Sunday

February 7, 2016
Total # Posts: 633

**chemistry**

He has narrowed the identity of his unknown to either molecule X, molecule Y, or molecule Z. The Merck Index tells him that all three molecules produce white, needle-like crystals from ethanol. How might he definitively identify his unknown molecule?
*February 2, 2016*

**physics**

an operating 100-watt lamp is connected to a 120-volt outlet. what is the total energy used by the lamp in 60. seconds
*January 27, 2016*

**Math**

Upon retirement (in 40 years) you want to receive $10,000 each month for a period of 28 years. This money resides in an account that pays 5.9% interest. How much money must be in the account to fulfill your goal?
*December 2, 2015*

**Mathematics**

Show that the equation tanθ = sinθ can be written in the form sinθ(1 - 5cosθ) = 0?
*November 18, 2015*

**Mathematics**

Solve 2cos^2(x) + 4sin(x)-3 = 0, giving all solutions in the interval 0 ≤ x ≤ 2π
*November 18, 2015*

**Mathematics**

Given that 2cos^2 x - 3sin x -3 = 0, show that 2sin^2 x + 3sin x +1 = 0? Hence solve 2cos^2 x + 4sin x - 3 = 0, giving all solutions in the interval 0 ≤ x ≤ 2π
*November 18, 2015*

**Calculus**

A tennis ball is dropped from a height of 32 feet, rebounding to 1/2 its former height with each bounce. How far will the ball have traveled VERTICALLY when it comes to a rest?
*November 16, 2015*

**Algebra **

If a certain number is added to the numerator and denominator of 11/13, the result is 11/12. Find the number.
*November 4, 2015*

**Physics**

A block of 3kg is pulled up a smooth slope with a force of 24N and the slope is of an angle 25 degrees. Calculate the acceleration of the block up the slope.
*November 2, 2015*

**Physics**

A car traveling at a velocity of 2m/s undergoes an acceleration of 4.5m/s2 over a distance of 340m.How fast will it be going after the acceleration?
*October 29, 2015*

**Physics**

A car of mass 1300 kg is driving along a road at speed of 28m/s. As it approaches some traffic lights, the lights change to red and the driver applies his brakes causing the car to skid. The frictional force between the skidding tyres and the road is 0.8 of the weight of the ...
*October 25, 2015*

**Physics**

A car of mass 1300 kg is driving along a road at speed of 28m/s. As it approaches some traffic lights, the lights change to red and the driver applies his brakes causing the car to skid. The frictional force between the skidding tyres and the road is 0.8 of the weight of the ...
*October 25, 2015*

**Physics**

A man runs east 9.8 m/s for 11 s, stops for 6.9 s, then runs back (west) at 1.5 m/s for 1.2 s. What is the man's average velocity?
*October 8, 2015*

**Physics**

A soccer ball is kicked with resultant velocity of 22.6 m/s at an angle of 60 degrees. What is the time to Apex, what is the range of the kick? r = 22.6 angle = 60 degrees 1)Vxi=sin(60)(22.6) = 19.57 Vyi=cos(60)(22.6) = 11.3 2)T= Vyf-Vyi/A 0-11.3/-9.81 = 1.1 sec time to apex ...
*October 7, 2015*

**Math**

The circumference of a rear wheel of a carriage is 50 inches more than a front wheel. If the rear wheel makes as many revolutions in going 200 feet as the front wheel in going 120 feet, find the length of the circumference of each wheel.
*September 27, 2015*

**Math**

In a third game. Javier first two darts land in R what is the maximum possible score in this game
*September 23, 2015*

**geometry**

yes you're correct
*September 4, 2015*

**STATISTICS**

According to the DPT of Health Services , 12% of 30-39 have depression. Suppose 3 30-39 year olds are selected randomly what is the probability that all three will have depression.
*August 13, 2015*

**Math**

Find equations of the osculating circles of the ellipse 9x^2+4y^2=36 at the points (2,0)&(0,3).
*July 5, 2015*

**Math**

Find the curvature x=t^2, y=t^3 Using k=|xÿ-yx|/(x^2+y^2)^3/2
*July 5, 2015*

**Differential Equation**

Given A=2i+3j and B=4i-j Compute for the following a. |a|+|b| b. 5A-6B c. |5A-6B| d. |5A|-|6B|
*June 23, 2015*

**Math**

Alice takes 4 hours to paint a wall. With sam's help, they can paint the wall in 3 hours. Without help, how long would it take Sam to do the same thing?
*June 6, 2015*

**Trigonometry**

y = + or - 3 cos (2 theta + 3/2 pi) - 3 is my answer
*June 4, 2015*

**Trigonometry**

Write an equation of the cosine function with the given amplitude, period, phase shift, and vertical shift. amplitude = 3, period = pi, phase shift = -3/4 pi, vertical shift = -3
*June 4, 2015*

**Trigonometry**

Find tan theta if theta is an angle in standard position and the point with coordinates (â€“12, 5) lies on the terminal side of the angle.
*May 26, 2015*

**algebra**

g(x)=5, find g(-4) g(-4)=5 -4g=5 g=-1.25
*May 26, 2015*

**ALGEBRA**

Jan plans to invest $7500, part at 4% simple interest and the rest at 5% simple interest. What is the most that he can invest at 4% and still be guaranteed at least $325 per year?
*April 30, 2015*

**ALGEBRA**

Find the distance between the points (-2, 3) and (4, -5)
*April 29, 2015*

**Physics**

An equal amount of heat is transferred to two containers containing water at the same temperature. If the second container contains three times as many water molecules as the first, how do the final temperatures compare?
*April 26, 2015*

**Physics**

A liter of water is used to cool some electronics. If 1000 J of heat is given off by the electronics, by what temperature does the water increase? One liter of water has a mass of 1 kg and a specific heat of 4.184 J/(g °C). I can not get this..please help
*April 26, 2015*

**algebra**

If f(x) and g(x) are two functions defined by f(x) = ã(x + 1), g(x) = | x - 1 |, then what is the value of f(g(9))?
*April 23, 2015*

**College algebra**

. If i = ¡Ì-1, then (i + 1)(6i ¨C 10) is equivalent to?
*April 23, 2015*

**College Algebra**

The function w(x) = -0.01x² + 0.27x + 8.60 can be used to estimate the number of self-employed workers in America in millions, x years after 1980. For what years were there (or will be there) 9.7 million self-employed worker in America?
*April 23, 2015*

**math **

The area of a triangle is 600 square feet. Find the altitude, in feet, of the triangle if the length of the corresponding base is 30 feet.
*March 26, 2015*

**math(5th grade)**

1/2 x 1/4 = 1/8 are 5th grade boys
*February 26, 2015*

**Algebra 1**

Seiji and Gavin both worked hard over the summer. Together, they earned a total of $425. Gavin earned $25 more than Seiji. Hoe much did each of them earn? A. Write a system of two equations to model this program. I got 1 equation down, i just cant figure out the second
*January 23, 2015*

**Physics**

A cannon is fired at 30 degrees above the horizontal with a velocity of 200 m/s from the edge of a 125 m high cliff. Calculate where the cannonball lands on the level plain below.
*January 18, 2015*

**!@#$%^& her right in the !@#$%^&**

Lol lol lol
*January 15, 2015*

**Physics**

A 3kw engine operates for 3secs, 10kgf force is applied find the Displacement.
*January 14, 2015*

**Physics**

Converging lens has focal lenght 8 cm , at what distance you will have to place the object in the following devices; 1) Collimator of Spectrum 2) Terrestrial Telescope
*January 14, 2015*

**Physics**

A mass of 0.55 kg attached to a vertical spring stretches the spring 36 cm from its original equilibrium position. The acceleration of gravity is 9.81 m/s2 . What is the spring constant? Answer in units of N/m.
*January 12, 2015*

**Chemistry**

Is the boiling point of 0.01 m potassium fluoride solution higher or lower than that of 0.01 m glucose solution? Explain
*December 8, 2014*

**computer science**

The components of a traditional analysis model (data flow diagrams, process definitions, entity-relationship diagrams, and data definitions) were developed in the 1970s and 1980s as part of the traditional structured analysis methodology. How well do the components fit ...
*November 17, 2014*

**Systems Analysis**

This is the question that was asked: The components of a traditional analysis model (data flow diagrams, process definitions, entity-relationship diagrams, and data definitions) were developed in the 1970s and 1980s as part of the traditional structured analysis methodology. ...
*November 17, 2014*

**art history**

That's the answers I would agree with for your study guide. All the other answers for the choices on #7, I could disprove, but I could find nothing to prove this one correct.
*November 17, 2014*

**art history**

1. Yes, but could find no resources to confirm for you. 2. No, and there's a resource that helps describe it... 3. Yes, this was a no-brainer for me. However, I found no specific resource to back it up. I would go with this answer if it were me. 4. No, and there's a ...
*November 17, 2014*

**statistics**

Customers arrive at a movie theater at the advertised movie time only to find that they have to sit through several previews and prepreview ads before the movie starts. Many complain that the time devoted to previews is too long (The Wall Street Journal, October 12, 2012). A ...
*November 16, 2014*

**physics**

That didn't answer the question
*November 7, 2014*

**physics**

A cannon fires a 0.598 kg shell with initial velocity 10 m/s in the direction 46◦ above the horizontal. The shell’s trajectory curves downward be- cause of gravity, so at the time t = 0.53 s the shell is below the straight line by some verti- cal distance ∆h. ...
*November 7, 2014*

**Math: Statistics**

12
*October 28, 2014*

**physics**

A 1.0-kg cart and a 0.50-kg cart sit at different positions on a low-friction track. You push on the 1.0-kg cart with a constant 2.5-N force for 0.15m . You then remove your hand, and the cart slides 0.35 m and strikes the 0.50-kg cart. By what amount does your force change ...
*October 23, 2014*

**science-chemistry**

An aqueous solution of ammonium nitrite decomposes when heated to give off nitogen gas and water. This reaction can be used to prepare pure nitrogen gas. How many grams of ammonium nitrite must have reacted if 3.75 liters of nitrogen gas was colleced over water at 25˚C ...
*October 20, 2014*

**Chemistry**

An aqueous solution of ammonium nitrite decomposes when heated to give off nitrogen gas and water. This reaction can be used to prepare pure nitrogen gas. How many grams of ammonium nitrite must have reacted if 3.75 liters of nitrogen gas was collected over water at 25˚C ...
*October 20, 2014*

**chemistry**

Can someone help me with Chemistry Homework Due Tomorrow, Its about the Electrolysis of Hydrochloric Acid Practical we did and I Have to write a summary and I dont get what we did Y10 GCSE Higher Tier
*October 20, 2014*

**Chemistry**

The speed of light in a vacuum is 2.998 x 10^8 m/s. What is the speed of light in miles per hour? (1 km = 06214 miles)
*October 14, 2014*

**Physics**

The hare and the tortoise are at the starting line together. When the gun goes off, the hare moves off at a constant speed of 10 meters per second. (Ignore the acceleration required to get the animal to this speed.) The tortoise starts from a dead stop, but accelerates at a ...
*October 2, 2014*

**Physics**

A train is moving parallel and adjacent to a highway with a constant speed of 22 m/s. Ini- tially a car is 35 m behind the train, traveling in the same direction as the train at 36 m/s and accelerating at 4 m/s2. What is the speed of the car just as it passes the train? Answer...
*October 2, 2014*

**Physics**

v= 61.3m/s at max h straight line= 264.1m
*September 15, 2014*

**physics**

Due to continental drift, the North American and European continents are drifting apart at an average speed of about 3 cm per year. At this speed, how long (in years) will it take for them to drift apart by another 658.1 m?
*September 7, 2014*

**science**

from its name macro- means a large amount of substances or nutrients required for living organisms. Let me know if my answer helped you.
*September 6, 2014*

**P.E**

The answer for your question is heredity.
*September 5, 2014*

**math**

the mass of one red marble is 16g and you have 21 red marbles, therefore 16.21=336grams And you have 18 blue marbles and the mass of one blue marble is 20 grams therefore, 20.18=360g 336g+360g=696grams total in the box.. I hope my answer is correct.
*September 5, 2014*

**ALGEBRA**

for your second expression, you need to find 2 numbers that if you add or subtract will give you the middle term and if you multiply them, it will give you the last term. so going back to your example, the two number that if you multiply and they will give you (-14)is -7 and +...
*September 5, 2014*

**economics**

1) Give an example that you believe demonstrates when the cost of government actions outweighs the benefits.Identify the factors that may cause the costs of government actions to outweigh the benefits. I'm confused what does that mean? Thank you for your help!
*July 23, 2014*

**algebra**

The ratio of the lengths of strings that play the notes D and B (on a guitar), is 27 to 16. If a string 64 cm long plays B, what is the length of the string that plays a D?
*June 12, 2014*

**math**

The manager of a tea shop mixes two types of teas to make a specialty blend. Alone, the teas sell for $3.99 and $8.99 per ounce. How many ounces of each type of tea should be used to make 32 ounces of a mixture that sells for $5.99 per ounce?
*May 28, 2014*

**physics**

A steel (\alpha = 12 x 10^{-6} ^o C^{-1}) container with a volume of 548 {cm}^3 is filled with oil (\beta = 0.7 x 10^{-3} ^oC^{-1}). If the temperature is increased by 10^oC how much oil overflows? V_{spillage} =
*April 28, 2014*

**physics**

What is the total internal kinetic energy of 16.2 moles of a monatomic ideal gas at a temperature of 279 K? KE =
*April 28, 2014*

**physics**

A sound wave has a frequency of 1640 Hz. The air temperature is 46 degress F. What is the speed? v = What is the wavelenght of the sound? lambda =
*April 21, 2014*

**physics**

Water is in the big beaker in the figure on the left. Scale 1 reads 87 Newtons, scale 2 reads 544 newtons, and scale 3 reads 0 newtons. The hanging block has a density of 15 x 10^3 kg/m^3. What does scale 1 read after the block is fully lowered into the beaker of water? Scale...
*April 7, 2014*

**Physics**

Two objects with masses represented by m1 and m2 are moving such that their combined total momentum has a magnitude of 16.3 kg · m/s and points in a direction 71.5° above the positive x-axis. Object m1 is moving in the x direction with a speed of v1 = 2.84 m/s and ...
*March 2, 2014*

**math**

Sighting the top of a building, a surveyor measured the angle of elevation to be 60°. The measurement is taken 200 feet from the building. Find the building’s height. Express your answer in terms of feet and then round to two decimal places
*February 23, 2014*

**PHYSICS**

5. What is the maximum acceleration a car can undergo if the coefficient of static friction between the tires and the ground is 0.24? acceleration max=
*February 23, 2014*

**physics**

A -kg block is initially at rest on a frictionless horizontal surface. It is pulled with a constant horizontal force N. How long must it be pulled before its speed is m/s? t_{pull} =
*February 21, 2014*

**physics**

A block with a mass of 126 kg is pulled with a horizontal fource of F_{applied} across a rough floor. The coefficent of friction between the floor and the block is 0.7. If the block is moving at a constant velocity, what is the magnitude of F_{applied}? F_{applied} =
*February 21, 2014*

**physics**

Three blocks on a frictionless horizontal surface are in contact with each other. A force F is applied to block A and the blocks start to slide to the right of their initial position. Determine the acceleration of the system, if m_A = 12 kg, m_B = 38 kg, m_C = 4700 g, and F = ...
*February 21, 2014*

**Physics**

A physics book slides off a horizontal table top with a speed of 1.30 m/s . It strikes the floor after a time of 0.380s . Ignore air resistance. Find the height of the table top above the floor. Find the horizontal distance from the edge of the table to the point where the ...
*February 16, 2014*

**physics**

You are holding the neck of a champagne bottle at an elevation of 27 degrees when you pop the cork. The highest point in the cork's flight is 3.5 m above its initial height. What was the cork's initial speed? Use SI units in the second box.
*February 15, 2014*

**math**

The perimeter of a rectangular field is 300 meters. This field is to be fenced along three sides only. The fencing along its two lengths and one width is to be done at $50 per meter. If the total cost of fencing is $12,000, what are the field’s dimensions
*February 11, 2014*

**physics**

20.28792744 m/s thanks for nothing i solved it myself
*February 7, 2014*

**physics**

A ball is thrown straight upward from ground level. At what speed must the ball be thrown if it is to reach a maximum height 21 meters above the ground?
*February 7, 2014*

**Physics**

A 1500-kg car moving north at 27.0 m/s is struck by a 2165-kg car moving east at 13.0 m/s. The cars are stuck together. How fast and in what direction do they move immediately after the collision? 1. Degree north of east? 2. M/S?
*February 3, 2014*

**programming(visual basic)**

debugging exercise: Private Sub btnItemNumber_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnItemNumber.Click Dim decCost As Decimal Dim intCount As Decimal decCost = Convert.ToDecimal(txtCost.Text) Inventory(decCost, intCount) End Sub Private Sub...
*January 8, 2014*

**Math**

Select the x-coordinate of the vertex of the parabola defined by the function f(x) = -3x2 + 5x + 8.
*December 8, 2013*

**Algebra 8th**

1/2
*December 3, 2013*

**Statistics**

Determine the Null and Alternative Hypothesis for the following: A.) A company manufactures flares, they select 100 at random to determine if the flares last at least 3 hours on average. B.) A consumer group believes that a new sports coupe gets significantly less MPG than ...
*September 20, 2013*

**math**

The launch site for trigon balloon co. is 250 ft above sea level. A hot air balloon is launched from the site and begins to rise at a rate of 110 ft/min. At the same time, another balloon 2200 ft above sea level begins to descend at a rate of 150 ft/min. A. How long will it be...
*September 12, 2013*

**Physics**

If two protons and two neutrons are removed from the nucleus of an oxygen-16 atom, a nucleus of which element remains? Carbon 12 will be the answer, but i need to understand the answer. I requested help from a friend but was given the answer and not explained. I am having a ...
*August 28, 2013*

**chemistry**

A sample of naphthalene (C10H8) that has a mass of 0.7200 g is burned in a bomb calorimeter. The mass of the calorimeter is 1.580 kg, and its specific heat is 2.55 J/(g °C). As a result of the reaction, the temperature of the calorimeter increases from 22.00°C to 29.3&...
*August 22, 2013*

**chemistry**

The molar heat of fusion for water is 6.01 kJ/mol. How much energy must be added to a 75.0-g block of ice at 0°C to change it to 75.0 g of liquid water at 0°C? 1.44 kJ 10.18 kJ 12.48 kJ 25.04 kJ
*August 21, 2013*

**Math/Statistics**

A statistics teacher believes that the final exam grade for her elementary stats class have a normal distribution with a mean of 82 and a standard deviation on 8. Find the score which separates the top 10% of the scores from the lowest 90% of the scores.
*August 11, 2013*

**Algebra 1**

9 less than the product of 7 squared and a number is 6
*August 3, 2013*

**Math**

Kylee bought a pack of 12 cookies. Two thirds of the cookies are peanut butter. How many cookies in the pack are peanut butter?
*May 18, 2013*

**trig identities**

Find the exact value of cos (2theta) given csc theta = 8/3 and 0 < theta < pi/2
*May 8, 2013*

**mechanical/eginineering**

when a compound gear cluster is created how is the mechanical advantage calculated
*April 29, 2013*

**college physics**

how long would it take a 4.50kW MOTOR TO RAISE A 175KG BOILER TO A PLATFORM 15.0M ABOVE THE FLOOR?
*April 22, 2013*

**college physics**

How many seconds would it take a 7.00hp motor to raise a 475 lb boiler to a platform 38.0 ft high?
*April 22, 2013*

**Calculus**

Use logarithmic differentiation to find the derivative of the following: y=x^x^2 x>0 Please show all steps so I can following for future understanding
*April 21, 2013*

**Calculus**

Use logarithmic differentiation to find the following derivative y=(x+6)^4/(x-5)^6. Please show all steps so I can follow for future understanding. Thanks.
*April 21, 2013*

**Calculus**

Find the derivative of the following: f(x)=ln(e^(2x)/(x^2-4)^3 Please show all steps so I can follow Thanks!
*April 21, 2013*