# Posts by Joe

Total # Posts: 2,732

physics
PE=(13/3)k(Q^2)/a

Math
Solve by the elimination method. 2r-5s = -11 5r + 2s = 16

Math
Find the indicated outputs for f(x)= 5x^2-5x. F(0) = 0 f(-1)= 1 f(2)= 45 is this right?

Elimination Method...
Solve by eliminatin method. 2r-5s= -11 5r+2s= 16

equal group riddles
i am a number between 20 and 30.when you put me into 6 equal groups;there is an even number in each group and 1 is left over.what number am i

Finance
2142

math
In how many ways can 7 basketball players of different heights line up in a single row so that no player is standing between 2 people taller than she is?

chemistry
22%

Algebra
69

Math-Fractions
How would I solve these two problems. (We have to simplify our answer) 5/7 divided by 8/21 12/7 divided by 9/21

Elementary Math
On a number where would 4/3 go? Would it go one third the way between 3 and 4? Where would 5/3 go?

Molarity
Determine the molarity and normality of a solution prepared by dissolving 55 mg of sodium bicarbonate (NaHCO3) in 750 mL of water.

Precal
use graphic techiques in radians I found that it is roughly equal to -.5 sin [ 20.42036^-1(x + 40.84071)pi ] + 1

Precal
I do not understand how to do this problem ((sin^3 A + cos^3 A)/(sin A + cos A) ) = 1 - sin A cos A note that all the trig terms are closed right after there A's example sin A cos A = sin (A) cos (A) I wrote it out like this 0 = - sin^6 A - cos^6 A + 2sin^3 A cos^3 A - ...

Physics
I'm having some trouble with this question A 4200-kg rocket is traveling in outer space with a velocity of 120m/s toward the Sun. It needs to alter its course by 23 degrees, which can be done by shooting is rockets briefly in a direction perpendicular to it’s original...

Physics
A 16.0 - kg descends a slide 2.50 m high and reaches the bottom with a speed of 2.25 m/s. How much thermal energy due to firciton was generated in the process? for this I keep on getting 432.5 J but the back of the book tells me that the answer is 352 J and I do not see how to...

physics
A charge of 2.4 nC and a charge of 5.0 nC are separated by 33.30 cm. Find the equilibrium position for a -4.1 nC charge.

physics
Calculate the net charge on a substance consisting of a combination of 6.8 multiplied by 1013 protons and 4.6 multiplied by 1013 electrons.

precal
given cscx= -3 and tanx>0 find cosx

precal
from {0,2pie} what are the solutions of tan x/4= square root of 3/3

precal
from {o, 2pie} what are the solutions of cos(squared)x- cos2x=0

urgent precal
What is cosx/ (secx-1) not in fractional form?

precal
yes i meant to have it with parantheses

precal
rewrite cosx/secx-1 not in fractional form

chemistry
In any chemical reaction, the quantities that are preserved are what? A. the number of moles and the volumes B. the number of molecules and the volumes C. mass and number of atoms D. mass and moles

AP World History
How can I show Change and Continuity in the American Environment between 600 AD - 1750 AD?

Biology
the first one is b. there is no general relationship.

Math
A group of nine students has a mean of 3.5 people in their households. Make a line plot showing an example of this data set

science
When is the Earth farthest from the sun?

How do I figure out answer

Physics
The Olympic diver completes 3.5 somersaults in 1.7 seconds. What is the average angular speed (in rad/s) of the diver?

chemistry
The addition of a dilute hydrobromic acid would clearly distinguish solutions of a. barium nitrate and sodium sulfate b. lead nitrate and silver nitrate c. mercury(I) nitrate and silver nitrate d. silver nitrate and calcium sulfate e. calcium nitrate and barium nitrate

AP Physics B (Heat Engines)
I know that efficiency is e = |W|/|QH| were the H is the subscript I know that 900 MW is a value of power which is not work I know that |QH| is 2.8 E8 J/kg but I do not like the units for this, J/kg, as I thought Q was measured in joules only... How do I find the work done?

AP Physics B (Heat Engines)
18. (II) At a steam power plant, steam engines work in pairs, the heat output of the first one being the approximate ehat input of the second. Th eoperating temeprautres of the first are 680 degrees C and 430 degrees C, and of the second 415 degrees C and 280 degrees C. If the...

pre al
how do you find surface area

SCIENCE
What is the movement of a water particle in a wave called?

science
The movement of a water particle in a wave is called what?

physics
An aluminum cylinder weighs 1.03 N. When this same cylinder is completely submerged in alcohol, the volume of the displaced alcohol is 3.90 x 10-5 m3. If the cylinder is suspended from a scale while submerged in the alcohol, the scale reading is 0.730 N. What is the specific ...

History
Why do we need taxes? Could someone tell me in two paragraphs besides that we need it for roads and schools

college
what strategies can be incorporate into effective visual element into business presentations

algebra 1
Use the point-slope form to write an equation of the line with the given slope and point. m = 4, passes through (4, 6)

PreCalc
please h t t p : / / w w w . j i s k h a . c o m / d i s p l a y . c g i ? i d = 1 2 6 0 4 8 7 4 9 0

Pre Calc
I do not see why I got two different equations for my answer A weight attached to the end of along spring is bounicng up and down. As it bounces, its distance from the floor varies sinusoidally with time. You start a stopwatch. When the stopwatch reads 0.3 s, the weight first ...

biology
what functional groups appear in CH3CH2CH2Br

algebra
3[5-(2x+1(2))]= 3[5-(2x+2)] 3[5-2x-2]= 3[3-2x]= 9-6x

spanish
what is the correct possessive adjective for ¿Es mi clase de español?

english
Did you like “Usher”? How successful was Poe’s use of Gothic devices in creating an atmosphere of dread?

Calc 3
The actual span of the base of the dome is 143 feet. 1) Use cylindrical coordinates to write the surface of the dome as a function of the distance from the center of the base; that is find z = f (r) . 2) Use your function to find the height of the dome; that is what is f (0...

Pre Calc
Naturalists findthat the populations of some kinds of predatory animals vary periodically. Assume that the population of foxes in a certain forext vareis sinusoidally iwth time. REcord started being kept when time t = 0 years. A minimum number, 200 foxes, occurred when t = 2.9...

PreCalc
never mind

PreCalc
so what is the equation of the line??? h t t p : / / w w w . j i s k h a . c o m / d i s p l a y . c g i ? i d = 1 2 6 0 1 4 7 1 4 4 I understood this y = 120 + 8sin((pi)/35 - (5pi)/4)=120 were do i go from here THANKS!!!

Math
What does this notation mean =^-1 equal sign raised to negative one power

TOBOBPURSLEY
I thought phase shift was theta over omega correct??? and the period equals two pi over omega 40 min = (2pi)/omega omgea = pi/20 min phase shift = theta over omega phase sift = (20?)/pi min now you said phase shift was (35 pi)/40 I do not see why I appologize i made a spelling...

TOBOBPURSLEY
how do we now that the phase shift is (35pi)/40 please explain THANKS

PreCalculus
I have a question I do not think anybody answered it Researches find a creature form an alienplanet. Its body temperature is varying sinusoidally with time. 35 min after they start timing, it reaches a high of 120 F. 20 min after that it reaches its next low, 104 F. How do I ...

PreCalculus
How do i find the phase shift in this problem Naturalists find that the populations fo some kinds of predatory animals vary periodically. Assume that the population of foxes in a certain forest varies sinusoidally with time. Records started being kept when time t = 0 years. A ...

how did the survivours of Krakatoa receive help

FINANCE
go on th eenternet

Precalculus
tangent theta is equal to the derivative of sine theta over the derivative of cosine theta?

Precalculus
Sorry ok I was talking about on the unit circle how come the slope of the reference line (say if you were to angle pi/2, the reference line would be the positive y axis from y equals zero to y equals one, I think this line is called this, like if you were to draw pi/4 on the ...

PreCalculus
h t t p : / / w w w . j i s k h a . c o m / d i s p l a y . c g i ? i d = 1 2 5 9 7 1 4 6 2 0

PreCalculus
Ok I know that the slope of a straight line is the same thing as x with a dot aboce it or simply the first derivative of x on the unit circle tangent gives you the slope of the reference line right? This can be expressed using the notation expressed above but how? Thanks!

physics
On a cold winter day when the temperature is -20 degrees celsius, what is the amount of heat needed to warm internal body temp(37) the .5 L of air exchanged with each breath? Specific heat of air is 1020 J/(kg K) and that 1.0L air has a mass of 1.3g. Please help!! I don't ...

Statistics (Probability)
I have a q

Psychology
its my friend, we both have the same problems and try to see if we can get helped

Psychology
Could someone see if I got any of the questions wrong. I feel that some questions have multiple answers but there is only one that is correct. Please help. thanks a lot State whether each scenario is an example of assimilation or accommodation. 1. A child has always used a ...

chemistry
a resting person requires 14.5 L of O2 per hour to maintain metabolic activities. Such a person breathes in 0.50 L of air at approximately 20 degrees C with each breath. The inhaled air is 20.9%O2 while the exhaled air is 16.3% O2. (a) how many breaths per minute does a ...

math
1/n^2=0.0278

Networking
Jack is setting up a new FTP server that is running the Windows XP operating system. This FTP server will be shared by seven different corporate departments, each identified by a user group, but access is to be restricted by department. The Domain Administrators, Departmental ...

Math
some of the worst math I've ever seen

Physics
141.39m = R R = ((vi)^2 * sin(2 theta))/gravity

Calc
A common inhabitant of human intestines is the bacterium Escherichia coli. A cell of this bacterium in a nutrient-broth medium divides into two cells every 20 minutes. The initial population of a culture is 59 cells. (The tolerance is 1% unless your instructor states otherwise...

algebra
A wholesaler mixed coffee beans worth \$6/kg with another kind worth \$8.80/kg. The 16kg mixture was worth \$6.70/kg. How many kilograms of each type was used?

1.i and 5 2.named and blaze 3.was and once 4.wouldn't and out 5.first and filly 6.hoarse and croaked

Physics
Projectile motion equation: y=xtan(è)-(gx^2)/[2(ucos(è))^2] where è=39.5 deg., u -34.9 met/sec & g=9.8 met/sec^2. On substitution and solving for y=0, you can get the horizontal range as 122.003 met. and thus the time required would be = 122.003/(ucos(&...

English
i think you sohould either try and find online video interviews of this per, and as cheesy as its sounds imagen you are the one asking the questions and tehy are responding to you then give your opinions on their answers. ps if you cannot find someone with online videos ...

math
it depends on the amount of ppl who would win and

math
it depends on the amount of ppl who would win

Chemistry
your teacher should give you a chart with which elements are soluble and insoluble

tutor period
what is a blog and how do you write one

albebra
c=2*3.14sqare root

College mechanic vibration
Estimate and discuss the maximum bouncing and pitching generated by your design when the car travels at 40 km/hr over a rugged terrain roughly modeled by a sine wave with 0.10 meter amplitude and 4.0 meter period. (This one does not have to be an accurate calculation. State ...

math
thanks :) that helped

math
Give the Five-Number Summary for this data set. Round your answers to the nearest tenth. 18, 22, 36, 36, 36, 44, 185, 304, 24

graphic design
the purpose of an art is to provide visual appeal. true or false

social studies
what is the geography of the great barrier reef

What did the spanish farmer say to his chicken

Calc
This is a very confusing problem for me y = 5^3^x^2 Find y'

Probability
Given additional information that 56% of the total employees in the company are male and 50% of them are employees who have been working less than 5 years. If an employee selected at random is known to have been working for 5 years or more, what is the probability that the ...

Physics
no idea all HELP appreciated!! A shot-putter puts a shot (weight = 70.3 N) that leaves his hand at distance of 1.45 m above the ground. (a) Find the work done by the gravitation force when the shot has risen to a height of 2.15 m above the ground. Include the correct sign for ...

science
you push yoursef on a skateboard with the force o 30n and the accelerate at 0,5m/s2 find the mass of you and the skateboard together

science
find the force exerted by z rope on a 10kg mass that is hanging from the rope

accounting
preent in journal form adjusting entries that would be made on july 31,2011 the end of the fiscal year 1. apr 30, a ten month 9% note for \$20,000 was received from a customer

Computers
I have a question. What should you set your margins to if you want to print out your notes and glue them to a 3 x 5 notecard?

Math
Out of the numbers divisible by 3, we picked 4 consecutive numbers. To the sum of these, we added a third of the sum, and then the half of the third of the sum. We got 225. What are those 4 numbers?

math
So, if a problem says to use the subtraction property of equality to solve an equation.. and an equation is w + 1 = 14 what am I supposed to do?

math
can someone explain what Subtraction property of equality is? I don't understand it.

chemistry
3.1x1024 atoms of He into moles?

operating system
If /home/jenny/draft and /home/alex/letter are links to the same file and the following sequence of events occurs, what will be the date in the opening of the letter? a. Alex gives the command vim letter. b. Jenny gives the command vim draft. c. Jenny changes the date in the ...