Friday

February 27, 2015

February 27, 2015

Total # Posts: 566

**Electricity and magnetism**

Thank you for your help. I am not sure what you mean by k.
*February 23, 2015*

**Electricity and magnetism**

A carbon atom's nucleus and its electrons become separated by 20nm. How much work does it take to separate them in Joules? In the previous problem if found that the magnitude of the force the nucleus feels towards the electrons is 2.07*10^11N. My first attempt was W=F*d = ...
*February 23, 2015*

**PHYSICS Electricity**

Maurice, I am having trouble too.
*February 19, 2015*

**Social Studies**

just to let you know i don't want the straight answer just an explanation
*February 18, 2015*

**Social Studies**

I am having trouble under standing these questions can someone please help? 11. What resources led to the appearance of the Industrial Revolution in New England? (5 points) 12. During the early 1800s, the United States tried to make peace with other countries in order to grow ...
*February 18, 2015*

**Chemistry**

What happens when sulphur reacts with iron? Does it make any colours before it turns dark grey? Does it do anything significant that I should need to know? I know that it is an exothermic reaction but is that it? Please help, Thanks.
*February 12, 2015*

**chemistry**

A moon rock collected by a U.S. Apollo mission is estimated to be 4.50 billion years old by uranium/lead dating. Assuming that the rock did not contain any lead when it was formed, what is the current mass of 206Pb per 1.150 g of 238U in the rock? The half-life of 238U is t1/2...
*February 11, 2015*

**Chemistry**

The average concentration of chloride ions (molar mass = 34.353) in seawater is 19.353 grams per kilogram. The maximum allowable concentration of chloride ion in drinking water is 250 ppm by mass. How many times as much chloride ion is there in seawater than the maximum amount...
*January 22, 2015*

**Math**

The container is coated with 2 layers of specialty paint that costs $6.05 per jar. Each jar of paint covers 800cm^2. How much does the paint cost?
*January 21, 2015*

**Intermediate algebra**

I need to simplify this rational expression and show the steps, please help.
*January 11, 2015*

**Math**

Find the value of csc theta for angle theta in standard position if the point at (5,-2) lies on its terminal side.
*January 8, 2015*

**math**

Graph f(x)=|x|^3
*January 8, 2015*

**English**

What genres, subjects, themes, settings, and characters has Mark Twain developed
*January 7, 2015*

**Math**

1) A car is traveling at a rate of 70 miles per hour. what is this speed in feet per minute. 2) Nina can braid 28 inches of rope in 1 hour. What is her speed in feet per hour? I am studying but I don't understand these questions. I have test tomorrow. Thank you.
*December 14, 2014*

**Math**

thank you very much
*December 9, 2014*

**Math**

thank you. please can you tell me how do you get 14 and 6 please. I want to understand. Thank you
*December 9, 2014*

**Math**

The price of a gallon of gasoline increased by 5 cents one week, decreased by 3 cents each of the next two weeks, and increased by 9 cents the fourth week. Find the average change in the price of gasolina for the 4 weeks.
*December 9, 2014*

**English**

Thank you!
*October 26, 2014*

**English**

Hi, I was wondering if this sentence has a comma splice? Before they get cold, grab that fluffy and heated towel, and dry them. Thanks in advance!
*October 26, 2014*

**Algebra 2**

what is an equation for the vertical translation of y=2x-1: 3/5 units up f) y=2x-2/5 g) y=2x-1/5 h) y=2x-8/5 I) y=2x+1/5
*September 16, 2014*

**Algebra 2**

what is an equation for each vertical translation of y=2x-1: 3/5 units up f) y=2x-2/5 g) y=2x-1/5 h) y=2x-8/5 I) y=2x+1/5
*September 16, 2014*

**Algebra 2**

how did you get 630km
*August 30, 2014*

**Algebra 2**

at 2 pm a freight train leaves a station and travels at 42 km/h. at 11pm and express train leaves the same station on a parallel track and travels at 105 km/h in the same direction. how far from the station will they meet?
*August 30, 2014*

**geometry**

in the proportion 2/8=8/32, which numbers is the geometric mean of the other two numbers?
*June 17, 2014*

**Physics**

A 0.2kg ball is attached to a rope and is whirled in a horizontal circle. Calculate the maximum speed of the ball if the length of the rope is 0.8m and its breaking strength is 0.9N
*June 14, 2014*

**Physics**

A wheel with radius of 25cm turning at 120 rpm uniformly increases its frequency to 660 rpm in 9s. Determine: i) the centripetal acceleration ii)the total acceleration of the system
*June 14, 2014*

**science**

calculate the mass of Cuso4.5H2O required to prepare 500 cm3 of a 0.400 m/dm-3 solution
*June 8, 2014*

**chemistry**

46,318.97
*June 8, 2014*

**chemistry**

calculate the mass of Cuso4.5H2O required to prepare 500 cm3 of a 0.400 m/dm-3 solution
*June 8, 2014*

**Product MGT**

At the grocery store, you buy a pack of 18 eggs and decide that when you get down to only 6 eggs you will buy another 18. In this scenario, what is your re order point? In this situation, what is your order quantity ?
*April 29, 2014*

**math**

Solve the equation z^2 + 2j = 0 Then convert solutions to Cartesian form.
*April 12, 2014*

**Science**

Which element would be most reactive? a. Al b. Cl c. P d. Na I initially thought that the answer was B, but I'm not sure about it. My second question is... Which non-metal is most reactive? a. Cl b. F c. I d. S I'm not sure about the answer for this one since all of ...
*March 24, 2014*

**math**

if f(x)=1-3x and g(x)=x^2-1, find : f(g(x))
*March 22, 2014*

**math**

if f(x)=1-3x and g(x)=x^2-1, find : g(g(x)), and g(f(x))
*March 22, 2014*

**math**

solve the equation 5coshx + 3sinhx = 4
*March 22, 2014*

**science**

Describe an experiment you might perform to determine which leg muscles of a frog are important for jumping long distances.
*March 18, 2014*

**Math**

Solve the inequality 4 ≤ 2c +7 ≤ 21
*March 9, 2014*

**Math**

Solve the inequality 4 ≤ 2c +7 ≤ 21
*March 9, 2014*

**math**

alice builds a model house she uses a scale of 1:20 the height of the real house is 10 meters. (i) what is the height of the model. the width of the model is 80cm (ii) what is the height of the real house
*March 5, 2014*

**Math**

Leah is buying curtains for her bedroom window. She wants the curtains to hang from the top of the window to the floor. The window is 4 feet high. The bottom of the window is 2 1/2 feet above the floor. What curtain length should Leah buy? a) 72 inches b) 78 inches c) 84 ...
*February 27, 2014*

**science**

liquid alcohol will change to vapor when its temperature reaches the A. boiling point B. fusing point C. freezing point D. melting point
*January 30, 2014*

**science**

a silver bar 0.125 meter long is subjected to a temperature change from 2oo degrees celsius to 100 degrees Celsius what will the length of the bar be after the temperature change
*January 30, 2014*

**science**

If the absolute temperature of gas is 600K, the temperature in degrees celsius is A.273 b.705c
*January 30, 2014*

**literature**

The story of The Wolf use.by Chief Pontiac is an example of A. a simile B. a myth c. personification
*January 30, 2014*

**literature**

When does the narrative of sojourner truth take place
*January 30, 2014*

**English**

If you consider The Call of the Wild to be an allegory, which one of the following statements would be true: Judge Miller represents the primordial condition.B Buck represents some characteristic of humanity
*January 29, 2014*

**literature**

In "A Pair of Silk Stockings," The silk stockings are a symbol of what
*January 24, 2014*

**Math**

4 in/sec = ? ft/h
*January 22, 2014*

**physics**

A 15.0 kg dart is thrown horizontally into a dartboard. The thrower applies a 80.0 N force over a distance of 88.2 cm in order to propel the dart. a) Calculate the work done by the dart thrower. b) Determine the velocity of the dart. c) If the dart went 4.50 cm into the ...
*January 9, 2014*

**physics**

We hang a mass of 500kg on a cylindrical steel rod of radius 0.5 cm and length 1 m. How much will the rod stretch? Young's modulus: steel 12*10^10 N/m^2. Now change steel to nylon. How much will it stretch? Nylon: 0.36*10^10 N/m^2. Thanks.
*January 7, 2014*

**physics**

What is the ratio of the spin angular momentum of the earth and its orbital angular momentum about the sun. The mean radius of the earth is R=6400km. The radius of the earth's orbit is r=1.5*10^8km. You may assume the mass of the earth is uniformly distributed throughout ...
*January 6, 2014*

**math**

The equation: T= 2* pi* sqrt(2/3L/9.8) Solve for L. Please show the solution step by step. The square root is giving me trouble in my solution. Thanks for your help.
*January 1, 2014*

**physics**

The largest ballon ever flown had a volume of 53 million cubic feet. The thickness of the fabric is only 0.013mm. The balloon would reach an altitude of 150,000 ft. ( 46 km). The atmospheric pressure at that altitude is about 2*10^-3kg/m^3. The pressure of the helium was the ...
*January 1, 2014*

**physics**

I want to lift a 3000kg car with a hydraulic jack. With a lever, I can easily build up by hand a force = 300 N on a piston of 10cm^2 surface area. What area should the piston have that pushes the car? a. 1 cm^2; b. 10 cm^2; c. 100 cm^2; d. 1000cm^2 I answered with c. 100 cm^2 ...
*January 1, 2014*

**physics**

What is the radius of the event horizon (or Schwartzchild radius) of approximately 4 million solar masses at the center of our galaxy? A. 1200 m; B. 12*10^6 km; C. 12*10^9 km; D. 12*10^12 km.
*December 30, 2013*

**physics**

In an elastic 1 -dimensional collision, a mass m1=3 kg with velocity v1 = -4 m/s collides with a mass m2 = 5kg at rest. What are the velocities v1' and v2' after the collision? I would like to your method of solving this problem. Thanks.
*December 28, 2013*

**physics**

Thanks Elena for your help. I have been having trouble with some of these equations.
*December 27, 2013*

**physics**

We release an object of mass M at zero speed at a distance of 2*10^6 Km from the center of the earth. What is the speed at which the object hits the earth? G=6.67*10^-11; g= 9.8 m/s; M=5.97*10^24; r=6.3781*10^6 Suppose the mass of the object is M= 500 kg. What is the kinetic ...
*December 27, 2013*

**physics**

The density of liquid carbon dioxide is about 0.8 g/cm^3. What volume fraction inside the fire extinguisher (when it is full) is occupied by liquid CO2? The density of CO2 gas is negligible compared to the density of liquid CO2. Volume of fire extinguisher is 7.1*10^-3m^3; ...
*December 24, 2013*

**physics**

V (fire extinguisher) = 7.1*10^-3 m^3 Mass CO2 = 4.5 kg T =293 K Pressure = 60*10^5 Pa
*December 23, 2013*

**physics**

The density of liquid carbon dioxide is about 0.8 g/cm^3. What volume fraction inside the fire extinguisher (when full) is occupied by CO2? The density of CO2 gas is negligible compared to the density of liquid CO2. My answer was 75%. Please verify. Thanks.
*December 23, 2013*

**Math**

Evaluate the expression.Express the result in scientific notacion: (7.1x10^5)-(4.3x10^2)
*December 16, 2013*

**Math URGENT**

3.8y+4/7x+2=0 Please help me. Thanks
*December 10, 2013*

**math**

Last week, Jake spent 6 1/4 hours reading, and Julia spent 3/5 as many hours as Jake did. How many hours did Julia spent reading?
*December 3, 2013*

**math**

Last week, Charles spent 2 hours watching television. Madoline watched television for 2/5 as many hours as Charles did. How many hours did Madoline spend watching television?
*December 3, 2013*

**chemistry**

2.5g of magnesium is how many moles? How do i set it up? Help would be awesome thanks.
*December 2, 2013*

**math**

a man can row a bangka at a rate of 5 km/h in still water. It takes 10 minutes longer to row upstream a distance of 2km than he takes to row downstream. What is the rate of the current?
*November 25, 2013*

**Find the value of K (Polynomial)**

Dtermine the value of K such that -2 is cone root of the equation 2x^3+(K+1)x^2=4-x^2 I tried it a couple of times and I keep getting the wrong answer. The answer is K=3.
*October 6, 2013*

**Math Factoring with 3 VARIABLES?!?!**

a^2-b^2+8bc-16c^2 25-m^2-12mn-36n^2 x^2-a^2-y^2-2ay I know that you have to group them 3 and 1 and then you have to do difference of squares but I am utterly lost how to go about it. Please help!
*October 5, 2013*

**Math**

What is the perimeter of a regular hexagon with an area of 294ã3 ?
*September 16, 2013*

**Integers**

If x and y are positive integers and x/5 + y/8 = 17/20, what is the value of x + y?
*September 16, 2013*

**Polynomial Functions**

I don't have problems with the transformations. Just graphing the base function is my problem because I don't know the image points.
*September 11, 2013*

**Polynomial Functions**

I have to graph some graphs but I don't the main image points for the base function to make transformations. Specfically, f(x)=x^3 f(x)=x^4 f(x)=x^5 and it goes on. How do I find them to make my transformations?
*September 11, 2013*

**English**

Who is the Antagonist in Amy Tan's "A Pair of Tickets"? I know the Protagonist is June May but I couldn't figure out who the antagonist was. Yes, I have read the short story
*September 11, 2013*

**math**

a drapery panel measures 6 feet by 10 feet. Find how many square feet of material are needed for eight panels?
*September 1, 2013*

**physics**

A 1200W engine supplies a force of 90N to move an object at a constant velocity. With what velocity will it move?
*August 15, 2013*

**Physics**

A radioactive substance decays from 2.0kg to 1.6kg in 156 days. How long would it take to decay to 1.1kg?
*August 7, 2013*

**Physics**

A radioactive substance decays from 2.0kg to 1.6kg in 156 days. How much will be left after 201 days?
*August 7, 2013*

**Physics**

A radioactive substance decays from 2.0kg to 1.6kg in 156 days. What is the decay constant and the half life of the substance?
*August 6, 2013*

**physics**

A granite column in a building is 8.50 m high and has a mass of 2.16 multiplied by 104 kg. (a) How much heat (J) is needed to increase its temperature by 10.5°C, given its specific heat is 0.200 kcal/kg·°C? (b) What is its change in length (m) if its coefficient...
*July 24, 2013*

**physics**

A certain heat engine does 8.0 kJ of work and dissipates 8.00 kJ of waste heat in a cyclical process. (a) What was the heat input to this engine? (b) What was its efficiency?
*July 24, 2013*

**physics**

I don't know which are the "area" and "V". Can you show me the steps. Thanks.
*July 24, 2013*

**physics**

A hand-driven tire pump has a 2.50 cm diameter piston and a maximum stroke of 31.0 cm. (a) How much work do you do in one stroke if the average gauge pressure is 2.40 multiplied by 105 N/m2 (about 35 psi)? (You may consider this an isothermal process.) (b) What average force ...
*July 24, 2013*

**Physics**

A particular brake design can apply a force of 2000 N. If you wish to have a deceleration of 5m s1, what is the largest car weight you can use with this design?
*July 22, 2013*

**physics**

A 3.00 g lead bullet traveling at 640 m/s strikes a target, converting its kinetic energy into thermal energy. It's initial temperature is 40.0°C. Find the available kinetic energy of the bullet. Find the heat required to melt the bullet.
*July 21, 2013*

**physics**

The formation of condensation on a glass of ice water causes the ice to melt faster than it would otherwise. If 7.40 g of condensation forms on a glass containing water and 210 g of ice, how many grams will melt as a result? Assume no other heat transfer occurs. Use the heat ...
*July 21, 2013*

**physics**

(a) How many kilograms of water must evaporate from a 60.0 kg woman to lower her body temperature by 0.750°C?
*July 21, 2013*

**physics**

The sun radiates like a perfect blackbody with an emissivity of exactly 1. (a) Calculate the surface temperature(K) of the sun, given it is a sphere with a 7.00 multiplied by 108 m radius that radiates 3.80 multiplied by 1026 W into 3 K space. (b) How much power(W/m^2)does the...
*July 21, 2013*

**Physics**

The sun radiates like a perfect blackbody with an emissivity of exactly 1. (a) Calculate the surface temperature(K) of the sun, given it is a sphere with a 7.00 multiplied by 108 m radius that radiates 3.80 multiplied by 1026 W into 3 K space. (b) How much power(W/m^2)does the...
*July 20, 2013*

**physics**

The "steam" above a freshly made cup of instant coffee is really water vapor droplets condensing after evaporating from the hot coffee. What is the final temperature of 200 g of hot coffee initially at 90.0°C if 2.00 g evaporates from it? The coffee is in a ...
*July 20, 2013*

**Physics**

On a certain dry sunny day, a swimming pool's temperature would rise by 1.60°C if not for evaporation. What fraction of the water must evaporate to carry away precisely enough heat to keep the temperature constant? (Lv =2430kJ/kg or 580kcal/kg)
*July 20, 2013*

**physics**

The formation of condensation on a glass of ice water causes the ice to melt faster than it would otherwise. If 8.80 g of condensation forms on a glass containing water and 170 g of ice, how many grams will melt as a result? Assume no other heat transfer occurs. Use the heat ...
*July 20, 2013*

**physics**

A slab of a thermal insulator with a cross-sectional area of 115 cm2 is 4.00 cm thick. It is made out of red brick with thermal conductivity 0.600 J/s∙m•C°. The temperature difference between opposite faces is 95.0 C°. Calculate the following: (a) The heat ...
*July 20, 2013*

**physics**

A 2.60 kg steel gas can holds 15.0 L of gasoline when full. What is the average density of the full gas can, taking into account the volume occupied by steel as well as by gasoline?
*July 18, 2013*

**physics**

A 2.60 kg steel gas can holds 15.0 L of gasoline when full. What is the average density(kg/m^3)of the full gas can, taking into account the volume occupied by steel as well as by gasoline?
*July 18, 2013*

**physics**

The greatest ocean depths on earth are found in the Marianas Trench near the Philippines, where the depth of the bottom of the trench is about 11.0 km. Calculate the pressure(atm)due to the ocean at a depth of 10.1 km, assuming sea water density is constant all the way down...
*July 18, 2013*

**physics**

A 2.60 kg steel gas can holds 15.0 L of gasoline when full. What is the average density of the full gas can, taking into account the volume occupied by steel as well as by gasoline?
*July 18, 2013*

**physics**

A 2.60 kg steel gas can holds 15.0 L of gasoline when full. What is the average density of the full gas can, taking into account the volume occupied by steel as well as by gasoline?
*July 18, 2013*

**Physics**

A train initially travelling at 30ms^1 decelerates at 4ms^2. (a) What time will it take to slow to 5m s^1? (b) What distance will it have travelled when it has slowed to 5ms^1?
*July 16, 2013*

**Physics**

An object accelerates from 10m/s to 16m/s in 10 secs. What will be the object’s velocity after 1 minute?
*July 16, 2013*

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