Friday

December 19, 2014

December 19, 2014

Total # Posts: 495

**Trig**

the angle of elevation to the sun is 65 degrees. A building casts a shadow 16m long. What is the height of the building to the nearest meter?
*November 17, 2014*

**Algebra**

You invest an initial $4,500 in an account that has an annual interest rate of 4.5%, compounded daily. How much money will you have in the account after 10 years? Round your answer to the nearest whole number.
*November 12, 2014*

**calculus**

Use l'hopital's Rule to evaluate lim x in 0 of (4x(cos 6x-1 )) / sin 3x-3x
*November 8, 2014*

**math**

Richard put a counter on 6. He counted by tens. what are the next 3 numbers he counted? My answer is: 16, 26, 36
*November 3, 2014*

**calculus**

never mind i got it thanks
*November 3, 2014*

**calculus**

A spotlight on the ground is shining on a wall 24m away. If a woman 2m tall walks from the spotlight toward the building at a speed of 1.2m/s, how fast is the length of her shadow on the building decreasing when she is 4m from the building?
*November 3, 2014*

**Algebra**

Find the dimensions of the rectangle of the largest area that can be enclosed by 200 meters of fencing
*October 27, 2014*

**calculus**

The volume of a cube is increased from 729 cubic centimetres to 849.285 cubic centimetres. Use differentials to determine: a) by approximately how many centimetres the side length of the cube increases ? B) by approximately how many square centimetres does the surface area of ...
*October 12, 2014*

**Calculus**

The volume of a cube is increased from 729 cubic centimetres to 849.285 cubic centimetres Use differentials to determine : (a) by approximately how many centimetres does the side length of the cube increase? (b)by approximately how many centimetres does the surface area of the...
*October 11, 2014*

**Logic**

mushroom & purple => poisonous mushroom & poisonous => purple mushroom & ~purple => ~poisonous mushroom & purple => ~poisonous
*October 6, 2014*

**physics**

An electron travels 2.7 m in 6.37 × 10−8 s. How fast is it traveling?
*September 30, 2014*

**CHEM**

In the preparation of a rock salt solution, 1.522 grams of impure rock salt was dissolved in 50.0 ml of distilled water. The total mass of the solution was found to be 51.522 grams. Calculate the weight percent of impure rock salt in the prepared solution.
*September 26, 2014*

**math**

I have a 15ft board I need to cut into 2 1/8 inch pieces how many can I cut
*September 17, 2014*

**Maths**

How would you convert 11 minutes into hours?
*September 14, 2014*

**Grade 10 Maths**

An area for planting crops is given by: A = 800 + 20x - 1/2x^2 Find the value of x which the area is a maximum
*September 11, 2014*

**physics**

bob pursley, can you answer my question. SCIENCE BIOLOGY. My name is Julia. THanks. I have till 12 am. HELPPPP
*September 3, 2014*

**SCIENCE:BIOLOGY>**

bELIEVE ME OR NOT BUT i'M PRETTY SURE I HAVE MINE RIGHT.THX FOR YOUR HELP ..NOT! tHANKS DR.bOB222
*September 3, 2014*

**SCIENCE:BIOLOGY> **

1. How many seconds do you spend in school during the week (6.5 hours/day)? 2. How many micrograms are in 12 dekagrams? 3. How many centimeters are in 5 kilometers? 4. 3.25 liters are equal to how many kiloliters? 5. how man meters are in 0.65 hectometers? 6. How many grams ...
*September 3, 2014*

**chemistry**

Dr.Bob can you answer my questions. My name is Julia.. my topic is in Science:Biology
*September 3, 2014*

**History/ English**

please help!
*September 3, 2014*

**History/ English**

What does the novel 1984 by George Orwell teach us about history? In what ways is Winston a historian?
*September 3, 2014*

**math**

Determine whether the system of equation is in row-echelon form. x-y+3z=-11 y+8z=-12 z=-2
*June 17, 2014*

**Math**

A hair product company sells three types of hair products for $30, $20, and $10 per unit. In one year, the total revenue for the three products was $800,000, which corresponded to the sale of 40,000 units. The company sold half as many units of the $30 product as units of the...
*June 17, 2014*

**Chem**

Oops 0.10 mol NaOH
*May 27, 2014*

**Chem**

When 1.10 mol of NaOH is added to 1.00 L of 0.30 M HCl the pH of the resulting mixture is: a) 0.52 b) 0.70 c) 1.00 d) 13.30
*May 27, 2014*

**Scientific Method**

B is the correct answer
*May 25, 2014*

**English**

Choose the answer that identifies the function of the gerund in the sentence. Yes, this player has worked hard on improving his strength this season.
*May 24, 2014*

**Chemistry**

Thanks :)
*May 17, 2014*

**Chemistry**

Explain why methyl red would be a good indicator for a titration of 0.25M NaOH with .025M HNO3, but a poor choice for use in a titration of 0.25M NaOH with 0.25M HCN. I'm pretty sure the first step is to find the pH of the two titrations (and then compare those to the pH ...
*May 17, 2014*

**math**

I'd convert it to minutes. 14x60=840 (plus the 3 minutes)=843minutes Divide 843 by 3 = 281minutes Then convert back to hours and minutes... 281 divided by 60 = 4hr (leave out the decimals since they represent the left over minutes) 4x60=240 (this is the time already ...
*May 17, 2014*

**Math**

175g AgCl x (1 mol/247.9g) x (1 Ag2S/2AgCl) x (143.4g/1 mol) = 50.615g Ag2S I'm assuming you've learned about basic stoichiometry and how to use mole bridges? Otherwise this type of question wouldn't be asked.
*May 17, 2014*

**math **

Terry wants to buy one pair of moccasins. She can choose from some that costs $22.50, $27.00, $20.95, and $24.75. How much will Terry save if she buys the least expensive instead of the most expensive pair?
*April 29, 2014*

**MATH**

Thank you.
*March 26, 2014*

**MATH**

14% of what number is 84?
*March 26, 2014*

**CHEM**

Can you show me the formula I need to do this problem. please a solution is made by dissolving 0.35 mole of LiI in enough water to give a final volume of 2.60 ml. What is the molarity of the solution? thank you
*March 25, 2014*

**CHEM**

can you show me the formula for this problem. calculate the grams of NaOH present in 9.0 ml of a 8.0 (m/v) NaOH solution. thank you
*March 25, 2014*

**chemistry**

Calculate the concentration in % (m/m) of a solution containing 20.5 g of LiF dissolved in 340.0 g of H2O. a.1.14% (m/m) b.5.69% (m/m) c.6.03% (m/m) d.6.42% (m/m)
*March 23, 2014*

**chemistry**

In which of the following pairs of ionic compounds are both members of the pair soluble in water? a.AgNO3 and AgCl b.LiOH and Li2SO4 c.PbSO4 and BaCO3 d.NH4I and Sn3(PO4)2
*March 23, 2014*

**Math**

Write in order from least to greatest. +3,-1,-4,+2,0
*March 18, 2014*

**Physics**

Block A in the figure weighs 48.0N . The coefficient of static friction between the block and the surface on which it rests is 0.250. The weight w is 6.00N and the system remains at rest. -Find the friction force exerted on block A. -Find the maximum weight w for which the ...
*March 8, 2014*

**physics**

A driver drives 2.5 hours at an average speed of 48MPH. What distance does she travel in this time?
*February 10, 2014*

**physics**

A driver drives 2.5 hours at an average speed of 48MPH. What distance does she travel in this time?
*February 10, 2014*

**math**

If x varies inversely withy 3, and x=6 when y=3, find x when y=2.
*February 4, 2014*

**math**

A robotic basketball player tosses a ball upward from a height of 7 feet, at an initial speed of 111 feet per second. The height of the ball is modeled by the equation: h=−16t2+111t+7, where h is the height above the ground in feet and t is the time measured in seconds. ...
*February 4, 2014*

**math**

You are putting a brick walkway along two sides of a rectangular garden that measures 6 meters by 15 meters. The path will run the length of the garden, turn the corner, and run along the width. You only have enough brick to cover 46 square meters. How wide should the border be?
*February 4, 2014*

**Math**

Mushrooms produce a tremendous number of spores. However, very few spores go on to establish a new mushroom colony. A "colony" is actually a little bunch of fuzzy-looking cells called a mycelium. Let's say a particular mushroom produces a billion spores in a day...
*January 1, 2014*

**Math**

Uncle Joe made chocolate chip cookies. Eric ate fifty percent of them right away. Ryan ate fifty percent of what was left. Ten cookies remain. How many cookies did Uncle Joe make?
*January 1, 2014*

**Math**

There are three hundred students at Mackenzie Middle School in Brain City. If 57% of the students are female, what is the ratio of female students to male students? Answer in lowest terms
*January 1, 2014*

**Math**

The local election is over and a new mayor has been elected to lead Big Town. The new mayor received three votes for every vote received by her opponent. The new mayor received 2,541 votes. How many votes did her opponent receive?
*January 1, 2014*

**Physics**

A train is moving parallel and adjacent to a highway with a constant speed of 27 m/s. Ini- tially a car is 60 m behind the train, traveling in the same direction as the train at 41 m/s and accelerating at 5 m/s2. What is the speed of the car just as it passes the train? Answer...
*October 16, 2013*

**Physics**

r << 1.3e-4
*October 15, 2013*

**physics**

KE = (1/2)(m)(v)^2 = (0.5)(4)(5)^2 = 50 J Constant friction force encountered: N = (0.94)(4)(10) = 37.6 N Energy absorbed by friction: Fd = 37.6x Energy absorbed by the spring: =(1/2)(17)(x)^2 =8.5x^2 Final Equation: 50 = 8.5x^2+37.6x 0 = 8.5x^2+37.6x-50 Solve the quadratic ...
*October 15, 2013*

**physics**

r^3 << (3*(C_1)^2)/(4*pi*C_2*oil density*g) r^3 << (3)*(2.30e-4)^2 / (4)(3.14)(0.88)(660)(10) r << 1.3e-4
*October 15, 2013*

**Algebra 1**

One long-distance telephone company offers a plan such that the first 20 minutes costs $.99 and each additional minute costs $.09. Solve an inequality to find the maximum amount of full minutes you can talk for $5.00. At first I got: 5 is greater than or equal to .99+(1.8-.09m...
*October 14, 2013*

**physics**

Hello Can you explain the first equation? distance=V(t-10)+V/2 * 10 Where is this distance coming from for me to be able to solve for V? Also where is the 10 coming from in V(t-10) and V/2*10? My final equation solving for V is : V= 10d / 4(t-10)
*October 5, 2013*

**US History**

What political influences shaped the governments of the British Colonies
*October 1, 2013*

**Geometry proving quadrilaterals **

Proving quadrilaterals PLEASE PLEASE PLEASE HELP *the diagonals of a square bisect the vertex angle * the diagonal of a rhombus are perpendicular *each diagonal of a rhombus bisects the opposite angles of the rhombus help me prove please how ? tell me
*September 30, 2013*

**Math 6th Grade Level**

A baker bought 680,000 oz. of flour and packed the flour into 200 bags of equal size. He used some flour and had 100 bags left. He decided to repack the remaining flour bags into bags of 5,000 oz. bags. How many bags of flour did he have in the end?
*June 19, 2013*

**Math **

Mei packed 783 strawberries equally into 9 cartons. After giving 4 cartons to her neighbors, she decided to repack 5 strawberries into each carton. How many cartons of strawberries did she have in the end?
*June 19, 2013*

**Math**

A homeowner empties her hot water heater every 36 days and changes the filter in the heat pump every 48 days. She did both on Friday September 17, 2012. When again will she do both on the same day? (give the day of the week, the date, month, and year)
*June 17, 2013*

**physics**

The Easy Bake Oven is a common toy for young children who want to emulate the process of cooking. Suppose this oven is plugged into a 120 V electrical outlet and "cooks" the food by using a 144 ohm resistor light bulb that converts electrical energy to both light and...
*May 30, 2013*

**organic chemistry**

for each of the following compounds, draw the form in which it will predominate at ph=3, ph=6, ph=10, and ph=14. a)CH3COOH b)CH3CH2NH3 c) CF3CH2OH please explain how to get answers. my book does not give clear examples.
*May 30, 2013*

**BIOLOGY!!!!!!**

What is the reletive amounts of mRNA that will e transcribed if there is no promoter and enhancer?
*May 22, 2013*

**French**

Help me conjugate this in French? Need help Atterrir, tu Fleurir, les plantes Fondre, les garcons Perir, les fleurs Penser, tu Manger, vous Verifier, les professeurs Marcher, le chat noir
*May 16, 2013*

**math**

I need 2 three digit numbers that total 16848
*April 22, 2013*

**finance**

Mrs. Kay who is 24 years old plans to retire at the age of 60. Mrs. Kay would like to be able to withdraw $120,000 per year from her retirement account for 40 years after retirement beginning a year after her retirement. She already has $15,000 in her retirement investment ...
*April 17, 2013*

**chemistry**

What is the specific heat of an unknown substance if a 2.31 g sample releases 12.5 cal as its temperature changes from 24.9°C to 20.7°C? Please explain ans show steps.
*April 16, 2013*

**math**

a storage crate has the dimensions : 12ft * 6ft *5ft. how many cube-shaped boxes measuring 8 inches in length could be stacked completely within the cube??
*April 10, 2013*

**Chemistry**

Enough of a monoprotic acid is dissolved in water to produce a 1.47 M solution. The pH of the resulting solution is 2.64. Calculate the Ka for the acid.
*April 10, 2013*

**adv functions**

Hi! I need help with determining the value of each of the following logarithmic expressions. Do not change the bases- thx a) log[base8]4 b)log[base(1/3)]27
*April 7, 2013*

**Physics**

if a toy car's motor propelled it 1.905m in 7.1 seconds and it kept rolling .38m for 8.6 seconds what is the coefficient of friction between the wheels and the floor assuming that is the only source of friction. i know accel=.08m/s2 and -.12m/s2 but after that i got lost.
*April 5, 2013*

**Physics- so confused!!**

I am not sure. I think the speeds are for the bullet before and after passing through the block. However, in the diagram the second block is in a different spot after the bullet hits it.
*March 23, 2013*

**Physics- so confused!!**

A bullet with a mass of 5.40 g is fired horizontally at two blocks resting on a smooth and frictionless table top as shown in the Figure. The bullet passes through the first 1.20 kg block, and embeds itself in a second 1.20 kg block. Speeds v1 = 3.90 m/s and v2 = 1.70 m/s, are...
*March 23, 2013*

**chemistry**

At 2273 K, Keq = 6.2 multiplied by 10-4 for the following reaction. N2(g) + O2(g) equilibrium reaction arrow 2 NO(g) If [N2] = 0.04700 mol/L and [O2] = 0.01200 mol/L, what is the concentration of NO at equilibrium? please answer and explain this one as well.
*March 11, 2013*

**chemistry**

please help and explain. At a certain temperature, Keq = 10.5 for the equilibrium below. CO(g) + 2 H2(g) equilibrium reaction arrow CH3OH(g) Calculate the following concentrations. (b) [H2] in an equilibrium mixture containing 1.01 mol/L CO and 0.335 mol/L CH3OH
*March 11, 2013*

**Chemistry**

I was taught that hydrogen bonds are actually very weak, but it may just be a matter of different teachers. I would answer C) Covalent Bonding because they SHARE an electron keeping them very close and tight.
*March 10, 2013*

**Science**

77.15 ....YAY GOOGLE!
*March 10, 2013*

**language**

Well this totally depends on the child. My younger siblings all started around six, but this could vary.
*March 10, 2013*

**Physics**

A 250N force is applied at an angle of 32 degrees above the horizontal to a 96kg box causing it to slide along a floor. The coefficient of friction between the box and the floor is 0.18. What is the magnitude of the net force on the box? The answer is 67N, I'm just not ...
*March 10, 2013*

**Physics**

A box is held against a wall (not resting on the ground). What minimum horizontal force will JUST prevent the 5.0kg box from sliding if the coefficient of friction betweent he wall and the box is 0.65?
*March 10, 2013*

**Biology**

A golgi body is used to package proteins and lipids into vesicles for transport, so it's probably a cell that produces proteins or lipids or both.
*March 10, 2013*

**social studies**

- languages - if their mother country went to war, would they join (eg. WWI (Canada): british immigrants wanted to join Britain, but french immigrants felt no connection to Britain and wanted to stay out of the war...) - school systems - religion ...the list goes on, I'm ...
*March 10, 2013*

**algebra I**

how do I solve for 16x^2+56x-120
*March 6, 2013*

**Algebra**

isn't it: [(26^4)+ (10^3)]-241
*March 6, 2013*

**french**

what is the weather like in Spring?
*March 2, 2013*

**German**

This IS grammatically correct, but it sounds weird (no offense :P). It means "I would rather put on make-up than he would", more or less. There would be better-sounding ways to say this although it is correct.
*March 1, 2013*

**math**

The application of one function followed by the application of a second function to the result of the first as in F^-1(f(x)) is called composition of functions. The two functions need not be inverse of each other. In a diagram, the output of one function is f(x) is used as the...
*February 10, 2013*

**physics**

The launching speed of a certain projectile is 3.0 times the speed it has at its maximum height. Calculate the elevation angle at launching
*February 8, 2013*

**Chemistry**

Thank you so much for the detailed steps. Finally understood what I need to do.
*February 7, 2013*

**Chemistry**

Calculate the value of Kp for the equation C(s)+CO2(g)<->2CO(g) Kp=? given that at a certain temperature C(s)+2H2O(g)<->CO2(g)+2H2(g) Kp1=3.33 H2(g)+CO2(g)<->H2O(g)+CO(g) Kp2=.733 Please show detailed steps.
*February 7, 2013*

**Physics please help!!**

A basketball player throws the ball at a 38° angle above the horizontal to a hoop which is located a horizontal distance L = 5.6 m from the point of release and at a height h = 0.4 m above it. What is the required speed if the basketball is to reach the hoop? Not sure how ...
*February 5, 2013*

**Physics please help!!**

A stone is aimed at a cliff of height h with an initial speed of v = 64.0 m/s directed 55.0° above the horizontal, as shown in the Figure below by the arrow. The stone strikes at A, 7.31 s after launching. What is the height of the cliff? What is the maximum height H ...
*February 5, 2013*

**Physics please help!!**

A person who is 1.4 m tall throws a ball with a speed of 4.2 m/s at an angle of 25 degrees above the horizontal. What are the x and y components of the velocity (in m/s) of the ball the instant before it strikes the ground? The acceleration due to gravity is 10 m/s2
*February 5, 2013*

**Physics please help!!**

The launching speed of a certain projectile is 9.0 times the speed it has at its maximum height. Calculate the elevation angle at launching.
*February 3, 2013*

**Physics please help!!**

A projectile is fired at 45.0° above the horizontal. Its initial speed is equal to 42.5 m/s. Assume that the free-fall acceleration is constant throughout and that the effects of the air can be ignored. What is the maximum height reached by the projectile? At what time ...
*February 3, 2013*

**Physics please help!!**

A person who is 1.4 m tall throws a ball with a speed of 4.2 m/s at an angle of 25 degrees above the horizontal. What are the x and y components of the velocity (in m/s) of the ball the instant before it strikes the ground? The acceleration due to gravity is 10 m/s2
*February 3, 2013*

**Language**

Oh, hahah, I wasnt thinking right. I looked back over the question and I am almost possitive that is it #3.
*January 29, 2013*

**Language**

Sorry, I dont understand what you are saying, What text?
*January 29, 2013*

**Language**

What are the three main parts of a research report? 1.title, body, conclusion 2.introduction, body, sources 3.introduction, body, conclusion 4.introduction, evidence, conclusion and I just need it checked, I believe that it is #4...is that right?
*January 29, 2013*

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