Monday
November 24, 2014

Posts by SARA


Total # Posts: 3,785

Chemistry
A steel tank at 300 K contains 0.285 L of gas at 1.92 atm pressure. The tank is capable of withstanding a maximum pressure of 5.76 atm. Assuming that doubling the kelvin temperature causes the internal pressure to double, a. at what temperature will the tank burst? b. will it ...
January 16, 2013

Chemistry
I'm supposed to compare the percent composition of gases in the atmosphere at sea level to the percent composition at high altitude.. Would the percents decrease? I don't really understand
January 16, 2013

Chemistry
explain why a sealed bag of potato chips "puffs out" (increases in volume) if taken from sea level to a high mountain pass. I know this has to do with pressure.. so is it because the higher up you go, the less pressure there is? Thanks!
January 16, 2013

bio
The most common protein secondary structures (the alpha helix and beta conformation) are stabilized primarily by A. ionic bonds B. hydrogen bonds C. disulfide bonds D. van der Waals interactions E. hydrophobic interactions
January 16, 2013

integrated math
Suppose a laboratory has a 26 g sample of polonium-210. The half-life of polonium-210 is about 138 days.?
January 15, 2013

Chemistry
Just having some trouble with this chemistry problem.. Thanks for help! Toxic carbon monoxide (CO) gas is produced when fossil fuels such as petroleum burn without enough oxygen. The CO can eventually be converted to CO2 in the atmosphere. Automobile catalytic converters are ...
January 15, 2013

Chemistry
What volume would be occupied at 0°C and 1 atm by 3 mol CO₂(g)? I just might need someone to help me work this out, I would greatly appreciate it! I don't understand this chemistry problem.
January 15, 2013

Physics
i think d
January 15, 2013

math
a ball is dropped from a height of 10 ft. if the ball's height after t sec is modeled by the following equation h(t)=-16t^2+10. when does the ball hit the ground?
January 15, 2013

math
Roses were planted 100 cm apart around a rectangular garden. There were no roses at the corners. They started 1 m from each corner. The garden was 5 m by 3 m. How many roses were planted?
January 15, 2013

Chemistry
Assume that the LHMP is enclosed in a transparent polymer stucture. a. How will the gases inside LHMP be affected by hot days and cool nights? b. What design features might be incorporated in the LHMP to reduce those heating and cooling effects? I know that gases expand in ...
January 13, 2013

Chemistry
In planning to administer a gaseous anesthetic to a patient, a. Why must the anesthesiologist take into account the fact that during surgery the gaseous anesthetic is used both at room (18 degrees C) and the patient's body temperature (37 degrees C)? The warmer the ...
January 13, 2013

Chemistry
If a sample of gas is cooled at a constant pressure until it shrinks to one-fourth its initial volume, what change in its kelvin temperature must have occurred?
January 13, 2013

Algebra
Nadia has 32 coins made up of nickles, dimes, and quarters. The sum of the number of nickels and the number of quarters is three times the number of dimes. If the total value of the coins is $4.60, how many of each kind does she have? I can't figure out how to make this ...
January 13, 2013

Algebra
Nadia has 32 coins made up of nickles, dimes, and quarters. The sum of the number of nickels and the number of quarters is three times the number of dimes. If the total value of the coins is $4.60, how many of each kind does she have? I can't figure out how to make this ...
January 13, 2013

Algebra
Nadia has 32 coins made up of nickles, dimes, and quarters. The sum of the number of nickels and the number of quarters is three times the number of dimes. If the total value of the coins is $4.60, how many of each kind does she have? I can't figure out how to make this ...
January 13, 2013

Algebra
Nadia has 32 coins made up of nickles, dimes, and quarters. The sum of the number of nickels and the number of quarters is three times the number of dimes. If the total value of the coins is $4.60, how many of each kind does she have? I can't figure out how to make this ...
January 13, 2013

Math
Name the lengths of the sides of three rectangles with a perimeter of 12 units. Use only whole numbers
January 9, 2013

Physical science
Compute the gravitational force between two 1.00 kg lead spheres whose centers are 1.00 m apart?
January 6, 2013

physics
Ceres is a dwarf planet located in the asteroid belt between the orbits of mars and Jupiter. the radius of Ceres is 4.76 x 10^5 m. suppose an astronauts stands on the surface of Ceres and drops a 0.85 kg hammer from a height of 1.25 m. the hammer takes 3.0 to reach the ground...
January 5, 2013

Algebra
8s+ 12 = 16, 6s+ 9t = 12 solve by substitution
December 8, 2012

French
1. J'utilise un ventilateur quand il fait chaud. 2. Je n'utilise pas le congélateur si j'ai froid. 3. Il ya une couverture sur mon lit. 4. Mes livres sont sur ​​l'étagère. 5. Je mets mes vêtements dans l'armoire. 6. ...
December 4, 2012

French
1. J'utilise un ventilateur quand il fait chaud. 2. Je n'utilise pas le congélateur si j'ai froid. 3. Il ya une couverture sur mon lit. 4. Mes livres sont sur ​​l'étagère. 5. Je mets mes vêtements dans l'armoire. 6. ...
December 4, 2012

science
Fast help Please Hurry!!!!!!!!!!!!!!!!!!!!!! A bicyclist is in a 50-km race. He says he had an average velocity of 35. What is missing in the cyclist’s velocity? A. units only B. units and distance C. direction only D. units and direction
December 3, 2012

science
Thanks so much!
December 3, 2012

science
im blank today please help thanks!!!!!!!!!!! It takes a car 1.75 h to go from mile marker 10 to mile marker 115. What is the average speed of the car? A. 1.6 mph B. 60 mph C. 65 mph D. 183 mph
December 3, 2012

Algebra2
Check? Give the slope and y-intercept of the given line. 1. 2x-3y=6 = 3y = 2x-6 y = 2/3 x - 2 2. y=-2x = 2/1x + 1 3. y=3 = y=3/1x + 3 3y = 2x-6 y = 2/3 x - 2
November 29, 2012

Algebra2
Check? Give the slope and y-intercept of the given line. 1. 2x-3y=6 = 3y = 2x-6 y = 2/3 x - 2 2. y=-2x = 2/1x + 1 3. y=3 = y=3/1x + 3 3y = 2x-6 y = 2/3 x - 2
November 29, 2012

Algebra2
Graph the given function using the given values of x. 1. f(x) = 5 ; x = -3, -2, -1, 0, 1, 2, 3 2. g(x) = x^3 + 2 ; x = -2, -1, 0, 1, 2
November 29, 2012

math
What's the inequality ? the crowd that heard the President speak was estimated to be 10000 people.The actual crowd could be 750 people more or less than this. what are the possible values for the actual crowd size?
November 27, 2012

Math .-.
All eighth grade students can choose to take one of the following elective courses: art, chorus, band, or woodworking. There are 2o more students enrolled in chorus than art. Band has 3/4 the enrollment as chorus. woodworking has 5 fewer students than band. Which expressions ...
November 26, 2012

Chemistry
Calculate pH of NH4OH which is 1%ionized
November 20, 2012

Grammar
which one should be capitalized? (the Rocky Mountains)
November 19, 2012

7th grade math Ms. Sue please
(1 pt) Max’s percent increase was about 1.1% more than Sara’s.
November 19, 2012

physics
Calculate the net charge on a substance consisting of a combination of 8.9 × 10 13 protons and 2.6×10 13 electrons. The elemental charge is 1.6 × 10 −19 C. Answer in units of C
November 18, 2012

Science
How can knowing about the chemical properties of different elements help a society become more sustainable?
November 14, 2012

Statistics
$50.50+-11.08$
November 14, 2012

chemistry
assuming the reaction goes to completion, determine the final concentration of NH4Cl in the calorimeter. NH4Cl(s)+ H2O(l)-> NH4Cl(aq) concentration of NH4Cl is 1.00M its specific heat is 3.93 and density is g/ml. note: the exact same question was asked for a previous ...
November 13, 2012

physics
A ball is thrown horizontally off the top of a 65 m tall building at a velocity of 7.8 m/s. How far did the ball land from the base of the building? Round your answer to 2 decimal places.
November 11, 2012

physics
A ball is thrown horizontally off the top of a 65 m tall building at a velocity of 7.8 m/s. How far did the ball land from the base of the building? Round your answer to 2 decimal places.
November 11, 2012

physics
A rifle allowed a bullet fired with an initial horizontal velocity to travel 76.0 m while only falling a distance of 0.40 m. What was the initial x-velocity of the bullet? Round your answer to 2 decimal places.
November 11, 2012

Statistics
A random sample of 14 evenings at the O'Sullivan house hold showed that the family received an average of 2.4 solicitation calls each evening. The sample standard deviation was s= 0.9. Find a 99% confidence interval for the population mean number of solicitation calls this...
November 7, 2012

Chemistry
1.63E-27 photon/sec
November 5, 2012

Chemistry
Calculate the mass of CO2 emitted (in lbs) when 1 gallon of octane is burned
November 4, 2012

algebra
If $1000 is invested in an account that earns 11.75%, compounded annually, what will the account balance be after 12 years?
November 4, 2012

physics
its includes 1. about any diameter 2. about a tangent in its plane 3. about a tangent perpendicular to its plane
November 1, 2012

physics
moment of inertia of a ring perpendicular to tangent and its plane
November 1, 2012

Physics
a refree throws a basketball vertically upward with an inital speed of 5.0m/s determine the maxium height above the floor reached by the basketball if it starts from a height of 1.50m
October 28, 2012

Physics
a refree throws a basketball vertically upward with an inital speed of 5.0m/s determine the maxium height above the floor reached by the basketball if it starts from a height of 1.50m
October 28, 2012

Physics
Thanks!!
October 27, 2012

Physics
A car of mass 1100 kg starts from rest at sea level and climbs a hill of altitude 50 m. At the top of the hill the car has a speed of 25 m/s. From the top of the hill the driver turns off the engine and coasts down to an altitude of 15 m. Assume the friction and the air ...
October 27, 2012

Physics
A car of mass 1100 kg starts from rest at sea level and climbs a hill of altitude 50 m. At the top of the hill the car has a speed of 25 m/s. From the top of the hill the driver turns off the engine and coasts down to an altitude of 15 m. Assume the friction and the air ...
October 26, 2012

Physics
A car of mass 1100 kg starts from rest at sea level and climbs a hill of altitude 50 m. At the top of the hill the car has a speed of 25 m/s. From the top of the hill the driver turns off the engine and coasts down to an altitude of 15 m. Assume the friction and the air ...
October 25, 2012

calculus
A street light is mounted at the top of a 6-meter-tall pole. A man 2 m tall walks away from the pole with a speed of 1.4 m/s along a straight path. How fast is the tip of his shadow moving when he is 16 m from the pole?
October 16, 2012

college orgo
calculate how to make 10 mL of 15:85 ethyl acetate:hexane solution from 2 mL of 5:95 ethyl acetate:hexane, using pure hexane and pure ethyl acetate.
October 15, 2012

Physics
Never mind, figured it out.
October 14, 2012

Physics
A wagon is rolling forward on level ground. Friction is negligible. The person sitting in the wagon is holding a rock. The total mass of the wagon, rider, and rock is 97.0 kg. The mass of the rock is 0.320 kg. Initially the wagon is rolling forward at a speed of 0.540 m/s. ...
October 14, 2012

Physics
87 09 7
October 9, 2012

science
I dissolved two different white solids into water. One solid dissolved and gave off heat and the other became cold. Reading various texts online, I was not sure if these were physical or chemical changes. Some texts say if these solids are salts then these are physical changes...
October 8, 2012

physics
A jogger runs down the street at a rate of 1.1 m/s. She sees the finish line, and speeds up to a velocity of 3.6 m/s over 1.1 s. What is the acceleration of the jogger?
October 3, 2012

physics
A ball is dropped from a height of 18.6 m. What is the velocity of the ball the instant it hits the ground?
October 3, 2012

Math does anyone know this?
I have to state whether these equations are parallel or perpendicular y=4x+6 y-4x=-1
October 3, 2012

physics
Sarah shoots a toy dart vertically downward at 11.7 m/s at Mark standing on the ground below. Calculate the dart's velocity after 0.8 seconds.
September 30, 2012

physics
Sarah shoots a toy dart vertically downward at 11.7 m/s at Mark standing on the ground below. Calculate the dart's velocity after 0.8 seconds.
September 30, 2012

bridge to terabitha
Hello i read the book bridge to terabitha and i have an assignment i need some help on. i need to pick 5 characters and describe six events or circumstances that caused the character to change or evolve. i have picked the characters Jesse Oliver Aarons Leslie Burke Mrs. Aarons...
September 30, 2012

math
how do u multiply a positive number and a negitave number
September 26, 2012

science
Draw the condensed structures of the esters formed from the following reactants. Name the compound in each case. (a) butanoic acid and methanol
September 25, 2012

math
There are 5 purple, 3 yellow, and 4 pink rocks in a jar. What is the chance of getting a purple rock if it was pulled out of the jar without looking?
September 25, 2012

chem
Using condensed structural formulas, write a balanced chemical equation for each of the following reactions a)addition of H2O to trans-2-pentene using H2SO4 as a catalyst (two products) i got 2-pentanol adn 3-pentanol but it is counting it wrong!
September 25, 2012

Chemistry
A 2.914 gram sample of gypsum, a hydrated salt of calcium sulfat, CaSO4, is heated at a temperature greater than 170 degrees Celcius in a crucible until a constant mass is reached. The mass of the anhydrous CaSO4 salt is 2.304 grams. Calculate the percent by mass of water in ...
September 24, 2012

math help?
2x+4 (2x+6) I did this and ended up with a decimal number. I distributed then combined like terms.
September 21, 2012

chemistry
The atomic mass of chlorine is listed as 35.454 amu on the periodic table. It has two naturally occurring isotopes, CI-35 and CI-37. What are the approximate percentage of each?
September 20, 2012

PHYSICS
Suppose a moose jumps straight up with an initial upward velocity of 95 m/s. How long until the ungulate lands back on the ground, where it belongs?
September 17, 2012

PHYSICS
If a DeLorean rolls gently (vo = 0) off a vertical cliff, how long does it take it to reach a downward velocity of 78 km/h?
September 17, 2012

physics
Suppose a moose jumps straight up with an initial upward velocity of 95 m/s. How long until the ungulate lands back on the ground, where it belongs?
September 17, 2012

physics
Cubs outfielder Alfonso Soriano catches a ball 5.2 s after throwing it vertically upward. How high did the ball go, relative to his hand?
September 17, 2012

physics
A falling iPad takes 0.16 s to travel past a window 2.1 m tall. From what height above the top of the window did the mobile device fall?
September 17, 2012

physics
If a DeLorean rolls gently (vo = 0) off a vertical cliff, how long does it take it to reach a downward velocity of 78 km/h?
September 17, 2012

physics
A sophomore chemistry student holds a 500mL Erlenmeyer flask full of concentrated nitric acid high above his head at a height of 1.75 meters and declares, "I'm the King of Chemistry!" At that moment another student, startled by the sudden ignition of her Bunsen ...
September 17, 2012

botany
what is the difference between primary walls and secondary walls in plants. (specifically sclerencyma cells- which have secondary and parenchyma and collenchyma - which just have primary walls
September 16, 2012

chem
Draw the three distinct geometric isomers of 2,4-hexadiene. i can draw what it is giving. but i do not get what the geometric isomers are? if you drew it a different way wouldnt that change the name?
September 15, 2012

Algebra..
Help? If f = (1, 2), (2, 3), (3, 4), (4, 5), g = (1, -2), (3, -3), (5, -5), and h = (1, 0), (2, 1), (3, 2), 1. f+g 2. f-g 3. f*g
September 14, 2012

Algebra..
f(x)= x^2+3 ; g(x)=3x-1 Check These Please? 1.(fg)(-1) = 5 2. (f o g)(1) =10 How would you solve this? 1. (g o f)(x)
September 14, 2012

physics
A ping pong ball is rolling across a table at 2.1 cm/s. When the ball is 1.32 m away from the edge your little brother starts to blow on it. If the little doofus hopes to prevent the ball from falling off the edge, what minimum acceleration must be achieved?
September 13, 2012

PHYSICS
A Cessna 350 must reach a speed of 35 m/s for takeoff. If the plane accelerates at a steady 3.8 m/s2, how long must the runway be?
September 13, 2012

PHYSICS
When moving at highway speed, a Triumph America motorcycle is capable of accelerating at 2.1 m/s2. At this rate, how long does it take to accelerate from 103 km/h to 88 km/h?
September 12, 2012

PHYSICS
A ping pong ball is rolling across a table at 2.1 cm/s. When the ball is 1.32 m away from the edge your little brother starts to blow on it. If the little doofus hopes to prevent the ball from falling off the edge, what minimum acceleration must be achieved?
September 12, 2012

chem
Cobalt-60, which undergoes beta decay, has a half-life of 5.26 yr. (a) How many beta particles are emitted in 47.0 s by a 2.39-mg sample of 60Co? i got 2.44e19 but thast wrong
September 12, 2012

physics
When moving at highway speed, a Triumph America motorcycle is capable of accelerating at 2.1 m/s2. At this rate, how long does it take to accelerate from 103 km/h to 88 km/h?
September 12, 2012

physics
The minivan your mom lets you drive accelerates from 12 m/s to 24 m/s in 6.5 s. How far does it travel in this time? Assume constant acceleration.
September 12, 2012

chem please help!
The average energy released in the fission of a single uranium-235 nucleus is about 3. 10-11 J. If the conversion of this energy to electricity in a nuclear power plant is 45% efficient, what mass of uranium-235 undergoes fission in a year in a plant that produces 2000 megawatts
September 11, 2012

Algebra..
Help? If f = (1, 2), (2, 3), (3, 4), (4, 5), g = (1, -2), (3, -3), (5, -5), and h = (1, 0), (2, 1), (3, 2), Find and state the domain. 1. f+g 2. f-g 3.f*g
September 11, 2012

pre algebra
show the work for 136.8 divided by 3600
September 10, 2012

Physics
A baseball batter hits a long fly ball that rises to a height of 49 m. An outfielder on the opposing team can run at 7.7 m/s. What is the farthest the fielder can be from where the ball will land so that it is possible for him to catch the ball?
September 10, 2012

chem
A 73-kg person is accidentally exposed for 215 s to a 16-mCi source of beta radiation coming from a sample of 14C. What is the activity of the radiation source in disintegrations per second? In becquerels? i am not sure if there is an equation for this or wut??
September 10, 2012

chem
do you know how to do it using hte numbers. I know for some problems uneeded information can be added but usually if its more than 2 peices then you use at least one of them
September 10, 2012

chem
it said that answers were wrong im pretty sure i have to use the 73 kg and 215 seconds.. or why would they put that in the question?
September 10, 2012

chem
I am not sure if there is an equation for this problem or wut?? A 73-kg person is accidentally exposed for 215 s to a 16-mCi source of beta radiation coming from a sample of 14C. What is the activity of the radiation source in disintegrations per second? In becquerels? (1 Ci...
September 10, 2012

algebra
art's age is two thirds cal's age, and bob is three years older than art. the sum of their three ages is 45. find the age of each one
September 8, 2012

Physics
A swimmer heads directly across a river, swimming at 1.10 m/s relative to the water. She arrives at a point 60.0 m downstream from the point directly across the river, 80.0 m wide. What is the speed of the river current? What is the swimmer's speed relative to the shore? ...
September 6, 2012

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