responsibilities.draw a picture of a responsible neighbor.

**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 ...

**cummunity helper project**

my cummunity helper is a

**kindergarten**

neighborhood know-how!

**Social Studies**

what would happen if wheat was no longer a resource to the U.S.

**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 :)

**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...