Friday

October 24, 2014

October 24, 2014

Total # Posts: 1,679

**physics **

A line directed to the west. A plane flies 20 degrees north of that direction ( 90 degrees north of that direction would be north..) if the plane flies for 340 km, determine its displacement toward the west and its displacement toward the north during its flight?
*October 23, 2014*

**math**

The Murphy family just drove 300 miles to visit their grandparents. Mr. Murphy drove 70 mph for 65% of the trip and 35 mph or less for 20% of the trip that was left. Assuming that Mr. Murphy never went over 70 mph, how many miles did he travel at a speed between 35 and 70 mph...
*October 22, 2014*

**Chemistry**

thank you very much!
*October 16, 2014*

**Chemistry**

oh I mean, is 3 a heterogeneous reaction, not 3a. But a gas and an aqueous is a heterogeneous reaction correct? Thanks!
*October 16, 2014*

**Chemistry**

Increasing the surface area will increase the reaction rate in: 1. N2(g) + O2(g) -> 2NO(g) 2. 2Mg(s) + O2(g) -> 2MgO(s) 3. CaCO3(s) + 2H+(aq) -> Ca2+(aq) + H2O(l) + CO2(g) MY WORK: I think it is 2 & possibly 3. 1 is a homogeneous reaction but is 3 a heterogeneous ...
*October 16, 2014*

**Physics**

A car accelerates from rest at 5 m/s2 for 5 seconds. It moves with a constant velocity for some time, and then decelerates at 5 m/s2 to come to rest. The entire journey takes 25 seconds. On a separate sheet of paper, plot the velocity-time graph of the motion. Describe the ...
*September 30, 2014*

**Physics**

You want to use a rope to pull a 12-kg box of books up a plane inclined 30∘ above the horizontal. The coefficient of kinetic friction is 0.29. The rope pulls parallel to the incline. What force do you need to exert on the rope if you want to pull the box with a constant ...
*September 30, 2014*

**college physics**

tennis ball rolls off the edge of a tabletop 0.900m above the floor and strikes the floor at a point 1.60m horizontally from the edge of the table. A: Find the time of flight of the ball B: Find the magnitude of the initial velocity of the ball. C: Find the magnitude of the ...
*September 22, 2014*

**Algebra 1**

the temperature at noon in los angeles on a summer day was 88 degrees fahrenheit. during the day, the temperature varies from this by as much as 7.5 degrees fahrenheit. write and solve an absolute-value inequality to find the range of possible temperature for that day.
*September 11, 2014*

**geometry**

ABCD is a rhombus with diagonals Imported Asset and Imported Asset . Is angle ABD congruent to angle CBD?
*July 7, 2014*

**ashford**

Ruby emailed her instructor a question and he replied to her immediately.
*July 2, 2014*

**math**

That helped. Thankyou Ms.Sue
*June 11, 2014*

**math**

a 15 foot ladder is leaning against a house with the base of the ladder 4 feet from the house. How high up the house does the ladder reach? round to the nearest tenth foot.
*June 11, 2014*

**math**

What is the period, in seconds, of a simple pendulum of length 3 meters? Use the gravitational constant g = 9.8 m/s2 and round your answer to two decimal places Please help! A step by step would with the answer would be helpful!
*June 9, 2014*

**Pre-Calc**

2. The polar coordinates of a point are given. Find the rectangular coordinates of each point. a. (5,(π / 4)) b. (-2,(π / 6)) NOTE: I tried to do these myself and got that: a= (4.99,0.27) b=(-1.99,-0.11) Which I know these are wrong, so I don't know how to do ...
*June 7, 2014*

**Chemistry**

A solution of the primary standard potassium hydrogen phthalate, KHC8H4O4, was prepared by dissolving 0.4877 g of potassium hydrogen phthalate in about 50 mL of water. Titration with a KOH solution required 24.71 mL to reach a phenolphthalein end point. What is the molarity of...
*June 6, 2014*

**science**

A rock tumbles straight down from a cliff, its moving at 20 m/s when it hits. What is the height of the cliff? The mass of the rock is 8 kg. a) 2.5 m b) 400 m C) 20.4 m d) 160 m
*May 23, 2014*

**physics**

A subcompact car, mass 1,000 kg, runs into and sticks to an at rest, 2,200 kg SUV. If their final speed is 4.7m/s ,what was the smaller cars initial speed? a) 67 m/s b) 30m/s c) 2.2 m/s d) 15 m/s
*May 23, 2014*

**FInite Math**

A car rental agency has rental and return facilities at both Dallas and Austin Airports. Assume that a car rented at either airport must be returned to one or the other airport. If a car is rented at Austin, the probability that it will be returned there is .80; If a car is ...
*May 6, 2014*

**General Chem 2**

Given: Al3+(aq) + 3e– --> Al(s); E° = –1.66 V I2(s) + 2e– --> 2I–(aq); E° = 0.54 V What is ∆G° for the following cell reaction? 2AlI3(aq) --> 2Al(s) + 3I2(s) A) 4.2 × 105 J B) –6.5 × 105 J C) –1.3 × ...
*May 3, 2014*

**algebra**

George has 25 marbles. he wants to divide them into two amounts hat show a ratio of 2:3 how many marbles are in each group?
*April 27, 2014*

**math**

determine the intervals for which the curve r(t)=4sin^3(t)i+7cos^3(t)j is smooth on [0,2π
*April 27, 2014*

**Stats Class HELP!**

Twenty-five blood samples were selected by taking every seventh blood sample from racks holding 187 blood samples from the morning draw at a medical center. The white blood count (WBC) was measured using a Coulter Counter Model S. The mean WBC was 8.636 with a standard ...
*April 18, 2014*

**Stats. Class**

a. What sample size would be needed to estimate the true proportion of students at your college who are wearing backpacks, with 95% confidence and and error of +/-0.04? b. What sampling method would you recommend? Why?
*April 18, 2014*

**Stats Class**

The EPA city/hwy mpg range for a Saturn Vue FWD automatic 5-speed transmission is 20 to 28 mpg. If you owned this vehicle, how large a sample (e.g. how many tanks of gas) would be required to estimate your mean mpg with an error of ±1 mpg and 90% confidence? Explain ...
*April 18, 2014*

**statistics**

It is known that the population mean for the Full Scale IQ of the WAIS is 100 with a standard deviation of 15. A researcher assesses a sample of 200 adults and find that they have a mean Full Scale IQ of 102. The point estimate of the mean for this group is ___________ and the...
*April 15, 2014*

**statistics**

It is known that the population mean for the Full Scale IQ of the WAIS is 100 with a standard deviation of 15. A researcher assesses a sample of 200 adults and find that they have a mean Full Scale IQ of 102. The point estimate of the mean for this group is ___________ and the...
*April 15, 2014*

**statistics**

Which of the following percentiles corresponds to the area beneath the standard normal curve from a z score of-3.00 to + 3.00? a. 98% b. 100% c. 95% d. 99.7%
*April 15, 2014*

**statistics**

Jorge finds that his standardized z score on an IQ is 2.0. What percentage of people did he score higher than? a. 98 b. 96 c. 68 d. 34
*April 15, 2014*

**math**

A jar of coins has only nickels and quarters, which are worth a total of $3.25. There are 5 fewer quarters than nickels. How many quarters and nickels are in the jar?
*April 14, 2014*

**Chemistry**

Based on the mechanisms that you have determined and the information in the introduction, what is the product of 1-cholorobutane after reaction under the sodium iodide conditions? The ethanolic silver nitrate conditions?
*April 14, 2014*

**9th grade math**

Ok, trent, so if solving for m use this formula: (Google quadratic formula to see formula) so, -b should be 24, b^2 should be -24^2, a should be 4 and c should be 36. The answer should be m=3. -------But if you are to foil this, then 4m^2-24m+36 will be (4m-12)(m-3).
*April 8, 2014*

**Chemistry**

For a reaction that has an equilibrium constant of 9 × 10–9, which of the following statements must be true? A) ∆G° is positive. B) ∆G° is negative. C) ∆H° is negative. D) ∆H° is positive. E) ∆S° is positive.
*April 6, 2014*

**Chemistry**

The standard enthalpy of fusion of iodobenzene is 9.75 kJ/mol at its melting point, 241.8 K. What is the standard change in entropy for the melting of iodobenzene at its melting point? A) –9.75 J/(mol • K) B) –311 J/(mol • K) C) 0.0403 J/(mol • K) D) ...
*March 31, 2014*

**Chemistry**

The presence of ammonia in a solution of AgCl will decrease the solubility of AgCl. True Or False
*March 31, 2014*

**physics**

is it d = 1/2 (9.8) (3)^2 = 44.1 m/s^2/3s =14.7 m/s x 2 = 32.87 = 32.87 mi/h? and b) d= 1/2 (9.8) (3)^2 =44.1 m/s^2/35 = 14.7 m/s
*March 30, 2014*

**physics**

a student drops an object out the window of the top floor of a high-rise dormitory a) neglecting air resistance, how fast is the object traveling when it strikes the ground at the end of 3.0 s? express the speed in mi/h for a familiar comparison, b) how far, in meters, does ...
*March 30, 2014*

**physics**

does this change the answer... the ball is dropped from the top of an 80-m-high building. does the ball reach the ground in 4.0 s? I got no, it falls only 78 m in 4.0 s What speed does the ball in the first question have in falling 3.5 s?
*March 30, 2014*

**physics**

a ball is dropped from the top on an 80-m high building. what speed does the ball have in falling 3.5 s?
*March 30, 2014*

**physics**

a car travels on a straight road. a) starting from rest, the car is going 44 ft/s (30 mi/h) at the end of 5.0 s. What is the car's average acceleration in ft/s^2 b) in 4.0 more seconds, the car is going 88 ft/s (60 mi/h). what is the car's average acceleration for this...
*March 30, 2014*

**physics**

why is it not 30-0/20=1.5 and 5/20=4 km/min = 4,000 m/min = 66.67 m/s?
*March 30, 2014*

**physics**

modern oil tankers weigh more than a half-million tons and have lengths of up to one-fourth mile. Such massive ships require a distance of 5.0 km (about 3.0 mi) and a time of 20 min to come to a stop from a top speed of 30 km/h. What is the magnitude of a such a ship's ...
*March 30, 2014*

**physics**

a race car traveling northward on a straight, level track at a constant speed travels 0.750 km in 20.0 s. the return trip over the same track is made in 25.0 s. a) what is the average velocity if the car in m/s for the first leg of the run? b) what is the average velocity for ...
*March 30, 2014*

**spanish - HELP!**

The answer is nos!
*March 25, 2014*

**AED**

Thank you very much.
*March 20, 2014*

**AED**

I'm guessing for all ages.
*March 20, 2014*

**AED**

As we analyze Western thought vs. Eastern thought, we also should take a look at the application of each school of thought is applied. Lets say that American schools reform to include eastern philosophy in its curriculum. What steps would have to occur to prepare our students ...
*March 20, 2014*

**please answer this one..**

what is the mass in grams of one molecule of water... and is this one different from what is the mass in grans of one mole of water?
*March 19, 2014*

**CHEMISTRY **

What is the mass in grams of one Mole of water?
*March 19, 2014*

**Chemistry**

I believe it's 2.992x10^-23 grams... not sure
*March 19, 2014*

**Chemistry**

what is the mass in grams of one molecule of water?
*March 19, 2014*

**physics **

The angle of incidence and the angle of refraction for light going from air into a material with a higher index of refraction are 69.9° and 39.6°, respectively. What is the index of refraction of this material?
*March 18, 2014*

**Math**

A kite that is 7 feet tall casts a shadow that is 4 feet long. How long would the shadow be if a kite is only 4 feet tall?
*March 18, 2014*

**Chemistry**

A student has 600.0 mL of a 0.30M solution of HNO3. How much water must she add in order to make it a 0.15 M solution? Be careful how this question is answered.
*March 14, 2014*

**math**

A box contains only quarters and dimes. If there 10% more quarters, the total value of the money in the box would increase by 7.5%. What is the ratio of the number of quarters and dimes in the box? Express your answer as a common fraction.
*March 4, 2014*

**math**

Mrs. Marcincavage allowed each student in her math class to drop the lowest of their five test scores. When Matthew dropped the lowest of his test scores, a 60, his test average increased by 5 points. What is Matthew’s new test average?
*March 4, 2014*

**math**

A box contains only quarters and dimes. If there 10% more quarters, the total value of the money in the box would increase by 7.5%. What is the ratio of the number of quarters and dimes in the box? Express your answer as a common fraction.
*March 4, 2014*

**chemistry**

there is a 2 a 2 not 1 but 2KClO3→ 2KCl + 3O2
*March 1, 2014*

**chemistry**

when magnesium chlorate under goes decompostion, oxgen gas is realsed in the following reaction: 2KClO3→ 2KCl + 3O2 repeat 2KClO3→ 2KCl + 3O2 when 3.50 grams of potassuim chlorate is decomposed at STP, how many litters of oxgen will be produced? chemistry - Da
*March 1, 2014*

**chemistry**

magnesium chlorate under goes decompostion, oxgen gas is realsed in the following reaction: 2KClO3 → 2KCl + 3O2 when 3.50 grams of potassuim chlorate is decomposed at STP, how many litters of oxgen will be produced?
*March 1, 2014*

**chemistry**

I said 2KClO3
*March 1, 2014*

**chemistry **

when magnesium chlorate under goes decompostion, oxgen gas is realsed in the following reaction: 2KClO3→ 2KCl + 3O2 when 3.50 grams of potassuim chlorate is decomposed at STP, how many litters of oxgen will be produced?
*March 1, 2014*

**Chemistry**

Oh, alright. thanks though x)least i know im not the only one missing something
*February 24, 2014*

**Chemistry**

Really? My college professor marked it wrong on my work.. thats exactly what i had -_-
*February 24, 2014*

**Chemistry**

name the ions: Ag+ and P-3... and it's not silver..
*February 24, 2014*

**Chemistry**

How many grams of AL(NO3)3 are produced when 23.5 grams of Aluminum react with 133 mL of 6.5M HCL?
*February 23, 2014*

**Chemistry help**

A ground state hydrogen atom absorbs a photon of light having a wavelength of 93.77 nm. It then gives off a photon having a wavelength of 94 nm. What is the final state of the hydrogen atom?
*February 20, 2014*

**College Algebra**

A ball is thrown upward with an initial velocity of 48 ft/sec from a height 640 ft. Its height h, in feet, after t seconds is given by h(t)=-16t^2+48t+640. After how long will the ball reach the ground?
*February 20, 2014*

**Chemistry**

At noon on a clear day, sunlight reaches the earth\'s surface at Madison, Wisconsin, with an average power of approximately 7.00 kJ·s–1·m–2. If the sunlight consists of photons with an average wavelength of 510.0 nm, how many photons strike a 8.40 ...
*February 19, 2014*

**TN History**

Ive figured most out now, but i dont know how the state government in tn restore after the reconstruction era.. any book or website that would help answering this. ive tried for a while now and im not making any progress with this one single question.
*February 18, 2014*

**TN History**

Im not sure. It did help the slaves, but the whites didnt handle it all that well... they formed the KKK and right after this, the Confederates changed laws. so im not too sure...
*February 18, 2014*

**TN History**

how well did Tennessee deal with the four issues of Reconstruction; the status of its former Confederates, the restoration of the state government, economic reconstruction, and the status of former slaves? (Just one sentence would help me a lot... i know a lot of info but not ...
*February 18, 2014*

**English**

What resource whether its online etc can LGBT community support, how can they get help? Thanks!
*February 15, 2014*

**physics **

A stereo speaker represented by P in the figure below emits sound waves with a power output of 114 W. What is the intensity of the sound waves at point x when r = 11.8 m?
*February 12, 2014*

**math**

What is the approximate circumference of a pizza pan with a diameter of 13.2 inches? (Use π = 3.14)
*February 5, 2014*

**physics**

The wavelength of a pulse is 0.1925mm. There are 5 cycles in the pulse. What is the spatial pulse length?
*February 5, 2014*

**physics**

The pulse duration of the transducer is 0.6 microseconds. The frequency of the transducer is 8MHz. How many cycles are contained in that pulse?
*February 5, 2014*

**physics**

what is the propagation speed of a 5MHz transducer?
*February 5, 2014*

**physics**

The medium would be soft tissue. The speed in soft tissue is 1540 m/s.
*February 5, 2014*

**physics**

What is the wavelength of a 4MHz transducer?
*February 5, 2014*

**physics**

Yes, all my questions are for ultrasound physics. I should've mentioned that, sorry. Thanks for the help
*February 5, 2014*

**physics**

If an ultrasound beam at the focal zone has a power of 0.050 watts and the area at this focal zone is 4cm^2, what is the intensity of the beam?
*February 5, 2014*

**Physics**

I know the formulas, just having problems with the right units. I got 1205 Hz for this one????
*February 5, 2014*

**Physics**

If the period of a transducer is 0.83msec, what is the HZ?
*February 5, 2014*

**physics**

so would it be 0.2 microseconds? I just want to make sure I am understanding it correctly, with the correct units, thanks
*February 5, 2014*

**physics**

If the frequency of a transducer is 5MHz, what is the period?
*February 5, 2014*

**Chemistry**

The FDA recommends that women who are pregnant avoid eating more than three 6.00-oz servings of bluefish per month because of the relatively high mercury levels in that type of fish. If bluefish contains 0.341 ppm of mercury (that is, 0.341 oz of mercury per 1×106 oz of ...
*February 1, 2014*

**Chemistry**

An office heater puts out 2070 Btus (British thermal units) of energy in the form of heat per hour. Given that 1 Btu = 1.055 kJ, how many megajoules of energy in the form of heat can be produced per year (365 days) by the heater (assume continuous operation)?
*February 1, 2014*

**physics**

the total electric field e consists of the vector sum of two parts. one part has a magnitude of e1 = 1284 n/c and points at an angle θ1 = 30° above the +x axis. the other part has a magnitude of e2 = 1833 n/c and points at an angle θ2 = 62° above the +x axis...
*January 31, 2014*

**Chemistry**

A particular MP3 encoder can convert 79.0 kilobytes (kb) of music per second from a typical music CD. How many minutes will it take to convert 13.3 megabytes (Mb) of music from a CD?
*January 29, 2014*

**Algebra**

ok thanks
*January 22, 2014*

**Algebra **

Jena wants to paint the walls in her square shaped bedroom. each wall has an area of 130 sq ft. if one quart of paint covers 150 sq ft, how many quarts of paint will she need to buy to paint all four walls? Would I leave it 4.6 or round up to five quarts?
*January 22, 2014*

**physics**

How long will it take a sample of polonium-210 with a half-life of 140 days to decay to one-sixty-fourth of its original strength?
*January 15, 2014*

**Science**

I mean I would like to know how to work it out and not just get the answer but thanks for the help.
*January 14, 2014*

**Science**

What is the radius in nm of the electron orbit of a hydrogen atom for n=3? What is the radius in nm of the electron orbit of a hydrogen atom for n=4?
*January 14, 2014*

**math**

A florist had an equal number of red and yellow tulips. She sold 624 red tulips. Then she had 4 times as many yellow tulips as red tulips. How many tulips did she start with? You must use a bar model to solve this problem.
*January 12, 2014*

**science please check my answer**

How do I find the average acceleration of the ball?
*January 11, 2014*

**science please check my answer**

I got 57. 06 N, is that correct?
*January 11, 2014*

**science please check my answer**

A boy climbs to the roof of his house and drops a 0.40 kg rubber ball from the 7.5-meter peak of the house. How much energy was lost in the process? So I got 48 J is this correct? The bounce takes place over a 170 ms time interval. What is the impulse given to the ball during ...
*January 11, 2014*

Pages: **1** | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | Next>>