Friday

November 28, 2014

November 28, 2014

Total # Posts: 781

**Astronomy**

A simple temperature model for the solar nebula disk is ￼Tdisk(a) = 20 � SQRT 100 AU/ a K, (1) where a should be expressed in AU in this equation. ￼(a) Find the temperature in the solar nebula disk at the orbit of Mer- cury, Earth and Jupiter. (b) Where is...
*November 13, 2014*

**Science Physics**

How many Btu of heat must be added to 1200 lb of copper to raise its temperature from 100°F to 450°F -specific heat for copper is 0.092-
*November 4, 2014*

**Specific Heat**

Forgot to add specific heat for copper is 0.092
*November 3, 2014*

**Specific Heat**

How many Btu of heat must be added to 1200 lb of copper to raise its temperature from 100°F to 450°F
*November 3, 2014*

**Science Physics**

How many Btu of heat must be added to 1200 lb of copper to raise its temperature from 100°F to 450°F
*November 3, 2014*

**Physics (heat)**

A coal sample yields 1.25 X 10^4 Btu/lb. How many foot-pounds of work result from burning 1.00 ton of this coal?
*November 3, 2014*

**Science Physics**

600/9800
*November 3, 2014*

**Science Physics**

A lifeguard swims with her head just above the water. What is the volume of the submerged part of her body if she weighs 600 N? Would I need to divide by 9800 or 62.4?
*November 3, 2014*

**Science Physics**

A flat-bottom river barge is 30.0 ft wide, 85.0 ft long, and 15.0 ft deep. (a) How many ft3 of water will it displace while the top stays 3.00 ft above the water? (b) What load in tons will the barge contain under these conditions if the empty barge weighs 160 tons in dry dock?
*October 31, 2014*

**physics**

Bob, who has a mass of 80kg , can throw a 550g rock with a speed of 27m/s . The distance through which his hand moves as he accelerates the rock forward from rest until he releases it is 1.0 m. What constant force must Bob exert on the rock to throw it with this speed? If Bob ...
*October 30, 2014*

**Fluid Mechanics Physics**

A flat-bottom river barge is 30.0 ft wide, 85.0 ft long, and 15.0 ft deep. (a) How many ft3 of water will it displace while the top stays 3.00 ft above the water? (b) What load in tons will the barge contain under these conditions if the empty barge weighs 160 tons in dry dock?
*October 29, 2014*

**Hydraulic Physics**

thank you
*October 29, 2014*

**Hydraulic Physics**

So it would be 50.0/25.0*20.0=40
*October 29, 2014*

**Hydraulic Physics**

In a hydraulic system a 20.0-N force is applied to the small piston with cross sectional area 25.0 cm2. What weight can be lifted by the large piston with cross sectional area 50.0 cm2? Would I need to divide both pistons areas then mutiply the force? and or have gravity in ...
*October 29, 2014*

**Fluid Mechanics**

A flat-bottom river barge is 30.0 ft wide, 85.0 ft long, and 15.0 ft deep. (a) How many ft3 of water will it displace while the top stays 3.00 ft above the water? (b) What load in tons will the barge contain under these conditions if the empty barge weighs 160 tons in dry dock?
*October 29, 2014*

**Fluid Mechanics**

In a hydraulic system a 20.0-N force is applied to the small piston with cross sectional area 25.0 cm2. What weight can be lifted by the large piston with cross sectional area 50.0 cm2?
*October 29, 2014*

**MATH (PROBABILITY) **

According to Nielsen Media Research, approximately 52% of all U.S. households have digital cable television. In addition, 84% of all U.S. households have multiple TV sets. Suppose 45% of all U.S. households have digital cable television and have multiple TV sets. A U.S. ...
*October 10, 2014*

**Chem 30 Thermodynamics **

Your friend comes across a good deal to purchase a gold ring. She asks you for advice for you to test the ring. The ring has a mass of 4.54 g. When you heat the ring with 94.8 J of energy, its temperature rises from 23.0 degrees celsius to 47.5 degrees celsius. Would you ...
*October 9, 2014*

**physics**

Suppose that 1100 j of work is done by the force 30 n in moving the suitcase a distance of 50 m. At what angle is the force oriented with respect to the ground?
*October 8, 2014*

**Physics (Force)**

A power wheelbarrow has a mass of 432 kg. What force must be applied to give it an acceleration of 1.75 m/s2?
*September 30, 2014*

**FRACTION CONCEPTS**

I am a fraction whose numerator and denominator are both prime numbers less than 20. if you were to increase each term by 1, I would be equivalent to 1/2. what fraction am I?
*September 23, 2014*

**Physics**

A relativistic proton has a momentum of 1.0×10^-17 kg ∙ m/s and a rest energy of 0.15 nJ. What is the kinetic energy of this proton? (c = 3.00 × 108 m/s, mass of proton = 1.67 × 10-27 kg)
*September 20, 2014*

**Physics**

Assume that a certain city consumes electrical energy at an average rate of 2.0× 10^9 W. What would be the mass change in producing enough energy to keep this city running for 21 weeks?
*September 20, 2014*

**math/stats**

What is the standard deviation of a $1 bet on any one particular number, e.g., 33, in the game of American roulette? Notice the payoff is 35:1 for this type of bet.
*September 2, 2014*

**statistics**

What is the standard deviation of a $1 bet on any one particular number, e.g., 33, in the game of American roulette? Notice the payoff is 35:1 for this type of bet.
*September 2, 2014*

**physics **

how long does it take an car travailing in the left lane of a highway at 60km/h to overtake another car in the right lane traveling at 40km/hr when the cars start 100meters apart
*July 27, 2014*

**geometry**

one side of a parallelogram has endpoints (2,1) and (3,5) The endpoints for the opposite side are (5,2) and (6,6) true or false
*July 16, 2014*

**AP chemistry**

42.1 degrees celsius
*May 20, 2014*

**geography**

what is the value of igneous rocks to humankind?
*April 21, 2014*

**math**

The garage you work for as an auto mechanic measures 230 ft. by 150 ft and handles 69 cars. Using the existing garage as a model, how much space would you plan to have in your garage?
*April 19, 2014*

**math**

You require space to service 65 vehicles at any one time. Will a facility measuring 145 ft. by 130 ft. be adequate if each vehicle requires 300 sq.ft.?
*April 15, 2014*

**math**

Hal Fritz purchased a $5,000 bond at 95. The annual interest is 6%.What was the cost of the bond? What was the annual interest? What is the yield (to nearest tenth of a percent)? please help
*April 12, 2014*

**Chemistry**

Are my answers correct? Identify each energy exchange as primarily heat or work and determine weather the sign of ?E is positive or negative for the system. A. A rolling billiard ball collides with another billiard ball. The first ball (system) stops rolling after the ...
*April 9, 2014*

**math**

Thanks :)
*April 8, 2014*

**math**

So it's 40%?
*April 8, 2014*

**math**

What % of $3.75 is $1.50?
*April 8, 2014*

**math**

Brendan got 31 questions correct on his social studies test and missed 9 questions. What percent did he have correct?
*April 8, 2014*

**math**

If Sue worked 6 3/4 hours on Monday, 4 hours on Tuesday, 7 3/4 hours on Wednesday, 8 hours on Thursday, and 5 1/2 hours on Friday, calculate her weekly wage at $7.20 per hour.
*April 8, 2014*

**math**

Frank owns 300 acres of land. If he divides the land into 1/2 acre plots, how many plots will he have?
*April 8, 2014*

**chemistry**

Are my answers correct? Identify each energy exchange as primarily heat or work and determine weather the sign of ΔE is positive or negative for the system. A. A rolling billiard ball collides with another billiard ball. The first ball (system) stops rolling after the ...
*April 8, 2014*

**chemistry**

Are my answers correct? Identify each energy exchange as primarily heat or work and determine weather the sign of ΔE is positive or negative for the system. A. A rolling billiard ball collides with another billiard ball. The first ball (system) stops rolling after the ...
*April 8, 2014*

**math**

.An angle is 10° more than the measure of its complement. Find the number of degrees in each angle.The angles measure _ degrees.
*April 6, 2014*

**math**

An alloy of copper is 10% copper and weighs 25 pounds. A second alloy is 18% copper. How much (to the nearest tenth lb.) of the second alloy must be added to the first alloy to get a 13% mixture.
*April 6, 2014*

**math**

Two angles are complementary. One contains 30° more than the other. Find both angles. The measures of the angles are _ degrees
*April 5, 2014*

**math**

If the angle of declination is known, a surveyor would use_______ to find the length x. The cosine of a 50° angle is_______ this represents the value created when length x is divided by 90 feet. If the angle of declination changed to 60°, the cosine would be 0.5; now ...
*April 5, 2014*

**math**

The Smiths want to buy a 9 ft. by 12 ft. carpet and center it in a 15 ft. by 20 ft. room. Can a 3 1/2 foot by 12 foot couch be placed against one of the long walls of the room without touching the carpet?
*April 4, 2014*

**Chemistry**

please help me balance these equations using the method of half reactions.. Na + HCL = NaCl + H2 Pb + PbO2 + H2SO4 = PbSO4 +H2O Thank you, even a little help is appreciated.
*April 2, 2014*

**Biology**

Exogenous treatment with the plant hormone, ABA or auxin, induces enhanced susceptibility against biotrophic pathogens. Design an experiment that can reveal whether these hormones use the same signalling pathway or independent pathways to induce susceptibility.
*March 21, 2014*

**English**

In "Paul's Case," members of the faculty don't like Paul's carnation because they think A. it doesn't match his other clothing. B. it suggests that he's not taking things seriously. C. it's the mark of an early death. D. it's effeminate ...
*February 26, 2014*

**physics**

A)A model rocket is launched straight upward with an initial speed of 47.7 m/s. It accelerates with a constant upward acceleration of 2.02 m/s2 until its engines stop at an altitude of 157 m. What is the maximum height reached by the rocket? B)How long after lift off does the ...
*January 25, 2014*

**economics**

you find out that your aunt works for a defense manufacturing company that has several defense contracts with the government. she tells you that she works for a team that is producing a communications satelluite
*January 21, 2014*

**Math**

Thank you
*January 16, 2014*

**Math**

Find four ratios equivalent to 30%
*January 16, 2014*

**world history**

What was the goal of Americanization programs in settlement houses?
*January 14, 2014*

**Lang Arts**

A Retrieved Reformation By: O. Henry
*January 10, 2014*

**Lang Arts**

2. What do you learn about Ben price's character from his actions at the end of they story a. He is a determined man who will stop at nothing to catch Jimmy b. He is a forgiving man who is willing to let jimmy go c. He is a jealous man who wants Annabel for himself d. He ...
*January 10, 2014*

**math**

find the area under the normal distribution curve to the right of z = -2.40
*December 7, 2013*

**math**

find the area under the normal distribution curve between z = -1.25 and z = 2.20
*December 7, 2013*

**Stats**

If a student's rank in a class of 300 students is 111, find the student's percentile rank
*December 7, 2013*

**Physics**

A 153 g bullet is fired from a rifle having a barrel 0.794 m long. Assuming the origin is placed where the bullet begins to move, the force exerted on the bullet by the expanding gas is F = a + bx − cx^2 , where a = 12600 N, b = 8420 N/m, c = 10100 N/m^2, with x in ...
*November 18, 2013*

**Physics**

I figured it out. The answer is 10973.29 J. You just jsd2272 your x values mixed up. Thanks for the equation though. :)
*November 15, 2013*

**Physics**

That answer was wrong :(
*November 15, 2013*

**Physics**

So f = (9.8)(153) and d=.794? And then do I solve for x? How would I solve for x? ( never taken calculus)
*November 15, 2013*

**Physics**

A 153 g bullet is fired from a rifle having a barrel 0 . 794 m long. Assuming the origin is placed where the bullet begins to move, the force exerted on the bullet by the expanding gas is F = a + bx − cx 2 , where a = 12600 N, b = 8420 N / m, c = 10100 N / m 2 , with x ...
*November 15, 2013*

**Stats **

According to a Louis Harris poll, 63% of male drivers always use seat belts. A recent sample of 900 male drivers showed that 60% of them always use seat belts. Test at the 0.01 lovel of significance if the proportion of male drivers who always use seat belts is less than .63.
*November 14, 2013*

**Phyics**

One of the concrete pillars that supports a house is 1.9 m tall and has a radius of 0.55 m. The density of concrete is about 2.2 x 103 kg/m3. Find the weight of this pillar in pounds (1 N = 0.2248 lb).
*November 12, 2013*

**science**

1 what would cause a plant to have a shorter day. 2 what would cause a plant to have a longer day
*October 20, 2013*

**math**

-233 + (-233) = 0 ? is this corect? Thank You
*October 14, 2013*

**mathematics**

Which number is equivalent to 0.00000001: 10 to the seventh power or 10 to the negative seventh power? How do you know?
*September 26, 2013*

**Chemistry**

which is more accurate direct weighting or weighing by difference?
*September 24, 2013*

**history**

what is a good website to describe a boom town in the west in the 1800s. a website of what they do there and what occurs during a typical day of mining.. including techniques of mining, description of the town, the mines, and the town's inhabitants... also efforts to ...
*September 23, 2013*

**history**

thank you :)
*September 23, 2013*

**history**

use ten adjectives to describe ghost towns. I got: 1-abandoned 2-ancient 3-lonely 4-broken down 5-old 6-empty 7-sad 8-quiet I still need 2 more adjectives, but I am all out of ideas.. please help, thank you
*September 23, 2013*

**social studies (history)**

yes they do
*September 23, 2013*

**social studies (history)**

well clique means a small group of people, with shared interests or other features in common, who spend time together and do not readily allow others to join them.. so wouldn't it be that vigilant justice is similar to cliques in middle school because vigilante justice ...
*September 23, 2013*

**Calculus**

Your Porsche's gas mileage (in miles per gallon) is given as a function M(x) of speed x in miles per hour. It is found that M'(x) = 3,600x−2 − 1/ (3,600x−1 + x)2. Estimate M'(10), M'(60), and M'(90). (Round your answers to seven decimal ...
*September 17, 2013*

**Calculus**

ok, maybe this is more accurate... M'(x) = (3600x^-2 -1)/ (3600x^-1 +x)^2
*September 17, 2013*

**Calculus**

Your Porsche's gas mileage (in miles per gallon) is given as a function M(x) of speed x in miles per hour. It is found that M'(x) = 3,600x−2 − 1/ (3,600x−1 + x)2. Estimate M'(10), M'(60), and M'(90). (Round your answers to seven decimal ...
*September 17, 2013*

**physics**

(a) What is the hot resistance of a 24 W light bulb that runs on 120 V AC? (b) If the bulb's operating temperature is 2700°C, what is its resistance at 2570°C?
*September 15, 2013*

**physics**

(a) What is the hot resistance of a 24 W light bulb that runs on 120 V AC? (b) If the bulb's operating temperature is 2700°C, what is its resistance at 2570°C?
*September 15, 2013*

**physics**

As part of a class project you are given 0.900 g of nichrome and asked to fabricate a wire with uniform cross-section. You use up 95% of the nichrome and make a wire with a resistance of 0.840 Ω. The resistivity of nichrome is 1.00 10-6 Ω · m and its density ...
*September 15, 2013*

**physics**

Assuming 95.0% efficiency for the conversion of electrical power by the motor, what current must the 12.0 V batteries of a 740 kg electric car be able to supply: (a) To accelerate from rest to 25.0 m/s in 1.00 min? (b) To climb a 200 m high hill in 2.00 min at a constant 25.0 ...
*September 15, 2013*

**physics**

Assuming 95.0% efficiency for the conversion of electrical power by the motor, what current must the 12.0 V batteries of a 740 kg electric car be able to supply: (a) To accelerate from rest to 25.0 m/s in 1.00 min? (b) To climb a 200 m high hill in 2.00 min at a constant 25.0 ...
*September 15, 2013*

**physics**

I got the solution: copper=3.9x10^-3 iron=5.0x10^-3 R(1+α∆T)=R(1+α∆T) 0.425(1+0.0039∆T)=0.455(1+0.005∆T) ∆T=-48.6°C T=20°C-48.6°C=-28.6°C
*September 15, 2013*

**physics**

A copper wire has a resistance of 0.425 at 20.0°C, and an iron wire has a resistance of 0.455 at the same temperature. At what temperature are their resistances equal?
*September 15, 2013*

**physics**

A copper wire has a diameter of 1.532 mm. What magnitude current flows when the drift velocity is 0.500 mm/s?
*September 14, 2013*

**physics**

If an electron travels 0.150 m from an electron gun to a TV screen in 19.0 ns, what voltage was used to accelerate it? (Note that the voltage you obtain here is lower than actually used in TVs to avoid the necessity of relativistic corrections.)
*September 14, 2013*

**Physics**

If an electron travels 0.150 m from an electron gun to a TV screen in 19.0 ns, what voltage was used to accelerate it? (Note that the voltage you obtain here is lower than actually used in TVs to avoid the necessity of relativistic corrections.)
*September 13, 2013*

**History**

can you put in a sentence the words to make an offering Hapi (NIle) Osiris Wheat Growth Man Rejoice This is the only problem I need thanks :)
*September 9, 2013*

**Physics**

A, B, D, and F
*September 6, 2013*

**physics**

What is the force on the charge located at x = +8.00 cm. q = 1.00 µC and a = 8.00? (The positive direction is to the right.)
*August 27, 2013*

**physics**

Bees often work together for the greater good of the hive. Sometimes they can get excess charge on them. Four pairs of bees, which can be represented as identical, conducting spheres, bump into each other in the hive. Rank the bees in the order of the size of the magnitude of ...
*August 27, 2013*

**physics**

(a) Two point charges totaling 8.50 µC exert a repulsive force of 0.100 N on one another when separated by 0.839 m. What is the charge on each? smallest charge (µC) largest charge (µC) (b) What is the charge on each if the force is attractive? smallest charge...
*August 26, 2013*

**physics**

A 45.0 g ball of copper has a net charge of 1.5 µC. What fraction of the copper's electrons have been removed? (Each copper atom has 29 protons, and copper has an atomic mass of 63.5.)
*August 26, 2013*

**physics**

(a) Two point charges totaling 8.50 µC exert a repulsive force of 0.100 N on one another when separated by 0.839 m. What is the charge on each? smallest charge (µC) largest charge (µC) (b) What is the charge on each if the force is attractive? smallest charge...
*August 24, 2013*

**physics**

Two point charges exert a 2.50 N force on each other. What will the force become if the distance between them is increased by a factor of 5?
*August 24, 2013*

**physics**

What is the repulsive force between two pith balls that are 12.0 cm apart and have equal charges of -39.0 nC?
*August 24, 2013*

**physics**

A 45.0 g ball of copper has a net charge of 1.5 µC. What fraction of the copper's electrons have been removed? (Each copper atom has 29 protons, and copper has an atomic mass of 63.5.)
*August 24, 2013*

**physics**

How many coulombs of positive charge are there in 8.70 kg of plutonium, given its atomic mass is 244 and that each plutonium atom has 94 protons?
*August 24, 2013*

**physics**

How many coulombs of positive charge are there in 8.70 kg of plutonium, given its atomic mass is 244 and that each plutonium atom has 94 protons?
*August 21, 2013*

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