Friday

December 19, 2014

December 19, 2014

Total # Posts: 1,186

**Physics**

A block of mass m is pulled across a level surface by a rope that makes an angle θ with the horizontal. The coefficient of friction is μ. (a) Determine the amount of force F required to slide the block at a constant velocity. (b) Determine the optimum angle at which ...
*December 3, 2014*

**physics**

A man pushes 100.0 N on the handle of a 40.0 kg lawnmower. The applied force is in the same direction as the handle, which is tilted 35.0° relative to horizontal. The coefficient of kinetic friction is 0.10. Find the amount of acceleration.
*December 3, 2014*

**physics**

You create a plot of T2 (in s2) vs mass (in kg) and the linear fit of your graph gives a slope of 0.12735 ± 0.01234. What is the value of the spring constant you took the data with? i am not sure what to do. i know the k=1/slope but im not sure how to start to solve ...
*December 1, 2014*

**Chemistry**

Hi Chris, I believe I am in your Intro Chem class at Alfred State. To do this problem, all you have to do is substitute the equation C(s) V(s)= C(d) V(d)... C stands for the moles (concentration) and the V stands for the mL (volume) if you plug the numbers into the equation...
*November 29, 2014*

**math**

A tank holds 15 litres of water.A cup holds 3/10 of a litre. How many cups of water does the tank hold
*November 18, 2014*

**art/photography**

1. In sandy skoglunds THE COCKTAIL PARTY what was the artist contrasting? 2. What did the artist say about her work? 3. What does the artist deal with in all of her illustrations? 4. What happens to sandy skoglunds installations pieces and what become of the work of art? 5. ...
*November 9, 2014*

**Physics**

A 24.00 kg block at rest on a horizontal frictionless air track is connected to the wall via a spring. The equilibrium position of the mass is defined to be at x=0. Somebody pushes the mass to the position x=0.3500 m, then lets it go. The mass undergoes simple harmonic motion ...
*November 8, 2014*

**Algebra please help **

A grocery store sells snacks by weight. A six ounce bag of mixed nuts costs $3.60. Predict the cost of a two ounce bag. Please help answer
*November 4, 2014*

**Algebra please help answer**

Gina's art teacher mixes 9 pints of yellow paint with 6 pints of blue paint to create green paint. Gina mixes 4 pints of yellow paint with 3 pints of blue paint. Did Gina use the same ratio of yellow paint to blue paint instructed by her teacher? Explain. Is it 9/6 to 4/3...
*November 4, 2014*

**English**

Which of the following stylistic movement best represents Weird Al Yankovic's song Canadian Idiot? Would it be existentialism, modernism or postmodernism and why?
*November 3, 2014*

**finamce**

Define captital structure weights)Templeton extended care facilities, inc., is considering the acquisition of a chain of cemeteries for $400 million. Since the primary asset of this business is real estate, Templetons management has determined that they will be able to borrow ...
*November 2, 2014*

**Math**

On December 16, 1811, an earthquake occurred near New Madrid, Missouri, that temporarily reversed the course of the Mississippi River. The quake had a magnitude of 8.8. On October 17, 1989, a calamitous quake measuring 7.1 on the Richter scale occurred in San Francisco during ...
*October 31, 2014*

**Algebra please help out**

Would part B be 180/252, and would part C be 252/10? Please let us know if correct thx
*October 29, 2014*

**Algebra please help out**

Tomas makes balloons sculptures at a circus. In 180 minutes, he uses 252 balloons to make 36 identical balloon sculptures. Part A question how many minutes does it take to mAke one balloon sculpture? How many balloons are used in one sculpture? b. What is Toma's unit rate ...
*October 29, 2014*

**Algebra please help out**

Ed is using the recipe shown to make fruit salad. He wants to use 30 diced strawberries in his fruit salad. How many bananas, apples, and pears should Ed use in his fruit salad? The fruit salad recipe reads 4 bananas, diced, 3 apples diced, 6 pears diced and 10 strawberries ...
*October 29, 2014*

**Math**

If an object is propelled upward from ground level with initial velocity of 55 feet per second, it's height h in feet t seconds later is given by the equation H=-16t^2+55t. after how many seconds does the object hit ground?
*October 28, 2014*

**calculus**

Find the length and width of a rectangle that has the given area and a minimum perimeter. Area: 8A square centimeters
*October 26, 2014*

**COLLEGE PHYSICS**

An internal explosion breaks an object, initially at rest, into two pieces. One piece (m1) is 1.5 times more massive than the other (m2). If 7500 J were released by the explosion, how much KE did each piece acquire?
*October 22, 2014*

**Physics**

A rescue plane is flying horizontally at a height of 132 m above the ground. The pilot spots a survivor and releases an emergency kit with a parachute. The kit descends at a constant vertical acceleration of and the initial plane horizontal speed is . Assuming air resistance ...
*October 22, 2014*

**math**

The number 199,557 contains two sets of digits in which one digit is ten times as great as the other. What are the values of the digits in each set?
*October 15, 2014*

**English**

I have to write a 5 paragraph comparison and contrast essay on Agamemnon, Hamlet, and The Love song of J. Alfred Prufrock. When writing this, do I compare all three stories at once in each paragraph as well as their differences in each of the 3 body paragraphs?
*October 11, 2014*

**Math & Statistics**

Problem 6 [Total 5 marks] The drug Ziac is used to treat hypertension. In a large clinical trial it was found that 32% of those in the placebo group experienced dizziness. (a) [1 mark] Assuming that the same 32% proportion applies to subjects taking the drug, find the ...
*October 8, 2014*

**science**

An electron drop to what energy level is likely to emit a photon in the infrared region?
*October 4, 2014*

**Trigonometry**

A communications tower is located at the top of a steep hill, as shown. The angle of inclination of the hill is 58°. A guy wire is to be attached to the top of the tower and to the ground, 50 m downhill from the base of the tower. The angle α in the figure is ...
*October 1, 2014*

**Math **

List these numbers from least to greatest 7/3, 3/4, 2/3, 0.5, 1.3
*October 1, 2014*

**algebra**

the area of a rectangular picture frame is 30 1/3 square inches. the length of the frame is 6 1/2 inches.please help find the width of the frame. thanks
*September 29, 2014*

**algebra**

Dao has 2 3/8 pounds of hamburger meat. he is making 1/4 pound hamburgers. does Dao have enough meat to make 10 hamburgers? explain. thanks
*September 29, 2014*

**algebra**

Jeremy has 4 1/2 cups of iced tea. He wants to divide the tea into 3/4 cup servings. use the model to find the number of servings he can make. Please help answer question. thanks would it be 9/2 multiplied by 4/3
*September 29, 2014*

**math-pre calc**

On a drive from your home to town, you wish to average 48 mph. The distance from your home to town is 106 miles. However, at 53 miles (half way), you find you have averaged only 36 mph. What average speed must you maintain in the remaining distance in order to have an overall ...
*September 24, 2014*

**chemistry**

It's supposed to be "c" of liquid ,I'm sorry.
*September 23, 2014*

**chemistry**

A 50g chunk of metal (c=0.0506 j/g°C) is heated to 60°C. it is then dropped into a calorimeter(c=1.40 j/g°C,m=5.0 g)that contains 100.0g of an unknown liquid. the temperature of the liquid raises from 15°C to 20°C.What is the c of the calorimeter?
*September 23, 2014*

**physics**

2.91s
*September 16, 2014*

**algebra 1**

a number and its absolute value are equal.if you substract 2 from the number, the new number and its absolute value are not equal. what do you know about the number? what is a possible number that satisfies these conditions? Can you help answer these 2 questions? thanks
*September 10, 2014*

**algebra 1**

the deepest point in elevation in the indian ocean is the java trench, which is 25,344 feet below sea level. elevations below sea level are represented by negative numbers. can you help write the elevation of the Java Trench? also, a mile is 5,280 feet. Between which two ...
*September 10, 2014*

**algebra**

two students are playing a math game. the object of the game is to make the least possible number by arranging the given digits inside absolute value bars on a card. In the first round, each player will use the digits 3, 5, and 7 to fill in the card. One student arranges the ...
*September 10, 2014*

**Algebra**

If the absolute value of a negative number is 2.78, what is the distance on the number line between the number and its absolute value? can you help explain the answer. thanks
*September 10, 2014*

**Chemistry**

sorry I forgot to add the rest. I also have the concentration of NaOH which is 1.0 M, pKa is 4.4, and the volume of the acid is 25 mL
*August 17, 2014*

**Chemistry**

How would I find the concentration of an unknown acid if I have a Ka value of 3.98x10^-5?
*August 17, 2014*

**calculus**

A parallelogram is determined by the vectors a = [-2, 5] and b = [3, 2]. Determine the diagonals of the parallelogram.
*August 16, 2014*

**calculus**

Solved
*August 16, 2014*

**calculus**

Beth leaves a dock in a motorboat travelling at 14 m/s. She heads downstream at an angle of 40° to the current, which flows at 6 m/s. Determine how long it takes for Beth to travel 400 m
*August 16, 2014*

**SOLVED**

SOLVED
*August 16, 2014*

**calculus**

For the vectors x=(0,6,-5), y=(2,1,4) and z=(-2,3,-1) what is the value of (2x+y)·(3y-z)? (dot product question and each letter is a vector)
*August 16, 2014*

**calculus**

Nikki is driving a motorboat across a river that flows at 5 m/s. The motorboat has a speed of 12 m/s in still water. She heads out from one bank in a direction perpendicular to the current. How far does she travel in 3 minutes?
*August 16, 2014*

**calculus**

Determine (6i+2j)· (i-4j+k) This is a dot product question and each letter has the vector symbol
*August 16, 2014*

**Calculus (need help with only d and e)**

Codeine phosphate is a drug used as a painkiller. A common brand contains 30 mg of codeine. Samples of blood were taken at regular time intervals from a patient who had taken a pill containing 30 mg of codeine. The amount of codeine in the bloodstream was determined every 30 ...
*August 13, 2014*

**Chemistry**

I am given that volume of an unknown acid is 25 mL, volume of NaOH is 13 mL and concentration of NaOH is 1.0 M. I have a graph of a titration curve where the equivalence point is pH=9 (pH on y axis and volume of NaOH on x axis) How would i find the pKa value as well as the Ka ...
*August 13, 2014*

**Chemistry**

Ièm studying grade 12 chemistry and this is the Chemical Systems and Equilibrium
*August 8, 2014*

**Chemistry**

Thanks but not exactly, the question is asking what would happen if you had more than one product or reactant that was a gas
*August 8, 2014*

**Chemistry**

Can you please explain if it would be possible to calculate the K value if more than one product or reactant in a chemical equation is a gas?
*August 8, 2014*

**Chemistry**

I am to do an equilibrium constant lab and I am supposed to only find the Kc value. i have to find the equilibrium constant for NaHCO3 (s) <--> NaOH (s) + CO2 (g) at 800K. The partial pressure in the bulb reads 420 kPa on the manometer, 1 gram of NaHCO3 was added to the ...
*August 7, 2014*

**physics**

An astronaut in a spaceship is listening to his music. Calculate the time it takes to play a 4.00 minute song at 0.1c
*August 4, 2014*

**physics**

I need help with this question. Would you be able to explain it please? Double slit interference patterns exhibit mλ path difference for constructive interference. Single slit diffraction patterns exhibit (m+1/2)λ path difference for constructive interference. With ...
*August 4, 2014*

**physics**

Can you please explain how to solve this question? Would I need to use the formula nλ=dsin(theta)? Red light with a wavelength of 660 nm and blue light with a wavelength of 480 nm are beamed at a double slit with a separation of 2x10^-3 mm. The third order maximums for ...
*August 2, 2014*

**Chemistry- practice question**

The answer for this question is ΔHrxn=-441.40174468085 kJ/mol but I don't know how to arrive to that answer. 0.47g of magnesium reacts with 100ml of 1.00 mol/L HCl in the following reaction: Mg(s)+2HCl(aq)-->MgCl2(aq)+H2(g). The heat of reaction is -8537.4J ...
*August 1, 2014*

**physics**

At exactly the critical angle: a) all light reflects back into the n1 medium b) all light reflects back into the n2 medium c) part of the light reflects back into the n1 medium, the remainder travels along the boundary between the two mediums d) part of the light reflects back...
*August 1, 2014*

**Physics- check answer please**

A critical angle of 24.4 degrees applies to: a) light travelling from air into diamond b) light travelling from diamond into air c) light travelling from water into diamond d) light travelling from diamond into water Would the answer be a)?
*August 1, 2014*

**nursing**

In what ways does the World Health Organization assist healthcare?
*August 1, 2014*

**physics**

At exactly the critical angle: a) all light reflects back into the n1 medium b) all light reflects back into the n2 medium c) part of the light reflects back into the n1 medium, the remainder travels along the boundary between the two mediums d) part of the light reflects back...
*July 31, 2014*

**Physics- check answer please**

Would the answer be b)? diamond into air? A critical angle of 24.4 degrees applies to: a) light travelling from air into diamond b) light travelling from diamond into air c) light travelling from water into diamond d) light travelling from diamond into water
*July 31, 2014*

**physics**

light travelling in air is incident on a soap bubble. If the path difference through the soap bubble is 2.5λ: a) constructive interference will occur b) destructive interference will occur c) partial interference will occur d) none of the above Would the answer be a?
*July 31, 2014*

**physics**

How would I figure out the answer to this question? A critical angle of 24.4 degrees applies to: a) light travelling from air into diamond b) light travelling from diamond into air c) light travelling from water into diamond d) light travelling from diamond into water
*July 31, 2014*

**Physics- check answer please**

light travelling in air is incident on a soap bubble. If the path difference through the soap bubble is 2.5λ: a) constructive interference will occur b) destructive interference will occur c) partial interference will occur d) none of the above Would the answer be a?
*July 30, 2014*

**physics**

light travelling in air is incident on a soap bubble. If the path difference through the soap bubble is 2.5λ: a) constructive interference will occur b) destructive interference will occur c) partial interference will occur d) none of the above
*July 30, 2014*

**physics**

light travelling in air is incident on a soap bubble. If the path difference through the soap bubble is 2.5λ: a) constructive interference will occur b) destructive interference will occur c) partial interference will occur d) none of the above
*July 29, 2014*

**Physics -- check answer please**

Light travelling in water is incident on air refracts at an angle of 27 degrees. What is the angle of incidence? my answer: 37 degrees
*July 29, 2014*

**Physics -- check answers please**

Light travelling in water is incident on air refracts at an angle of 27 degrees. What is the angle of incidence? my answer: 37 degrees
*July 28, 2014*

**physics**

1. If the period of a wave is 0.27s, how many waves would pass by in 1.0 minute? 2. When a wave from of light passes through an opening that's large compared to its wavelength, it: a) behaves as a single new point source b) produces a straight wave front, curved backwards ...
*July 28, 2014*

**Physics -- check answer please**

Refraction is: a) the way light behaves when it goes through a narrow opening b)the way teo light sources interact to produce interference patterns c) the absorption of one component of the electric field d) none of the above are correct my answer: d
*July 28, 2014*

**Physics -- check answers please**

1. If 31 waves pass by a point in 1.7 s, what's the frequency? my answer: 18.2 Hz 2. if a crest with an amplitude of 7cm interferes with a trough with an amplitude of 10 cm, the resulting wave has an amplitude of: my answer: -3
*July 28, 2014*

**statistics**

A researcher wishes to estimate the proportion of adults living in rural areas who own a gun. He wishes to achieve a margin of error of 2.8%. What is the minimum sample size needed?
*July 28, 2014*

**physics**

Red light with a wavelength of 660 nm and blue light with a wavelength of 480 nm are beamed at a double slit with a separation of 2x10^-3 mm. The third order maximums for the different colours occur at different spots. What is the angle between the second order maximums?
*July 27, 2014*

**Chemistry**

Why would you subtract the heat of a calorimeter when calculating heat of the reaction? hint: the heat of the calorimeter is the amount of heat that the calorimeter absorbs from the solution-each calorimeter will absorb a certain amount of heat, which means that the ...
*July 27, 2014*

**chemistry check answer**

Question: Explain whether using solid NaOH pellets rather than aqueous NaOH would alter the enthalpy. If different, would it be higher or lower My answer: Would the result be different since the aqueous NaOH would be able to quickly dissolve in water unlike solid NaOH which ...
*July 27, 2014*

**physics**

Fill in blank: Two slits can produce an interference pattern with visible light but this maximal point of constructive interference can be made more pronounced by using many fine lines in a __________
*July 27, 2014*

**physics**

Fill in blank Increasing the distance between a pair of slits through which light is being shone would ___ the distance between nodal lines appearing on a screen
*July 27, 2014*

**wavelength**

A human's wavelength is similar to the size of: a) a cell b) atom c) nucleus d) proton e) something else and why?
*July 26, 2014*

**Physics**

I am to fill in the blanks without a word bank, my answers are in brackets. 1. When light waves reflect from media in which the speed of light is slower, their phase (crest or trough) is ____ 2. The trick to being able to observe interference patterns for light waves in to ...
*July 26, 2014*

**Physics -- check answers please**

I am to fill in the blanks without a word bank, my answers are in brackets. 1. A ____ diffraction pattern is unique because it has a larger central maximum. (single slit) 2. the brightest, clearest diffraction pattern is created with a _____ (barrier)
*July 26, 2014*

**Physics**

The following figure represents the ride for a cart with a mass of 200 kg along a frictionless track. a. Calculate the velocity of the cart at points A, B, and C if the cart is dropped from a height of 100m with a initial velocity of 10 m/s. b. Calculate the height of the ...
*July 25, 2014*

**Chemistry**

I think that the question is saying why you do subtraction in the equation Qrxn=-Qcal-Qsoln
*July 22, 2014*

**Chemistry**

Why would you subtract the heat capacity of the calorimeter when calculating the heat of the reaction?
*July 22, 2014*

**Chemistry**

For the equation q=cΔt, q=100KJ, initial temp=20 degrees celsius, final temp=31.4 degrees celsius and I need to find c. Do I need to convert the q value from KJ to J?
*July 22, 2014*

**physics**

Fill in blank without a word bank (unit is wave nature of light) 1. As water waves travels through a slit barrier, they bend and spread out. This is known as ______ 2. Two identical waves will interfere destructively, cancelling one another out, when one lags behind the other ...
*July 21, 2014*

**Chemistry**

For an enthalpy lab, why would calculated value differ from the theoretical value (in percent error) for the heat reaction of Mg/HCl and MgO/HCl
*July 21, 2014*

**SOLVED**

I figured out this question
*July 21, 2014*

**Chemistry**

Find the enthalpy of combustion of magnesium using Hess' law given the following data (assume that exactly 100.0 mL of HCl was used in each trial and that HCl is in excess) Magnesium/HCl reaction: Grams of Mg= 0.244g Initial temp= 32.2 degrees celsius Final temp= 21.3 ...
*July 21, 2014*

**Chemistry**

No, the question only says Mg
*July 21, 2014*

**Chemistry**

why can't the enthalpy of magnesium be measured using a coffee cup calorimeter?
*July 21, 2014*

**chemistry**

It is ok to have a negative percent error? I got a negative value for the percent error of the enthalpy of the formation of methane gas
*July 20, 2014*

**Chemistry**

The combustion reaction of Mg +1/2 O2-->MgO produces a very bright white flame and high heat. Verify that the following reactions produce the same overall reaction: a) MgO+2HCl-->MgCl2+H2O b) Mg+2HCl-->MgCl2+H2 c) H2+1/2O2-->H2O ΔH°= -285.8 KJ/mol
*July 20, 2014*

**Chemistry**

I am to use this formula to find ΔH°f,methane: ΔH°comb=2ΔH°f,water+ΔH°f, carbon dioxide-ΔH°f,methane-2ΔH°f,oxygen For ΔH°comb, the value is 884 KJ/mol For ΔH°f,water, the value is -285.8 For ΔH°f,...
*July 20, 2014*

**Chemistry**

ok I got it now!
*July 20, 2014*

**Chemistry**

Ok thanks! I used PV=nRT to calculate the mols but I got a larger number. Here's what I did: P= 1.000 atm V= 0.271 L R= 0.08206 Latm/molK T= 2.3 K and I got 1.436 as my answer
*July 20, 2014*

**Chemistry**

A calorimeter is filled with 10.0 millimole (mmole) of methane gas and an excess of oxygen. When burned, the ignition wire releases 140.77 J of heat. The heat capacity of the calorimeter is 4.319 KJ°C-1. qwire= 140.77 J Calculate ΔHcomb. Recall that ideal gas law is ...
*July 20, 2014*

**Chemistry**

Ok I understand it now! Thank you so much!
*July 19, 2014*

**Chemistry**

Oh so answer would be 907 J/mol? also for the thermochemical equation you said it would be CH4 + 2O2 ==> CO2 + 2H2O with ΔH=- 890 kJ/mol but I don't know how to calculate that value
*July 19, 2014*

**Chemistry**

I have previously posted this question, but now I am lost question: A calorimeter is filled with 10.0 millimole (mmole) of methane gas and an excess of oxygen. When burned, the ignition wire releases 107.2 J of heat. The heat capacity of the calorimeter (including the bomb and...
*July 19, 2014*

**Chemistry**

I got 0.907 KJ for ΔHcomb but I don't know if its correct. I also don't know how to write the equation. -------- question: A calorimeter is filled with 10.0 mole of methane gas and an excess of oxygen. When burned, the ignition wire releases 107.2 J of heat. The ...
*July 16, 2014*

**Chemistry**

Yes the initial temperature is 24.75 degrees celsius and the final temperature is 26.85 degrees celsius
*July 16, 2014*

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