Wednesday

November 26, 2014

November 26, 2014

Total # Posts: 727

**Astronomy**

How do astronomers know whether they are seeing planets or stars when they are distant?
*November 24, 2014*

**chemistry physics**

507Hz was the answer according to the textbook so I got it right according to that. Thanks
*November 24, 2014*

**chemistry physics**

Thanks, I used translatorscafe, has most units
*November 24, 2014*

**chemistry physics**

Had to convert 40.0 mi/h to 18m/s and 1090ft/s to 332 m/s So the answer 480*332/(332-18) =507hz Thanks for the link
*November 24, 2014*

**chemistry physics**

A car is traveling toward you at 40.0 mi/h. The car horn produces a sound at a frequency of 480 Hz. What frequency do you hear? Assume that the sound velocity in air is 1090 ft/s. Do I need to convert ft/s to m/s?
*November 24, 2014*

**Chemistry Physics**

What frequency is heard by an observer who hears the 450 Hz siren on a police car traveling at 35 m/s away from her? Assume that the velocity of sound in air is 345 m/s. Is this the correct? 450*345/(345+35) =408Hz
*November 24, 2014*

**math physics**

What frequency is heard by an observer who hears the 450 Hz siren on a police car traveling at 35 m/s away from her? Assume that the velocity of sound in air is 345 m/s. Is this the correct? 450*345/(345+35) =408Hz
*November 24, 2014*

**Math Physics**

would it be (3)(10^8/10^14)
*November 24, 2014*

**Math Physics**

What is the wavelength in metres of an electromagnetic wave with a frequency of 10^14/s?
*November 24, 2014*

**Chemistry Physics**

would this be the setup? 3*10^8/10^14
*November 24, 2014*

**Chemistry Physics**

What is the wavelength in metres of an electromagnetic wave with a frequency of 10^14/s?
*November 24, 2014*

**Chemistry Physics**

What is the wavelength of an electromagnetic wave with frequency 50.0 MHz? Am I starting this problem like this? 3.00*10^8/50*10^6 =6*10^12
*November 24, 2014*

**Math Physics**

thank you
*November 24, 2014*

**Math Physics**

What is the wavelength of an electromagnetic wave with frequency 50.0 MHz? Am I starting this problem like this? 3.00*10^8/50*10^6 =6*10^12
*November 24, 2014*

**Physics**

A plane designed for vertical takeoff has a mass of 6.4 ✕ 103 kg. Find the net work done by all forces on the plane as it accelerates upward at 8.4 m/s2 through a distance of 30.0 m after starting from rest.
*November 20, 2014*

**Physics**

A skier of mass 67.0 kg is pulled up a slope by a motor-driven cable. How much work is required to pull the skier 59 m up a 32° slope (assumed to be frictionless) at a constant speed of 2.0 m/s?
*November 20, 2014*

**math**

i have 50 coins in quarters and nickels. if the total value is $5.90, how many of each coin do i have ?
*November 18, 2014*

**Chemistry Physics**

yes I noticed it, but its still the right setup. thanks
*November 17, 2014*

**Chemistry Physics**

=6072btu thank you for clearing this up, really appreciate all the help.
*November 17, 2014*

**Chemistry Physics**

thanks 144 BTU/lb is the heat fusion of water and ice and the specific heat for ice is 0.51BTU/lb So would I need to set it up Q1 like this? 0.51*33.0*144
*November 17, 2014*

**Chemistry Physics**

I got it all wrong, confusing the tables But for Q1 Q1=0.51*33.0*80cal/kg (not sure how to convert to BTU)
*November 17, 2014*

**Chemistry Physics**

on q2 I mean (72-32)
*November 17, 2014*

**Chemistry Physics**

So,is this the setup to find heat? q1= 33.0 X 3.35X10^5 q2=2.26X10^6*1*(72-42)
*November 17, 2014*

**Chemistry Physics**

How many Btu of heat are required to melt 33.0 lb of ice at 32°F and to raise the temperature of the melted ice to 72°F?
*November 17, 2014*

**math**

2 bananas for 25 cent how many dose 6 cost
*November 13, 2014*

**Physics Science**

How many grams of water at 20°C are necessary to change 800g of water at 90°C to 50°C?
*November 5, 2014*

**Physics**

A 250 g piece of tin at 99°C is dropped in 100 g of water at 10°C. If the final temperature of the mixture is 20°C, what is the specific heat of the tin?
*November 5, 2014*

**Physics - Method Of Mixtures**

Mary mixes 5.00 lb of water at 200°F with 7.00 lb of water at 65.0°F. Find the final temperature of the mixture. -Specific Heat of water is 1.00 BTU/lbs°F
*November 5, 2014*

**Physics Science**

Mary mixes 5.00 lb of water at 200°F with 7.00 lb of water at 65.0°F. Find the final temperature of the mixture. -Specific Heat of water is 1.00 BTU/lbs°F
*November 5, 2014*

**Physics Math**

A flat-bottom river barge is 30.0 ft wide, 85.0 ft long, and 15.0 ft deep. (a) How many ft3 of water will it displace while the top stays 3.00 ft above the water? (b) What load in tons will the barge contain under these conditions if the empty barge weighs 160 tons in dry dock?
*October 30, 2014*

**Math Physics**

Find the water pressure at ground level to supply water to the third floor of a building 8.00 m high with a pressure of 325 kPa at the third level So the given is h=8.00 Ptop=325kPa Density water = 1000 Would I need to set it up like 325+1000*9.81*8.00
*October 28, 2014*

**Fluid Mechanics**

Find the water pressure at ground level to supply water to the third floor of a building 8.00 m high with a pressure of 325 kPa at the third level So the given is h=8.00 Ptop=325kPa Density water = 1000 Would I need to set it up like 325+1000*9.81*8.00
*October 28, 2014*

**Fluid Mechanics**

What must the water pressure be to supply the second floor (18.0 ft/up) with a pressure of 50.0 lb/in² at that level?
*October 27, 2014*

**Fluid Mechanics**

Thanks
*October 27, 2014*

**Fluid Mechanics**

(a) Find the total force on the bottom of a cylindrical gasoline storage tank 15.0 m high with radius 23.0 m. (b) Find the total force on the side of the tank.
*October 27, 2014*

**Physics Science**

(a) Find the total force on the bottom of a cylindrical gasoline storage tank 15.0 m high with radius 23.0 m. (b) Find the total force on the side of the tank.
*October 27, 2014*

**Calculus 1**

Given f(x)= 3e^(1-x^2)*ln(x), find the equation of the tangent line at x = 1.
*October 26, 2014*

**Calculus 1**

A right triangle has a fixed base of length 6 meters and a height that is increasing at a rate of 2 meters/second. At what rate is the length of the hypotenuse increasing when the height is 8 meters?
*October 26, 2014*

**math**

How long will it take a car 3m long travelling at 100km/h to overtake a truck 10m long travelling at 50km/h, if the car is 10m behind the truck
*October 15, 2014*

**College Chemistry lab**

did you manage to solve this?
*October 13, 2014*

**Math @Reiny**

Did I do #2 right? 2.) (1-2i)/2i (1-2i)/2i = (1-2)/i x i/i = (1i-2i)/i^2 = (1i+2) =2+1i
*October 8, 2014*

**Math**

1.) If a = 2 and the vertex of a parabola is (3, -4), will there be a minimum or maximum value for the parabola? What is the value? 2.) If a = 2 and the vertex of a parabola is (3, -4), what is its axis of symmetry?
*October 7, 2014*

**Physics-Intro**

(massbullet * velocitybullet)/massgun (60.0 * 575/4.50) = 7666.66666 Which rounded off becomes 76.7m/s
*October 7, 2014*

**Physics-Intro**

A bullet with mass 60.0 g is fired with an initial velocity of 575 m/s from a gun with mass 4.50 kg. What is the speed of the recoil of the gun?
*October 7, 2014*

**physics**

A car travels along a straight stretch of road. It proceeds for 15.9 mi at 51 mi/h, then 25.3 mi at 41 mi/h, and finally 34.3 mi at 38.6 mi/h. What is the car’s average velocity during the entire trip? Answer in units of mi/h
*October 3, 2014*

**physics**

Find the total force necessary to give a rocket of mass 25,000 slugs an acceleration of 28.0 ft/s2.
*September 30, 2014*

**physics**

One ball is dropped from a cliff. A second ball is thrown down 1.00 s later with an initial speed of 40.0 ft/s. How long after the second ball is thrown will the second ball overtake the first?
*September 30, 2014*

**physics**

A bullet is fired vertically upward from a gun and reaches a height of 7000 ft. Find its initial velocity. How long does it take to reach its maximum height? How long is it in flight?
*September 26, 2014*

**Physics**

A rock is dropped from a bridge to the water below. It takes 2.40 s for the rock to hit the water. Find the speed (in m/s) of the rock as it hits the water. How high (in metres) is the bridge above the water?
*September 26, 2014*

**Math (Pre-Calculus)**

@bobpursley How did you get 3 and 5?
*September 18, 2014*

**Math (Pre-Calculus)**

Can someone help me with this? Thanks! Find the zeros of the function algebraically. f(x)=x^2-8x+15 ---------------- 10x
*September 18, 2014*

**Physics**

When I work this problem I get an answer different from what's given not sure why? A basketball is launched with an initial speed of 8.8 m/s and follows the trajectory shown. The ball enters the basket 0.98 s after it is launched. What are the distances x and y? Note: The ...
*September 14, 2014*

**Calculus**

Using the definition of derivative state the function, f(x) and the value of a for lim as h->0 of (square root of (121+h) -11)/h
*September 7, 2014*

**Math**

Olivia's chessboard is 11 sq centimeters. A chessboard. Has 8 sq on each side. To the nearest tenth what is the width of the chessboard
*September 2, 2014*

**Algebra**

It should be on your formula sheet if not then look it up.
*August 24, 2014*

**Algebra**

Use the distance formula.
*August 24, 2014*

**Algebra 2. Please Help Someone!!**

an airplane's altitude is 100 feet as it descents for a landing on a runway whose touchdown is 5000 ft away. Let the x-axis represent the ground and the y-axis represent the airplane's altitude. What is the slope of the airplane's descent? What is the y-intercept ...
*August 24, 2014*

**maths**

A man uses a fifth of his income on his rent,a third on education and one half of the remainder on clothing. (A) what fraction of his income does he spend on clothing? (B)How much does he spend on clothing,if his income is $2,000,000?
*August 4, 2014*

**Math**

A model airplane is shot up from a platform 1 foot above the ground with an initial upward velocity of 56 feet per second. The height of the airplane above ground after t seconds is given by the equation h=-16t^+56t+1, where h is the height of the airplane in feet and t is the...
*July 24, 2014*

**Math**

Solve the following quadratic-linear system of equations. y=-x^2-x-6 y=2x-2 A. (3, 6) and (–1, 2) B. (4, 6) and (–1, –4) C. (3, –6) and (2, 4) D. (–4, 3)
*July 24, 2014*

**science**

Calculate the volume of a graduated cyclinder that has a radius of 10 mm and a height of 120 mm.
*July 15, 2014*

**math 8th grade**

what the answer to the worksheet how does a hawaiian baritone?
*May 21, 2014*

**Math**

A spinner numbered 1-10 is spun. what is the probability of spinning a multiple of 3 and a multiple of 2?
*May 11, 2014*

**Steps in Chemistry**

add lime. plot sections for water, lime and salt to compare.
*May 8, 2014*

**econ**

What percentage of GDP in 2000 is consumption Calculate net exports for 2001. (Express your answer in billions of dollars.)
*April 7, 2014*

**health**

I got B
*April 2, 2014*

**health**

A was correct for me
*March 29, 2014*

**physics**

a car traveling at 43m/s decelerates at a rate of 7.1 m/s squared. how long did it take the car to stop? what distance did the car travel while stopping?
*March 27, 2014*

**Health**

As mixed-doubles teammates in tennis, Kara and Tran are trying to devise their best strategy against an opponent that has two excellent servers but his physical fitness level is not as good as Kara and Trans. How can Kara and Tran use their superior cardiovascular endurance to...
*February 25, 2014*

**physics**

A spring of force constant 655 N/m is used to launch a 5.25 kg mass from the edge of a frictionless table that is 1.20 m above the floor. How far horizontally away from the table will the mass land if the spring was compressed 42.0 cm before launching?
*February 13, 2014*

**Chemistry**

how many grams of potassium iodide can be produced by the reaction of 150 grams of iodide and 45.6 grams of potassium?
*February 6, 2014*

**physics**

A stream of water strikes a stationary turbine blade horizontally, as the drawing illustrates. The incident water stream has a velocity of + 17.4 m/s, while the exiting water stream has a velocity of – 15.0 m/s. The mass of water per second that strikes the blade is 33.6 ...
*January 30, 2014*

**physics**

A stream of water strikes a stationary turbine blade horizontally, as the drawing illustrates. The incident water stream has a velocity of + 17.4 m/s, while the exiting water stream has a velocity of – 15.0 m/s. The mass of water per second that strikes the blade is 33.6 ...
*January 30, 2014*

**physics**

A stream of water strikes a stationary turbine blade horizontally, as the drawing illustrates. The incident water stream has a velocity of + 17.4 m/s, while the exiting water stream has a velocity of – 15.0 m/s. The mass of water per second that strikes the blade is 33.6 ...
*January 30, 2014*

**physics**

A stream of water strikes a stationary turbine blade horizontally, as the drawing illustrates. The incident water stream has a velocity of + 17.4 m/s, while the exiting water stream has a velocity of – 15.0 m/s. The mass of water per second that strikes the blade is 33.6 ...
*January 30, 2014*

**Health**

The coach noticed that Caleb really started to kick the soccer ball with great amount of power after the kicking drills. Caleb adjusted the power of his soccer kick by increasing the speed of his kicking leg prior to and upon contact with the ball starting his kick from a two ...
*January 30, 2014*

**Physics**

A baggage carousel at an airport is rotating with an angular speed of 0.397 rad/s when the baggage begins to be loaded onto it. The moment of inertia of the carousel is 2440 kg·m2. Ten pieces of baggage with an average mass of 16.5 kg each are dropped vertically onto ...
*January 27, 2014*

**science**

if 4 cars were going 100m the entire time what happens to speed,velocity and accelerationas one car completes one full lap
*January 23, 2014*

**science**

What is the acceleration of a 7kg rocjet if a force of 68.6 kg m/s/s (N) is used to move it away from the earth
*January 21, 2014*

**science**

NOT RIGHT!!! 2 is C
*January 21, 2014*

**American History **

What three rivers did Lewis and Clark use to get to the Pacific Coast?
*January 13, 2014*

**Atomic Model/Science**

I dislike Chemistry :O Anyway I do know this: For an atom, the number of natural occurring protons should have the same number of electrons. So your atom should have 92 electrons given if it's not an (ion or man made isotope).
*January 11, 2014*

**Science**

Let: Star = Sun Planets = Earth It's much simpler to understand the question with what we know. Now to answer your question: The gravity of the Sun keeps the earth in it's orbit. This is also true as the Moon orbits the Earth because of the pull of Earth's gravity...
*January 11, 2014*

**Honor's English**

Thank you :-).
*January 11, 2014*

**Honor's English**

Which of the following describes the underlined phrase in the sentence below? The local softball team won the championship (against all odds). A) prepositional B) participial C) gerund D) infinitive Process of elimination: It cannot be C since a gerund needs to have -ing at ...
*January 11, 2014*

**HEALTH**

I got B. 6
*January 10, 2014*

**alegbra **

Suppose that an insurance agent offers you a policy that will provide you with a yearly income of $50,000 in 30 years. What is the comparable salary today, assuming an inflation rate of 3% compounded annually? My answer is $20,559.34, however, the module says its incorrect.
*December 11, 2013*

**Math**

Sam starts from point A at 8:00am and hikes up a mountain path. He arrives at the top, (point B) at 4:00pm. He camps there for the night and the following morning he starts his descent at 9:00am. He travels faster since he goes downhill and arrives at the bottom (point A) at 3...
*December 2, 2013*

**Math**

If the measurement from the outer edge of the first board to the outer edge of the last board is 144 inches, then there would be 14 spaces between the boards, each measuring 3/8 inch. (14x3/8)+(15x9 1/4)= 144. Now if this section is in the middle of the boardwalk, there would ...
*December 2, 2013*

**math**

(15x1000)/60=250
*December 2, 2013*

**science**

For BOD5 test 1) Why water samples needed dilution? 2)How to check the test accuracy? 3)Under what conditions, the water sample needs "seed"? anyone can help?please.
*December 1, 2013*

**science**

How to eliminate chloride interference up to the COD test?
*December 1, 2013*

**Statistics**

I have two coins: a quarter and a nickel. The quarter has a bias of 1/4 for heads, and the nickel has a bias of 2/3 for heads. I flip each coin 10 times. What is the probability that I observe exactly five heads total? Some explanation of the solution would be appreciated.
*November 29, 2013*

**Physics**

i caught you
*November 28, 2013*

**algebra**

Suppose that an insurance agent offers you a policy that will provide you with a yearly income of $50,000 in 30 years. What is the comparable salary today, assuming an inflation rate of 3% compounded annually?
*November 16, 2013*

**High School Geometry**

I am have a hard time understanding how A and B can be No, but C can be Yes on this problem i.imgur (dot)com/rpJQDf3.png I thought that since AD is not perpendicular to the plane m then no lines shooting off of D onto the plane could be perpendicular.
*November 13, 2013*

**math**

Oh thanks Ms.Sue! :)
*November 7, 2013*

**math**

If a car traveled 168 miles in 3.5 hours, what was the average rate of speed?
*November 7, 2013*

**math**

Thanks Ms.Sue.... you're awesome!
*November 7, 2013*

**Physics**

A 3.00-g bullet (c = 0.0305 cal/g . C° = 128 J / kg . C°) moving at 180 m/s enters a bag of sand and stops. By what amount does the temperature of the bullet change if 80% its KE becomes thermal energy that is transferred to the bullet? Thank ´s fir your help!
*November 3, 2013*

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