Friday

May 27, 2016
Total # Posts: 1,173

**mechanics**

what is the kinetic energy of an object that has a mass of 20nkilograms and a speed of 2.8 m/s
*July 18, 2011*

**Physics**

Question: When a balloon is rubbed with fur, it becomes negatively charged. Explain why?
*July 17, 2011*

**Math**

A person standing near the edge of a cliff 120 feet above a lake throws a rock upward with an initial speed of 40 feet per second. The height of the rock above the lake at the bottom of the cliff is a function of time and is described by the function H(t) = –16t2 + 40t + ...
*July 16, 2011*

**chemistry**

How could I determine if one rock is denser than another rock?
*July 14, 2011*

**physics**

A ray of light enters the top of a glass of water at an angle of 36 degrees with the vertical. What is the angle between the refracted ray and vertical? The answer is 26 degrees but I keep getting 22 degrees. I used snell's law: n1sinθ1=n2sinθ2 for n1 I thought ...
*July 13, 2011*

**Physics**

A string with a linear density of 0.035 kg/m and a mass of 0.014 kg is clamped at both ends. Under what tension in the string will it have a fundamental frequency of 100 Hz? The correct answer is 270N but I don't know how to get there. Here are some of the equations we can...
*July 13, 2011*

**CHEMISTRY**

Analyze the properties of a sodium atom and a sodium ion. What are the differences in mass, stability, and reactivity that are caused due to the differences between the sodium atom and sodium ion?
*July 13, 2011*

**Med terms**

Andrea is not 100% right. left lower lobe = lower left lobe (LLL)
*July 12, 2011*

**Physics**

Question: Two strings at different lengths and linear densities are joined together. They are stretched so that the tension in each string is 190.0 N. The free ends are fixed in place. Find the lowest frequency that permits standing waves in both strings with a node at the ...
*July 11, 2011*

**Physics**

1. A person driving to the right and honks their horn. An observer standing behind the car, opposite its direction of motion would hear...(choose one) a. Higher Pitch b. Lower Pitch c. Same pitch as the driver please explain how you got to the answer
*July 10, 2011*

**economics**

At an initial point on the aggregate demand curve, the price level is 100, and real to GDP is $15trillion. After the price level rises to 110, however, there is an upward movement along the aggregate demand curve, and real GDP declines to $14 trillion. If total autonomous ...
*July 9, 2011*

**economics**

Suppose that Congress enacts a lump-sum tax cut of $750 billion. The marginal propensity to consume is equal to .075. Assuming that Ricardian equivalence holds true, what is the effect on equilibrium real GDP? On saving?
*July 9, 2011*

**math**

How did you get that answer? I can't come up with the equations, I got them but I didn't get that answer
*July 8, 2011*

**math**

A manufacturer makes two products A and B, each of which is processed in two departments, production and finishing. Each A takes 3 hours to produce and six hours to finish, whereas each B takes 5 hours to produce and 2 hours to finish. How many units of A and B can be produced...
*July 8, 2011*

**Micoreconomics**

In recent years, the Internet auction firm eBay has sougth to make its auction technology the favorite of software programmers, and it has begun licensing its technology to other Web sites. The company's managers have pulicly stated that their goal is for eBay's ...
*July 8, 2011*

**Physics**

I need a complete list all the doppler effect equations for a beginner physics class. Here is a sample questions so you know the level Question: Two trains on separate tracks move toward one another. Train #1 has a speed of 130 km/hr and train #2 a speed of 90km/hr. Train 2 ...
*July 7, 2011*

**MATH**

10(10)+ 5(10)
*July 7, 2011*

**Algebra**

Can you help me solve this please? 31%=1-600/Q Answer: 869.6 But in don't know how to get to the answer
*July 7, 2011*

**Physics**

1. Water with a mass of 2kg is held at constant volume in a pressure cooker. 10,000 J of energy is added from the heater inside the pressure cooker. The container is not terribly well insulated, so the container leaks 2000 J of energy to the surrounding air. What is the total ...
*July 6, 2011*

**algebra**

Determine whether 14 is a solution of the equation 6(x - 2)= 70
*July 6, 2011*

**Physics**

1. How much energy is required to be removed to lower the temperature of a bottle of drinking water (280mL) from 22°C to 4°C? The density of water is 1.0g/mL here are the equations we can use: (-m1)(C1)(ΔT1)=(m2)(C2)(ΔT2) Q=mcΔT Q=mL There might be ...
*July 5, 2011*

**chemistry**

A traveling wave is produced on a rope. The wave travels until it hits a wall and it is reflected. If the speed of the wave is 1.8 m/s and it takes 3.3 s to get back to the starting point, how long (m) is the rope.
*July 5, 2011*

**Education**

Can you explain why teachers who wish to promote a developmentally appropriate science education program must be knowledgeable about children's level of development.
*July 2, 2011*

**Education**

Why is science an integral part of the play-centered curriculum?
*July 2, 2011*

**Education**

What is the goal of early childhood science education?
*July 2, 2011*

**Education**

What is an example of play that relates to a curriculum standard in mathematics?
*July 2, 2011*

**physics**

The momentum before and after the explosion is the same. Since there are no external forces acting on the satellite, the law of conservation of momentum states that momentum will not change. Basically the total momentum of the satellite before the explosion is equal to the ...
*June 28, 2011*

**physics**

The momentum of a car traveling east is different from the momentum of an identical car traveling west at the same speed. Momentum is a measure that includes both the mass and the velocity of an object. The two cars have identical mass (I am assuming they have identical mass ...
*June 28, 2011*

**Physics Equation **

What is the equation for total energy (TE)?
*June 28, 2011*

**Physics**

Did you get 22/2 because it said halfway?
*June 28, 2011*

**Physics**

1. if a 0.05kg coin is hanging from 22m above the ground: a. If you drop it, how fast will the coin be moving halfway to the ground? b. How fast will it be moving just before it hits the ground? If you could point me the right direction with equations that would be great. I ...
*June 28, 2011*

**Physics **

What makes you think I just want answers. I am here to learn and simply showing me how to set up the problem is enough. Your answer was helpful but you don't have to be mean.
*June 28, 2011*

**Physics **

A 30kg block sits on a ramp, with Θ=47. The ramp is 13m off the ground at the tallest point. If the block slides in the presence of friction, with μ=0.1, how fast is the block moving when it hits the bottom of the ramp? Please indicate which equation you use, what ...
*June 28, 2011*

**Physics**

If you could just post the equations that would be helpful in this problem that would be great. I am sure I can figure it out form there. Also does TE stand for total energy?
*June 28, 2011*

**Physics**

A winch with a power rating of 400 W lifts a 200kg object off the ground at a constant velocity for 17 seconds. How high was the object lifted? What is the object total energy? Please indicate which equation you use, what variable corresponds to each number, and how you got ...
*June 28, 2011*

**Physics **

Question: A car is on a ramp 100m from the bottom of the ramp (angle of incline=30 degrees): a. If the potential energy of the car is 80902 J, how much does the car weigh? b. What is the KE half way down the ramp? c. What speed is the car moving at the bottom of the ramp? ...
*June 27, 2011*

**Physics**

Question: A 0.200kg ball moves with a velocity of 0.3m/s. It collides with a second ball that is at rest and has a mass of 0.1kg. After the collision, the velocity of 0.1kg ball is 0.26m/s. What is the new velocity of the first ball. Please indicate which equation you use, ...
*June 26, 2011*

**Physics **

1. A 0.75kg ball traveling horizontally to the right at 20m/s. A player strikes the ball and causes it to move in the opposite direction with a velocity of 24m/s. a. What impulse was delivered by the player to the ball? b. If this took 0.3 seconds to occur, What force must be ...
*June 26, 2011*

**Physics **

A cart of apples is rolling toward you in the street. It’s velocity is 2m/s. Its total mass is 50kg. You are running toward the cart of apples (hint your velocity is opposite direction of the carts velocity). You have a mass of 45kg. What velocity must you be running at ...
*June 26, 2011*

**Physics**

1. A 38kg object is traveling down the ramp and experiences a frictional force of 180N. Calculate the angle of incline and the friction coefficient between the two surfaces. Answers: μ(mu)=0.55 Θ=28.9 degrees But please show work and all equations/variables used.
*June 23, 2011*

**physics**

How can I find kinetic friction (Fk) without mu? I know the normal force which is 201N. The mass of the object is 30kg. This is the full questions of it helps. I just don't understand how to find kinetic friction 1. If a 30kg object experiences a normal force of 210N when ...
*June 22, 2011*

**Physics **

1. If a 30kg object experiences a normal force of 210N when traveling down a ramp, what is the angle of incline? Also, calculate the force of friction and the coefficient of friction. Answers: μ(mu)=0.98 Θ=44.5 degrees But please show work and all equations/variables...
*June 22, 2011*

**Physics**

1. If a 500N person is skiing on a slope with an angle of incline of 67 degrees and there was a friction coefficient of 0.19, determine the person’s acceleration rate. If starting from rest, what is the overall displacement after 30 seconds?
*June 22, 2011*

**chemistry**

Take a ruler and measure the height of the textbook three times. Record the three measurements, and discuss the uncertainty in your measurements. Remember to report the smallest markings on your ruler.
*June 20, 2011*

**Chemistry**

Part A Calculate the standard enthalpy change for the reaction 2A+B --->2C +2D Use the following data: Substance Delta H(kJ/mol) A -263 B -391 C +203 D -523 Express your answer in kilojoules. MY ANSWER FOR PART A: Delta H =277 kJ PART B----THIS ONE I NEED HELP ON Express ...
*June 16, 2011*

**Chemistry**

Part A Calculate the standard enthalpy change for the reaction 2A+B --->2C +2D Use the following data: Substance Delta H(kJ/mol) A -263 B -391 C +203 D -523 Express your answer in kilojoules. MY ANSWER FOR PART A: Delta H =277 kJ PART B----THIS ONE I NEED HELP ON Express ...
*June 16, 2011*

**health**

How might the increase in medical technology have a negative effect on communication among providers? Provide at least two examples. Are there any positive effects of increased technology on communication among providers? Why or why not? How does the increase in medical ...
*June 9, 2011*

**health**

How might the increase in medical technology have a negative effect on communication among providers? Provide at least two examples. Are there any positive effects of increased technology on communication among providers? Why or why not? How does the increase in medical ...
*June 9, 2011*

**com**

Can you please identify the adverbs and adjectives in the following paragraph. Having credit cards could get some people into serious debt. I had a credit card at one time. I learned the hard way about using credit cards. I was using it for anything and everything that I ...
*May 30, 2011*

**art**

Sato
*May 29, 2011*

**Calculus**

Differentiate the following function? g(x)=x^2=1/x^2-1
*May 29, 2011*

**Algebra II**

Translate this equasion 2 units left and 4 units up: 9x^2+ 3x+ 10= 16y^2+ 154+ 3x please show me all of the steps. thank you
*May 23, 2011*

**Chemistry**

A 15.5 mL sample of 0.215 M KOH solution requires 21.2 mL of acetic acid in a titration experiment. Calculate the molarity of the acetic acid solution. Please show all steps, I don't understand this.
*May 23, 2011*

**Chemistry**

If 15.omL of 0.0250 M aqueous H2SO4 is required to neutralize 10.0 mL of aqueous solution of KOH, what is the molarity of the KOH solution?
*May 23, 2011*

**Human Relations Part 1**

Strong feelings
*May 21, 2011*

**algebra**

Determine whether -4 is a solution of the inequality x>-4 Is -4 a solution?
*May 20, 2011*

**Management**

The business I choose to do my SWOT Analysis on is Infinite learning Childcare Center. The five resources I used to obtain my information on the business strength, weakness, opportunities, and threats, are parent surveys, the company’s handbook, employee’s, ODJFS web...
*May 17, 2011*

**chemistry**

12.1
*May 15, 2011*

**General - URGENT**

I have found the cartoon on a website, but not the original details. It says LEV HAUS, do not trust the Kulak he is the enemy of socialism in the caption.
*May 14, 2011*

**General - URGENT**

Hi Theres this cartoon, it says: Kulak je nejzavilejsi nepritel socialismu. It shows a small fat man lifting up the cheek of a taller man as if he likes him. The shadow shows the fat man chocking the thin man and instead of a torch/candle behind him he is carrying a knife ...
*May 14, 2011*

**Reseach - source evaluation HELP**

Okay, I'll try contacting them. When I research George Beers I keep getting a hockey player or a dude who was dead before Stalin was alive!
*May 14, 2011*

**english**

huh? By the South African revolution do you mean the overthrow of the aprtheid regime? Explain 'customs'. Is it border control or cultural activities?
*May 8, 2011*

**Easy maths question**

Thanks!
*May 8, 2011*

**Easy maths question**

Hey How do I convert 1224.78m squared into mm squared?
*May 8, 2011*

**Current Events**

Hey! Kayz, so regarding the stance 'that the US should remove political, social and economic support from dictatorships'. So far I'm thinking of adapting the sanctions on South Africa during apartheid for this. I'm also thinking of looking at current ...
*May 8, 2011*

**grammar**

What is the question?
*May 8, 2011*

**English**

No. See you're describing something right? In each of those sentances. If someone was listening to you, would you rattle off a list of things that could happen? NO! You would draw ther attention to one thing that occurs ie superman can run faster than a speeding bullet ...
*May 7, 2011*

**English**

I'll give some examples.. 8- Smart people learn from their own mistakse but the smartest people learn from the mistakes of others. 7- When driving, drivers should not only refrain from using mobile phones but also refrain from eating and drinking or fiddling with radio ...
*May 7, 2011*

**Math - doing something wrong somewhere**

Okay, am I doing my conversions wrong?
*May 7, 2011*

**Chemistry**

You have 3.00 L of a 2.37 M solution of NaCl(aq) called solution A. You also have 2.00 L of a 2.00 M solution of AgNO3(aq) called solution B. You mix these solutions together, making solution C. Calculate the concentration (in M) of Na+ ions in solution C.
*May 6, 2011*

**chemistry**

Data: freezing point of pure cyclohexane: 6.0 degrees celcius Freezing point of unknown soluton: 1.6 degrees celcius weight of cyclohexane: 40.0231g=0.0400231 kg weight of unknown solute: 0.4872 g K_f_ of cyclohexane: -20.00 degrees Celciusx kg/mole questions: 1. what is the ...
*May 2, 2011*

**chemistry, please help!**

Given: 1. Mass of oxalic acid + weighing paper 2.0355g 2. Mass of weighing paper 0.5219 g 3.volume of oxalic acid solution 250 mL 5. Volume of oxalic acid used in titration trial 1: 15.o mL Trial 2: 15.0 mL 6. Volume of NaOH solution used in titration: Trial 1: 12.1 mL trial 2...
*May 2, 2011*

**chemistry**

To what volume must a solution of 83.1 g H2SO4 in 505.3 mL of solution be diluted to give a 0.28 M solution? I do not understand this problem. Also as a hint the professor said to use M1V1= M2V2.
*April 28, 2011*

**chemistry**

molarity = moles solute / L solution Convert g to moles: 23g NaCL x 1 mol/58.44 g NacL = 0.394 mol Convert ML to Liter: 500 mL x 1 L /1000 mL = 0.5 L Therefore... M= 0.394 mol/0.5L = 0.788 Molarity.. should be the right answer
*April 28, 2011*

**Please HELP CHEM**

How many grams of CaCl2 would be required to be added to water to prepare 1liter (1000ml) of a 1.72% (w/v) aqueous solution of CaCl2?
*April 28, 2011*

**Math**

Alright let friend one be represented by x, freind two by y and friend three by z. So 17feet 8 inches needs to be converted. Write out all that you know in algebra formulas. x+y+z= x= y= z= and solve. Or just use the first formula and solve for each value by inserting the ...
*April 24, 2011*

**Math calculus-Trig**

Find the area bounded by the curve and the lines y = -x^2 - 4x; y = 1; x = -3; x = 1
*April 21, 2011*

**Math**

Explain why the vertices of a solution region are important when using linear systems of inequalities for optimization problems ?
*April 20, 2011*

**Math**

A round 12-inch woofer is mounted to the bottom of a rectangular speaker enclosure with an inner width measurement of 12 inches. How far from corner A is the center, O, of the woofer?
*April 20, 2011*

**algebra**

Simplify this expression. If the answer contains exponents, all exponents should be positive. t 9 (t 6 ) 4
*April 20, 2011*

**world history**

neanderthals lived near homo sapians for thousands of years
*April 14, 2011*

**algebra**

What is the distibutive property to multiply using this equation? 12(u+v)
*April 8, 2011*

**algebra**

5/16 + 3/24
*April 7, 2011*

**chemistry**

In calibrating a thermometer by setting only the freezing and boiling points, what assumptions are you making regarding the internal diameter of the thermometer and the expansion of alcohol?
*April 6, 2011*

**chemistry**

In calibrating a thermometer by setting only the freezing and boiling points, what assumptions are you making regarding the internal diameter of the thermometer and the expansion of alcohol?
*April 6, 2011*

**statistics**

Is it ever inappropriate to report the mean? If so, when?
*April 4, 2011*

**math**

find mass of 2.7 grams of aluminum if volume is 1 cubic meters
*April 1, 2011*

**math**

find mass of 2.7 grams of aluminum if mass is 1 cubic meters
*April 1, 2011*

**ENG 121**

what are some examples of similarities and differeces in working mothers vs stay at home mothers?
*March 31, 2011*

**marketing**

discuss the legal and ethical implications that could affect the marketing process with nutrition life cycle of school age children
*March 29, 2011*

**Math**

Sketch the graph of a function f that satisfies all the following conditions. (a) f(0)=0,f'=1 (b) f''(x)>0 for x<0, f''<0 for x>0
*March 28, 2011*

**Math**

Find the vertical and horizontal asymtotes of y=1/x^2+6x+9
*March 28, 2011*

**Math ( calculas)**

find the intervals on which the curve y=x/(x+1)^2 is concave upward or concave downward.
*March 27, 2011*

**Math**

Rchel has 14 red, 9 blue, and one yellow towel. In haw many ways can the towels be arranged if the towels of the same colour must be side by side?
*March 23, 2011*

**chemistry**

The electron in a hydrogen atom is excited and makes a transition from n=2 to n=7 a. calculate the energy of the photon absorbed in joules. b. calculate the wavelength of the photon in meters HOW DO I DO THIS?
*March 21, 2011*

**Chem**

what occurs during the reaction below 4Hcl+MnO2-->MnCl2+2H2O+Cl2 1.the manganese is reduced and its oxidation number changes from +4 to +2. 2.the manganese is oxidized and its oxidation number changes from +4 to +2. 3.the manganese is reduced and its oxidation number ...
*March 20, 2011*

**Elements of Statistics**

the world health organization's center of aids research is planning to write a report on aids infection among drug users all of the world. in a recent study conducted on 1,000,000 drug users, 52% indicated that they are using heroin on regular basis, 37% indicated that ...
*March 19, 2011*

**Chemistry (organic)**

compound x C29H48BrCl reacts with excess H2/pd to give C29H56BrCl. How many double bonds and how many rings are in X?
*March 18, 2011*

**math**

How do the 2000 and 20pyg cancel out...the first pyg is still there?
*March 14, 2011*

**math**

(Px – 20) (100 – 2 Px + Pyg) Differentiating with respect to P we get 100 – 4Px + Pyg + 40 = 0 I dont understand how this is calc... whenever I multiply through and take the deriv I get another answer. Do you first multiply Px through then 20??
*March 14, 2011*