# Posts by joseph

Total # Posts: 583

**Physics**

The Crab Nebula One of the most studied objects in the night sky is the Crab nebula, the remains of a supernova explosion observed by the Chinese in 1054. In 1968 it was discovered that a pulsar-a rapidly rotating neutron star that emits a pulse of radio waves with each ...

**Physics**

Pigeons are bred to display a number of interesting characteristics. One breed of pigeon, the "roller," is remarkable for the fact that it does a number of backward somersaults as it drops straight down toward the ground. Suppose a roller pigeon drops from rest and ...

**Physics**

Yo-Yo man releases a yo-yo from rest and allows it to drop, as he keeps the top end of the string stationary. The mass of the yo-yo is 0.056 kg, its moment of inertia is 2.9 X 10^-5 kg X m^2 and the radius r of the axle the string wraps around is 0.0064 m. Through what height ...

**AP macroeconomics**

Ok, I have a question. There is a production possibilities frontier graph (it's linear) labeled with 2 products that can be made on the axes for 2 sets of data regarding each person (rancher and farmer.) A point is labeled in the middle of the line of data that represents ...

**Math**

To a class of 28 pupils, 12 new pupils whose average age is 10 months less than the average age of the 28 are added. By how many months is the average age of the whole class lowered?

**Math**

To a class of 28 pupils, 12 new pupils whose average age is 10 months less than the average age of the 28 are added. By how many months is the average age of the whole class lowered?

**math**

6158.922795424538

**Chemistry**

How many moles of Fe2O3 are required to produce 38.4 moles of Fe?

**language arts**

Verb: :: zipcode:address

**Cypress**

Crystallization as a means to purify a compound fails when the resulting crystal formed is a cocrystal made up off your compound and an impurity. This may occur if the impurities present depict shapes that are complementary to those of the molecules that compose the desired ...

**geometry**

what is the perimeter of a square if both sides were 17 cm

**algebra**

THE FUNCTION D(X) MODELS THE CUMULATIVE NUMBER OF DEATHS FROM A DISEASE X YEARS AFTER 1984. ESTIMATE THE YEAR WHEN THERE WERE 90,000 DEATHS D(x)=2010X^2+5400X+5774

**English - Debate writting**

PLS I NEED POINTS TO WRITE THIS DEBATE. Write against the motion ' The use of mobile phones by second cycle institution boarding students is essential '.

**physics**

A car moves with an initial velocity of 25ms-1 and reaches a velocity of 45-1 in 10s. What is the acceleration of the car?

**COM**

WHATEVER!!!!!

**COM**

I just wrote this paper so I do not think it needs any changes. I was wanting someone to proof read it.

**COM**

What changes would you make to the below paper? The Dark Knight was the most popular film of 2008. Unlike most popular summer movies it was also considered to be a quality film and was thought to be a contender to earn an academy award nomination. Ultimately that honor was not...

**physics**

A reciprocating compressor is a device that compresses air by a back-and-forth straight-line motion, like a piston in a cylinder. Consider a reciprocating compressor running at 150 rpm. During a compression stroke, 1.30 mol of air is compressed. The initial temperature of the ...

**com**

why is the sequence of your paragraphs important in an essay

**calculus**

let m and b be nonzero real numbers if the line y=mx+b intersects y^2=4px in only one point, show that p=mb

**Life orientation**

Name two institutions/community organistations that are involved in supporting or giving redress to water pollution disasters.explain how these organisations are involved in providing a safe and healthy environment.

**COM**

Do you know of anything I have left out?

**COM**

Here is my answer so far. Do you know of anything else I can add to it?? The steps that must be taken prior to writing and effective persuasive essay is to build an outline of ideas and thoughts, elaborate those thoughts and ideas, do some research on the topic, define your ...

**COM**

Thank you for all the research!!

**COM**

What steps must be taken prior to writing an effective persuasive essay? How will those steps contribute to the effectiveness of your final paper?

**physics**

570J is the correct answer

**Science**

If one object on the moon weighs 42 pounds how much would it way on earth? Why?

**Physics**

In lab, a meter stick has its center of gravity at the 45.5 mark. The stick is supported with a meter stick clamp at the 25.0 mrk. A 3.500 kg mass is hung at the 18.2 cm mark to maintain rotational equilibrium. Whats is the calculation of the counterclockwise torque provided ...

**Com**

I did not understand your responce, could you please clarify?

**Com**

What is the rythem of the authors writing in the below paragraph? 3. Individuals can be denied credit for a number of reasons. Individuals who are near limits on existing cards, have too much outstanding debt or too many accounts overall, have a history of late payments, ...

**physics**

Believe it or not, a plumb-bob does not hang exactly along a line directed to the centre of the Earth! Determine how far off true plumb a bob hangs in Cape Town. In which direction is the deviation (north, east, south, or west)? How would your answer differ for a plumb-bob in ...

**algebra**

Make up a word problem that uses a quadratic function and requires finding either a maxiumum or minimum value.?

**English**

And if you were asked to write a principals report for class?

**English**

What is a principals report?

**Chemistry**

A student titrates HCl with 0.0125M KOH. Starting with 50.00 ml of the acid it takes 40.0 ml of base to reach equilavence point. A. What is the concentration of the HCl? B. What is the initial pH of the acid solution? C. What is the pH of the reaction mixture after the ...

**5 of 90 lotto equation formula**

pls i need number can repeat itself this week

**English**

Are there any compounds besides and,but,or,nor

**Chemistry**

A student titrates HCl with 0.0125M KOH. Starting with 50.00 ml of the acid it takes 40.0 ml of base to reach equilavence point. A. What is the concentration of the HCl? B. What is the initial pH of the acid solution? C. What is the pH of the reaction mixture after the ...

**Chemistry**

A student titrates HCl with 0.0125M KOH. Starting with 50.00 ml of the acid it takes 40.0 ml of base to reach equilavence point. A. What is the concentration of the HCl? B. What is the initial pH of the acid solution? C. What is the pH of the reaction mixture after the ...

**English - Debate writing**

Ms Sue pls i'm writing for the motion

**English - Debate writing**

I have a homework on debate on the motion 'The youth should be blamed for indiscipline in the society ' .Please help of to raise points for the motion .

**calculus**

solve the initial value problem by seperation of variables du/dt=2t+sec2t/2u, u(0)=-5

**chemistry**

Express your answer as a chemical equation. Identify all of the phases in your answer. H3PO + Sr(OH)2=

**math**

HOw can I find the domain and range of this problem 4x^3-39x^2+93.5

**2nd grade/math**

bhgb,jg,gbhhvhhhftyt

**Calc 2**

a) find the partial derivatives of each, and just plug in 1 for x and 3 for y (values should be close to 0)/ b) in using the difference quotients, take the limit as h approaches infinity of both each derivative, plugging in 0.1 for x and y in each one. It's better that you...

**Chem**

You are given pH which is (-log[H^+] ). so first you take 10^-2 to get the Molarity of [H^+], then you convert 500 mL to Liters so divide 500 by 1000. Finally you take Molarity times volume in liters to get moles of H^+. 10^-2 = .01 500/1000 = .5 .01 * .5 = 5*10^-3 = Moles of ...

**social studies**

what is an arch that forms a celling or roof

**social studies**

specific group that plundered rome. 5 letters.

**social studies**

the general term for a variety of groups who attacked roman towns

**social studies**

type of art made from tiny pieces of stone

**social studies**

what was the name of a hired soldier

**calc**

I would greatly appreciate your help with a math equation needed for a science experiment I'm researching. The case is the following: there is a pit full of juice and a stream of water is flowing through the pit (so that the amount of water which enters also exits). The ...

**math**

VALVE

**algebra**

ax/b + cx/d =e solve for variable x

**Physics**

Pa and Oz start walking at the same corner of a field whose south- west is bounded by a straight wall. Pa walks alongside the wall at 5.5 km/h while Oz sets off at 6 km/h along a straight foot path across the field which makes an angle of 50 degrees with the wall. Find the ...

**Chemistry**

Which of the following is(are) true for an exothermic reaction? [H = enthalpy] A) ƒ´H¢X > 0 B) ƒ´H¢X < 0 C) Hreactants > Hproducts D) Hreactants < Hproducts E) Hreactants = ƒ´H¢X The square means delta.

**English**

Thanks everyone i Got a 100% also!!! :) REAL ANSWERS ARE 1)c 2)a 3)c 4)a 5)a 6)c 7)d 8)d 9)a 10)c 11)a 12)a 13)c 14)c 15)d 16)d 17)c

**math**

what number gives the same result when multiplied by 6 as it does when 6 is added to it?

**Math**

The length of a rectangle is twice its width if the area of the rectangle is 200 m squared, find its perimeter.

**Physics**

100 m from a traffic light, a motorist sees it to red. If he needs to accelerate at -1 m.s ^2 to stop at the traffic light, what is the initial speed, and how long did he take to stop?

**Chemistry**

C=3 ;H=2 and Cl=1. Therefore the empirical formula of the compound is C3H2Cl The others don't seem clear to me

**Chemistry**

1) C=3 ;H=2 and Cl=1 so the empirical formula of the compound is C3H2Cl. I seem not to get the others clear.

**Physics**

A man using a 70 kg garden roller on a level surface exerts a force 20 kgf at 45 degrees to the ground . Find the vertical force of the roller on the ground if he ; a) pulls the roller. b) pushes the roller.

**Algebra-please check**

Thank you

**Algebra-please check**

Could someone please check my solution-Thank you-DRWLS helped me set it up and I solved it, I think From the top of a mountain 150 feet high, Jessie stands at the safety rail on the edge and looks below. The angle of elevation from his bike on the ground to Jessie is 38 ...

**Algebra II-please check**

sin 38 = .6157 .6157 = 150/x 150/.6157 = 243.6

**Algebra II**

From the top of a mountain 150 feet high, Jessie stands at the safety rail on the edge and looks below. The angle of elevation from his bike on the ground to Jessie is 38 degrees, how far is Jessie from his bike.Please help me to set this up Thank you

**Physics**

2 forces acting at a point make angles of 25 and 65 degrees respectively with their resultant which has a magnitude of 150 N .Find the magnitude of the two components.

**physics**

3 stings are attached on a ring. 2 of the strings make 70 degrees angle and each is pulled with 7.0 N . What force must be applied to keep the 3rd string to keep stationary?

**calculus**

At the instant when the radius of a cone is 3 inches, the volume of the cone is increasing at the rate of 28.27433388 cubic inches per minute. If the height is always 3 times the radius, find the rate of change of the radius at that instant?

**calculus**

find the inverse: y= ln (x/(x-1))

**Physics**

Given the info provided, this is a simple Q=mc(delta)T question. Simply plug and chug. m=10kg c=specific heat = 900j/kgxC (delta)T= 5 C The answer should be 4.5x10^4 J

**calculus**

the tangent line to the curve y=1/3(x^3)-3x^2+11x+15 is parallel to the line 9x-3y=2 at two points on the curve.Find the two points.

**Precalculus**

Doing some test corrections and not seeing this....Please help: Verify. csc^4x - cot^4x = 2csc^2x-1

**spanish**

Do you mean a la uno voy a la clase ciencias? If so, it means "at one o'clock I go to science class."

**Precalculus**

Having trouble with this: Verify: csc^4x-cot^4x=2csc^2x-1 *the numbers after the carets are to the power of

**Chemistry**

When a 1.350g sample of element X is heated in a stream of chlorine gas 6.67g of XCl3 are formed.1.) What(write) is a balance equation for the reaction using 'X' for the element? 2.) Calculate the atomic weight of X. 3.)What mass of X is left unreacted? 4.)When 1.00 ...

**Chemistry**

When a 1.350g sample of element X is heated in a stream of chlorine gas 6.67g of XCl3 are formed.1.) What(write) is a balance equation for the reaction using 'X' for the element? 2.) Calculate the atomic weight of X. 3.)What mass of X is left unreacted? 4.)When 1.00 ...

**physics**

Two identical containers are open at the top and are connected at the bottom via a tube of negligible volume and a valve which is closed. Both containers are filled initially to the same height of 1.00 m, one with water, the other with mercury, as the drawing indicates. The ...

**Statistics**

A student studies for a statistics exam where all questions are true or false. A reputable source indicates that with studying the student has a 90% chance of answering each question correctly. There are only three questions on the test. What is the probability that the ...

**Chemistry**

8.39g

**physics help**

ye i don't understand ho your explaining with the other guy who posted it. i don't know where you get any of your number from

**Physics help please**

The drawing shows a collision between two pucks on an air-hockey table. Puck A has a mass of 0.030 kg and is moving along the x axis with a velocity of +5.5 m/s. It makes a collision with puck B, which has a mass of 0.055 kg and is initially at rest. The collision is not head-...

**Physics please help cant figure this out**

im just not sure what formula exactly to use to solve each part a,b, and c

**Physics please help cant figure this out**

starting with an initial speed of 5.00 m/s at a height of 0.265 m, a 1.75 kg ball swings downward and strikes a 4.45 kg ball that is at rest, as the drawing shows. (a) Using the principle of conservation of mechanical energy, find the speed of the 1.75 kg ball just before ...

**physics please help**

for part a i got change in momentum right which was 1.8 then when i divided that by 4.05E-3 i got 4.44E-4 and it was marked wrong

**problem solving**

if a circuit has a 3.9k resistor and a 5/f capacitor find the current flow in the circuit at 0.005 seconds,if the maximum current flow in thecircuit is 1.5ma

**Science**

The normal boiling point for acetone is 56.5 Celsius. The atmospheric pressure is 630torr. What would be the boiling point of acetone, delta Hvap = 32.0 KJ/mol. What would be the vapor pressure of acetone at 25.0 Celsius. Please help me with this problem. Thank you

**Science**

BP -164°C ΔHvap 8.136 kJ/mol sg 2.205 J/g°C MP -182°C ΔHfus 0.928 kJ/mol sl 2.41 J/g°C Using the data above for methane, CH4, calculate the heat needed to convert 150. g of liquid methane at -175°C to a gas at 25°C.

**Science**

which of the following are predicted by the molecular orbital model to be stable diatomic species N22-, O22-, F22-

**Physics**

In a two-dimensional tug-of-war, Alex, Betty, and Charles pull horizontally on an automobile tire at the angles shown in the overhead view of the figure. The tire remains stationary in spite of the three pulls. Alex pulls with force of magnitude 226 N, and Charles pulls with ...

**Physics**

A 400 kg rocket sled can be accelerated at a constant rate from rest to 1600 km/h in 2.0 s. What is the magnitude of the required net force?

**science**

In defining the sizes of orbitals, why must we use an arbitrary value, such as 90 percent of the probability of finding an electron in that region?

**Science**

If you drive 20 laps around a circular race track at 100 m/s what do you know about your speed, velocity and acceleration?

**CHEMISTRY**

The first-order reaction, SO2Cl2 ¨ SO2 + Cl2, has a rate constant equal to 2.20 ~ 10-5 s-1 at 593 K. What percentage of the initial amount of SO2Cl2 will remain after 6.00 hours?

**chemistry**

The first-order reaction, SO2Cl2 ¨ SO2 + Cl2, has a rate constant equal to 2.20 ~ 10-5 s-1 at 593 K. What percentage of the initial amount of SO2Cl2 will remain after 6.00 hours?

**chemistry**

decomposition of H2O2 to water and O2

**chemistry**

why is temperature of H2O2 measured in the graduated cylinder?

**Math**

Simplify please...thnks X/50=(312-X)60