# Posts by Katie

Total # Posts: 2,096

**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

**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

**Civics**

I had this quiz. Thank you for the answers :) Hope they are right!

**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 ...

**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 × ...

**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?

**math**

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

**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 ...

**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?

**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 ...

**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...

**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...

**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%

**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

**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?

**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?

**3 questions~~~**

Thanks so much! I got 100% too!!!

**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).

**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.

**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) ...

**Chemistry**

The presence of ammonia in a solution of AgCl will decrease the solubility of AgCl. True Or False

**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

**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 ...

**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?

**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?

**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...

**physics**

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

**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 ...

**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 ...

**spanish - HELP!**

The answer is nos!

**AED**

Thank you very much.

**AED**

I'm guessing for all ages.

**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 ...

**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?

**CHEMISTRY**

What is the mass in grams of one Mole of water?

**Chemistry**

I believe it's 2.992x10^-23 grams... not sure

**Chemistry**

what is the mass in grams of one molecule of water?

**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?

**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?

**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.

**social studies**

i need to find if the answer to week to of my studies weekly

**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.

**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?

**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.

**chemistry**

there is a 2 a 2 not 1 but 2KClO3→ 2KCl + 3O2

**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

**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?

**chemistry**

I said 2KClO3

**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?

**Chemistry**

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

**Chemistry**

Really? My college professor marked it wrong on my work.. that's exactly what i had -_-

**Chemistry**

name the ions: Ag+ and P-3... and it's not silver..

**Chemistry**

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

**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?

**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?

**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 ...

**TN History**

Ive figured most out now, but i don't 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.

**TN History**

Im not sure. It did help the slaves, but the whites didn't handle it all that well... they formed the KKK and right after this, the Confederates changed laws. so im not too sure...

**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 ...

**Math**

9068

**English**

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

**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?

**math**

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

**physics**

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

**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?

**physics**

what is the propagation speed of a 5MHz transducer?

**physics**

The medium would be soft tissue. The speed in soft tissue is 1540 m/s.

**physics**

What is the wavelength of a 4MHz transducer?

**physics**

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

**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?

**Physics**

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

**Physics**

If the period of a transducer is 0.83msec, what is the HZ?

**physics**

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

**physics**

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

**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 ...

**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)?

**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...

**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?

**Algebra**

ok thanks

**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?

**someones GOTTA help me with this science...!!!**

1. B 2. A 3. C 4. D 5. A I'm in Connexus as well, and I got a 100% with those answers:)

**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?

**Science**

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

**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?

**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.

**science please check my answer**

How do I find the average acceleration of the ball?

**science please check my answer**

I got 57. 06 N, is that correct?

**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 ...

**science**

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? The bounce takes place over a 170 ms time interval. What is the impulse given to the ball during this time?

**Algebra**

Explain why n*0=0

**Math**

Write the equation of the line in standard form: (-3, 6); m = 1/2 (1, 0) & (-5, 3) Write the equation of the line perpendicular to 4x – 5y = -10 through the point(2, 3). Write the equation in slope intercept form.

**Math**

Write the equation of the line in slope intercept form: (4, 7); m = -3/8

**Math**

They all equal 3/4 cool thanks

**Math**

For the data in the table, does y vary directly with x? If it does, write an equation for the direct variation. X 52 = 32 = 20 = 8 Y 39 = 24 = 15 = 6

**Math**

Part 1: When writing linear equations, how do you determine which form of a line to use? Part 2: Choose 1 set of points from the choices below. Then, solve the problem and post your solution, showing your steps. Write an equation in point-slope form for the line that passes ...

**Math**

Find the range of each function for the given domain. 1. f(x) = -2x + 1; {-6, -2, 0} 2. f(x) = x3 + 1; {-2, -1, 3}

**Algebra**

Help Please Write a function rule that represents each sentence. 1. 11 less than the product of a number y and -2 is z. 2. 5 less than the quotient of a number n and 4 is m.

**chemistry**

1- A compound is 87.5% nitrogen and 12.5% hydrogen. The molecular weight of the compound is 32 g/mol. Describe the molecule referencing shape, and inter-molecular forces. 2- Gaseous butadiene, C4H6 , reacts with hydrogen gas in the presence of a platinum catalyst to form ...

**chemistry**

Consider the following reaction: CH3X + Y CH3Y + X At 25oC, the following two experiments were run, yielding the following data: Experiment 1 : [Y]0 = 3.0 M [CH3X] Time(hr) 7.08 x 10-3M 1.0 4.52 x 10-3M 1.5 2.23 x 10-3M 2.3 4.76 x 10-4M 4.0 8.44 x 10-5M 5.7 2.75 x 10-...

**science**

They are not here to help you cheat