Tuesday

September 23, 2014

September 23, 2014

Total # Posts: 754

**Thermodynamics**

A lawnmower tractor engine produces 18hp using 40kW of heat transfer from burning fuel. Find the thermal efficiency and the rate of heat transfer rejected to the ambient. I converted the power to 13.24kW then found the efficiency by dividing 13.24kW by 40kW but the answer is ...
*June 12, 2013*

**Thermodynamics**

An empty cannister of 0.002 m3 is filled with R-134a from a line flowing saturated liquid R-134a at 0°C. The filling is done quickly so it is adiabatic, but after a while in storage, the can warms up to room temperature, 20degC. Find the final mass in the cannister and the...
*June 5, 2013*

**Chemistry DrBob222**

can you explain how to do t his i am confused
*May 29, 2013*

**Thermodynamics**

In a multiple-device flow system, I want to determine a state property. Where should I look for information, upstream or downstream?
*May 13, 2013*

**business calc**

The demand function for a certain brand of CD is given by p = −0.01x2 − 0.2x + 12 where p is the wholesale unit price in dollars and x is the quantity demanded each week, measured in units of a thousand. Determine the consumers' surplus if the market price is ...
*May 2, 2013*

**Thermodynamics**

Water in a piston/cylinder is at 100degC, x=0.5 with mass 1kg and the piston rests on two stops. The equilibrium pressure that will float the piston is 300 kPa. The water is heated to 300degC by an electrical heater. a) At what temperature would all the liquid be gone? I ...
*May 1, 2013*

**Enlish ARTS **

What is important as a last step in writing an essay?
*April 11, 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*

**AP Stats (math)**

A large metropolitan area found that the time it takes for people to commute to work has a mean of 20.5 minutes and a standard deviation of 15.4 minutes. What is the probability that a random sample of 40 people have a mean commute time greater than 25 minutes?
*April 7, 2013*

**Chemistry**

The elements lithium and oxygen react explosively to from lithium oxide (Li2O). How much lithium oxide will form if 3.03 mol of lithium react? Answer in units of mol
*April 4, 2013*

**Chemistry**

At 103◦C, the pressure of a sample of nitrogen is 1.89 atm. What will the pressure be at 275◦C, assuming constant volume? Answer in units of atm
*April 4, 2013*

**Chemistry**

How many grams do 5.8×10 24 atoms of argon weigh? Answer in units of g
*April 4, 2013*

**chemistry**

t 103 ◦ C, the pressure of a sample of nitrogen is 1 . 89 atm. What will the pressure be at 275 ◦ C, assuming constant volume? Answer in units of atm
*April 4, 2013*

**Math**

Use intermediate value theorem to show there is a root to 2x^3 + x^2 - 2 = 0 on [0,1]
*March 13, 2013*

**Physics**

An aluminum ring of radius 5.00 cm and resistance 2.00 10-4 Ω is placed around the top of a long air-core solenoid with 997 turns per meter and a smaller radius of 3.00 cm, as in the figure below. If the current in the solenoid is increasing at a constant rate of 267 A/s...
*March 12, 2013*

**Math**

A box contains a one-dollar bill, a five-dollar bill, a ten-dollar bill, and a twenty-dollar bill. Two bills are chosen in succession without replacement. 1. What is the probability that the value of at least one of the bills is even? As a fraction
*February 13, 2013*

**Math**

Scott can travel from Rochester, N.Y., to New York City by bus, train, car, or airplane. He can travel from New York to London, England, by airplane or ship. 1. How many choices for the trip from Rochester to London are there?
*February 13, 2013*

**Math**

A box contains a one-dollar bill, a five-dollar bill, a ten-dollar bill, and a twenty-dollar bill. Two bills are chosen in succession without replacement. Use a tree diagram to list the sample space for this experiment and then answer the following questions in fractions 1. ...
*February 8, 2013*

**Probability **

A nickel is flipped and a dime is flipped. 1. What is the probability of obtaining exactly one head? A bag contains five balls numbered 0 through 4. Two balls are chosen at random in succession. The first ball is replaced before the second is chosen. 1. What is the probability...
*February 7, 2013*

**Math **

A nickel is flipped and a dime is flipped. 1. What is the probability of obtaining exactly one head? A bag contains five balls numbered 0 through 4. Two balls are chosen at random in succession. The first ball is replaced before the second is chosen. 1. What is the probability...
*February 7, 2013*

**Chemistry**

Calculate the radius of a vanadium atom, given that V has a BCC crystal structure, a density of 5.96 g/cm3, and an atomic weight of 50.9 g/mol. I used this equation: density = (2)*(atomic weight) / (volume of unit cell)*(Avagodro's #) rearranged to find the volume of the ...
*January 16, 2013*

**Chemistry**

Calculate the radius of a vanadium atom, given that V has a BCC crystal structure, a density of 5.96 g/cm3, and an atomic weight of 50.9 g/mol. I used this equation: density = (2)*(atomic weight) / (volume of unit cell)*(Avagodro's #) rearranged to find the volume of the ...
*January 16, 2013*

**Chemistry**

The atomic number of an electrically neutral atom is equal to the number of: Choose all that apply. Neutrons Electrons Protons I chose Electrons but somehow my homework program is telling me it's wrong? I also tried checking all of them.
*January 13, 2013*

**Calculus**

How do you simplify: 5*e^(-10x) - 3*e^(-20x) = 2 I'm not sure if I can take natural log of both sides to bring down the exponents.
*January 11, 2013*

**Calculus**

Hm, I've never done integrals using that method before. I'll check it.
*January 9, 2013*

**Calculus**

How do you integrate: 1/(x^2-1) dx ?
*January 9, 2013*

**math**

oh, its d! thanks so much
*December 30, 2012*

**math**

if -1/7x - 6 = 34, find the value of -2x + 3 a) -280 b) -77 c) 395 d) 563 Can you pls explain it for me too
*December 30, 2012*

**algebra 1**

please help. Write a linear equation in slope-intercept from to model the situation. A telephone company charges $28.75 per mont plus .10 cent a minute for long distance calls
*December 20, 2012*

**math**

solve each inequalitiy y+ (-5) > -6
*December 4, 2012*

**math pls help Ms Sue**

could you pls check my math 6< s +7 -1<s -8.7<y + (-12.4) 21.1<y x + 17 > 10 -7 > x 11 > j + (-19) 30>j 24.3 > g- (-14.4) 38.7> g f + (-20) > -7 f > 30
*December 3, 2012*

**Physics**

I dont know
*December 2, 2012*

**physics **

A bird is ﬂying with a speed of 19.0 m/s over water when it accidentally drops a 2.50 kg ﬁsh. The acceleration of gravity is 9.81 m/s^2 If the altitude of the bird is 9.00 m and air resistance is disregarded, what is the speed of the ﬁsh when it hits the ...
*November 28, 2012*

**math pls help Ms Sue**

Find the rule for the function table m n 15 12 10 8 5 4 0 0
*November 27, 2012*

**math**

Find the rule for each function table m n 15 12 10 8 5 4 0 0
*November 27, 2012*

**Physics. Error equations. Please help!**

These two equations concern a lab on the measurement of E/M by the Brainbridge Method. I need to derive the absolute error for two different equations, the first one is: e/m = 2V/B2R2 treat (e/m) as a SINGLE VARIABLE when doing the derivation. The second is B=8μ0N(I-Io...
*November 20, 2012*

**Physics**

In a very busy off-campus eatery one chef sends a 241-g broccoli-tomato-pickle-onion-mushroom pizza sliding down the counter from left to right at 1.53 m/s. Almost simultaneously, the other chef launches a 321-g veggieburger-on-a-bun (with everything, but hold the horseradish...
*November 19, 2012*

**Physics**

During a neighborhood baseball game in a vacant lot, a particularly wild hit sends a 148-g baseball crashing through the pane of a second-floor window in a nearby building. The ball strikes the glass at 10.1 m/s, shatters the glass as it passes through, and leaves the window ...
*November 19, 2012*

**Physics**

In a very busy off-campus eatery one chef sends a 241-g broccoli-tomato-pickle-onion-mushroom pizza sliding down the counter from left to right at 1.53 m/s. Almost simultaneously, the other chef launches a 321-g veggieburger-on-a-bun (with everything, but hold the horseradish...
*November 19, 2012*

**Physics**

An open train car, with a mass of 2150 kg, coasts along a horizontal track at the speed 2.29 m/s. The car passes under a loading chute and, as it does so, gravel falls vertically into it for 2.67 s at the rate of 441 kg/s. What is the car's speed after the loading is ...
*November 19, 2012*

**Physics**

A 70.0 kg football player leaps straight up into the air (with no horizontal velocity) to catch a pass. He catches the 0.430 kg ball precisely at the peak of his jump, when he is 19.2 inches off the ground. He hits the ground 1.61 inches away from where he leapt. If the ball ...
*November 19, 2012*

**Physics**

During a neighborhood baseball game in a vacant lot, a particularly wild hit sends a 148-g baseball crashing through the pane of a second-floor window in a nearby building. The ball strikes the glass at 10.1 m/s, shatters the glass as it passes through, and leaves the window ...
*November 19, 2012*

**Physics**

An unfortunate astronaut loses his grip during a spacewalk and finds himself floating away from the space station, carrying only a rope and a bag of tools. First he tries to throw a rope to his fellow astronaut, but the rope is too short. In a last ditch effort, the astronaut ...
*November 19, 2012*

**Physics. Please please help!**

Shouldn't the answer be 1.62*10^4V? Unless i'm putting the numbers in wrong. Please help
*November 14, 2012*

**Physics. Please please help!**

A charge Q = +4.5 uC is located at the origin and is fixed so that it cannot move. A small object with mass m = 2.0 g and charge q = +8.0 uC is released from rest at point A on the x-axis at x = 2.0 cm. The small object moves without friction along the x-axis under the ...
*November 14, 2012*

**calculus**

A five feet piece of wire is cut into two pieces. One Piece is bent into a square and the other is bent into an equilateral triangle. Where should the wire be cut so that the total area enclosed by both is minimum.
*November 14, 2012*

**Physics**

"You will measure the tension T, the mass m, and the length L of your spring. In terms of these variables, what is the expected frequency of the fundamental standing wave?" I found the fundamental frequency to be: f = 1/2L * sqrt(T/m/L)?
*October 31, 2012*

**Math**

write an algebraic expression then evaluate, given n=2 5 less than the quotient of -10 and a number is the answer (-10 / 2) - 5 = 0
*October 30, 2012*

**Physics**

"A slinky that satisfies v = sqrt(T/_mu) is stretched 12m. The mass of the slinky is 0.8kg. The tension on the slinky is 4N. What is the expected wave speed?" To get mu, I divided the mass by the length then plugged that into the equal and solved for v but I'm ...
*October 30, 2012*

**math**

260 divided by 10=26 does (260 divided by 10)x5=26x5
*October 29, 2012*

**calculus (math)**

Simplify exactly log_2 1/16
*October 27, 2012*

**math**

how could you use the product of 108 and 4 to find the product of 324 and 4?
*October 24, 2012*

**math**

an airplaine has an altitude of 20,000 feet. it climbs another 5,000 feet to avoid a storm. What integer expresses the position of the airplane compared to ground level?
*October 24, 2012*

**math**

-4 - (-8) = I got 4 is this correct -2 - (-6) = Again I got 4 is this also correct
*October 23, 2012*

**PHYSICS H**

suppose an elephant and a feather fall from a skyscraper. in the presence of air resistance, the elephant would fall faster because...list all that apply. a) acceleration of gravity is greatest for the elephant b) elephant experiences a smaller air resis. force c) the greater ...
*October 23, 2012*

**Physics**

Why is it necessary to collimate the light source before using the prism to disperse the light? A. If white light enters the prism with different angles, some of the blue light will exit the prism with the same angle as the orange light. B. If white light enters the prism with...
*October 22, 2012*

**math**

A spiiner was spun 16 times. The results are shown in the table below. yellow = 5 white = 4 red = 0 blue = 2 green = 2 orange = 3 whch colors' experimental probability matches its theoretical probability a. yellow, green and orange b. white, red and orange c. yellow, blue ...
*October 21, 2012*

**engineering**

A string is fit snugly around the circumference of a spherical hot air balloon. More hot air is added (probably by a prominent scientist’s lecture) and it now takes an additional 12.4 feet of string to fit around the circumference. What is the increase in diameter?
*October 17, 2012*

**Math. Have answer, please show work**

In a tracer method the potassium isotope 42K is used for labelling. The half life of 42K is 12.5 hours. If No is original number of atoms, how many hours will it take until only (1/1024) No Atoms remain? The answer is 125 hours but I do not know how to get this. Please help!
*October 13, 2012*

**math. solve for t**

im getting 104 hours but the correct answer is 125 hours?
*October 13, 2012*

**math. solve for t**

1/1024=42*0.5^(t/12.5) Solve for t. Please show work. Much appreciated!
*October 13, 2012*

**Math**

u-2√u=3. what is u?
*October 13, 2012*

**Chemistry**

The molar enthalpy of combustion of glucose is -2803 kJ. A mass of 1.000 g glucose is combusted in a bomb calorimeter. If the calorimeter contains 875 g H2O and the bomb has a heat capacity of 457 J/C, what is the temperature increase of the bomb calorimeter? the specific heat...
*October 11, 2012*

**Chemistry**

The molar enthalpy of combustion of glucose is -2803 kJ. A mass of 1.000 g glucose is combusted in a bomb calorimeter. If the calorimeter contains 875 g H2O and the bomb has a heat capacity of 457 J/C, what is the temperature increase of the bomb calorimeter? the specific heat...
*October 11, 2012*

**Chemistry**

The molar enthalpy of combustion of glucose is -2803 kJ. A mass of 1.000 g glucose is combusted in a bomb calorimeter. If the calorimeter contains 875 g H2O and the bomb has a heat capacity of 457 J/C, what is the temperature increase of the bomb calorimeter? the specific heat...
*October 11, 2012*

**logic**

The sentence "P → Q" is read as
*October 7, 2012*

**CHEMISTRY! HELP!**

I have a hard time getting this someone help me? Astronauts often use the unit light year to express intergalactic distances. If light travels 3.00 x .10^10 cm/s and one year is defined as 365 days, how many kilometers does light travel in one year?
*October 6, 2012*

**Math**

Explain in words, how you would solve: 3(n-8) = 12 + 2n
*October 4, 2012*

**physics/math**

If you are driving 116 km/h along a straight road and you look to the side for 3.0 s, how far do you travel during this inattentive period?
*October 1, 2012*

**Math. due tomorrow**

A female moth lays nearly 150 eggs. In on year there may live up to five generations. Each larva eats about 20mg of wool. Assume that 2/3 of the eggs die and that 50% of the remaining moths are females. Estimate the amount of wool that may be destroyed b the descendants of one...
*October 1, 2012*

**Reading**

Is the book KICKOFF! by Tiki & Ronde Barber with Paul Mantell Fiction or non-fiction?
*September 24, 2012*

**math**

we got 119 3/20 for the perimeter
*September 20, 2012*

**math**

the dims are of the poster and then he adds 4 1/2 inch
*September 20, 2012*

**math**

a poster reproduces the Mona Lisa in the original size, but adds a 4 1/2 inch border around each side. What is the perimeter of this poster if the length is 30 3/10" and width is 20 7/8"?
*September 20, 2012*

**math**

anoter poster reproduces the Mona Lisa in the original size, but adds a 4 1/2 inch border around each side. What is the perimeter of this poster if the length is 30 3/10" and width is 20 7/8"?
*September 20, 2012*

**Math**

In 45 seconds. 9,18,27,36.45 15,30,45
*September 18, 2012*

**math**

I thought I needed to do 9/10 x 7/1 which is 63/10 = 6 3/10
*September 18, 2012*

**math**

thank you
*September 18, 2012*

**math**

when planting trees in a forest, the US Forest Service recommends giving each seedling about 1/200 acre on which to grow. About hw many seedling should be planted in 1/3 of an acre? How would I show my work on this? would it be 1/3 x 200/1 = ?
*September 18, 2012*

**math**

Thank you!
*September 17, 2012*

**math**

still stuck on this one please help Marissa plans to use 50 sheet of aper for a scrapbook. How much thicker will the scrapbook be if she uses heavyweight (which is 2/5 in for 100 sheets) instead of lightweight paper (which is 3/10 in for 100 sheets)?
*September 17, 2012*

**math**

I do understand that, but if he uses 1/4 of the paper for the english section and 1/3 of the paper of the other 3/4 for the math section. How would I show this.
*September 17, 2012*

**math**

Eddie buys 100 sheets of heavyweight paper to make a notebook. He places 1/4 of the sheets in a section for English and 1/3 of the reamining sheets in a section for math. Which section is thicker if the 100 sheets of heavyweight paper is 2/5 in per 100 sheets?
*September 17, 2012*

**math**

Juan's class has 10 girls and 15 boys. the ratio fo girl to boys in Steven's class is the same as the ratio of girl to boys in Juan's class.How many girls are in Steven's class. Picture/diagram of my composed solution. We know that the ratio is 1:1.5 with a ...
*September 12, 2012*

**math word problem**

Weds to Thurs
*September 10, 2012*

**Biology**

How are radioisotopes used to make biochemical reactions?
*September 8, 2012*

**math**

Two trains are traveling the same direction, train a is going 60 mph and train b is going 70 mph, after one hour how long will it take train a to reach the point train b was at the hour marker.
*September 2, 2012*

**math**

unit rate for 30 miles on 1.5 gal not sure how to write it
*August 29, 2012*

**math**

what is the unit rate $16 for 32 photos is it 16/32= .50/1
*August 29, 2012*

**math**

list all prime numbers under 20 and the find GCF for 62 and 80 using factoriztion. is the answer 2 x 2 =4
*August 15, 2012*

**math**

list all prime under 20. then find the GCF for 64 and 80 use prime factorization.
*August 15, 2012*

**Chemistry**

They did the right work but the answer is 40 grams. That is what it says in the book.
*August 10, 2012*

**math**

Ms Sue when you said 25 in the overlapping section of math and english did mean math and history/
*August 6, 2012*

**math**

need to make a venn diagram using 3 circles. A survey on subject being taken by 250 students at a certain college revealed the following info: 1. 90 were taking math 2. 145 were taking history 3. 88 were taking english 4. 25 were taking math and history 5. 38 were taking ...
*August 6, 2012*

**Math**

If I have cards numbered 1 through 40 and I randomly draw 3 then replace them, shuffle them and draw three again what are the odds of drawing one of the numbers more than once
*July 31, 2012*

**physics**

A vertically hanging spring has a mass of 50 N hanging from it. Under these conditions, the spring stretches 10 cm. The spring is then placed on a horizontal table and stretched 20 cm. What force is required in the second scenario?
*July 18, 2012*

**Principles of Management - Strategic Management**

1.d,2.b,3.c,4.a,5.a,6.c,7.a,8.d,9.b,10.b,11.c,12.b,13.c,14.a,15.b,16.b,17.d,18.c,19.d,20.b I did miss one but not sure which one it was.
*July 10, 2012*

**us history grade 7**

what are the pros and cons of the fur trade?
*June 21, 2012*

**Physics**

"A person is playing a small flute 10.75 cm long, open at one end and closed at the other, near a taut string having a fundamental frequency of 600.0 Hz. If the speed of sound is 344.0 m / s, for which harmonics of the flute will the string resonate? In each case, which ...
*June 4, 2012*

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