# Posts by Elizabeth

Total # Posts: 1,064

**Chemistry**

I don't know exactly how to start this question: A sample gas contains 2.95 x 10e24 molecules. The sample is 21.0% oxygen. Calculate volume of oxygen in liters assuming oxygen has a density of 1.308 g/L. Please help me how to do this. I have been stuck and still trying to ...

**Chemistry**

Ok. Please. Check. Thank you both so much. Mass of water: 43.0-26.1=16.9 g H2O Moles of water: (16.9 g H2O)(1 mol H2O/18.0 g H2O)= 0.939 mol H2O Moles of cobalt (II) sulfite: CoSO3= 58.9332+32.066+3(15.9994)=138.9974 g/mol (26.1 g CuSO3)(1 mol CuSO4/138.9974 g CuSO3)= 0.188 ...

**Chemistry**

A 43.0 g sample of hydrated cobalt (II) sulfite is heated to drive off the water. The anhydrous cobalt (II) sulfite has a mass of 26.1 g. Calculate the mass of water. Calculate the moles of water. Calculate the moles of cobalt (II) sulfite. Calculate the mole ratio of water to...

**Science**

For periodic waves, frequency has an inverse relationship to the concept of wavelength. Frequency is inversely proportional to wavelength λ (lambda). The frequency f is equal to the phase velocity v of the wave divided by the wavelength λ of the wave. f= v/w In ...

**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 92.5 kg. The mass of the rock is 0.310 kg. Initially the wagon is rolling forward at a speed of 0.550 m/s. ...

**Physics**

John's mass is 92 kg, and Barbara's is 67 kg. He is standing on the x axis at xJ = +7.50 m, while she is standing on the x axis at xB = +2.50 m. They switch positions. How far and in which direction does their center of mass move as a result of the switch? Answer in ...

**Physics**

A girl is skipping stones across a lake. One of the stones accidentally ricochets off a toy boat that is initially at rest in the water (see the drawing below). The 0.094-kg stone strikes the boat at a velocity of 14 m/s, 15° below due east, and ricochets off at a velocity...

**Physics**

By accident, a large plate is dropped and breaks into three pieces. The pieces fly apart parallel to the floor, with v1 = 2.75 m/s and v2 = 1.65 m/s. As the plate falls, its momentum has only a vertical component, and no component parallel to the floor. After the collision, ...

**Physics**

A 0.014 kg bullet is fired straight up at a falling wooden block that has a mass of 4.0 kg. The bullet has a speed of 760 m/s when it strikes the block. The block originally was dropped from rest from the top of a building and had been falling for a time t when the collision ...

**Physics**

The lead female character in the movie Diamonds Are Forever is standing at the edge of an offshore oil rig. As she fires a gun, she is driven back over the edge and into the sea. Suppose the mass of a bullet is 0.015 kg, and its velocity is +726 m/s. Her mass (including the ...

**Physics**

A 42.4-kg boy, riding a 2.29-kg skateboard at a velocity of +5.37 m/s across a level sidewalk, jumps forward to leap over a wall. Just after leaving contact with the board, the boy's velocity relative to the sidewalk is 6.30 m/s, 9.09° above the horizontal. Ignore any ...

**Physics**

In a science fiction novel two enemies, Bonzo and Ender, are fighting in outer space. From stationary positions they push against each other. Bonzo flies off with a velocity of +1.7 m/s, while Ender recoils with a velocity of −2.7 m/s. (b) Determine the ratio mBonzo/...

**Physics**

A volleyball is spiked so that its incoming velocity of +3.6 m/s is changed to an outgoing velocity of -16 m/s. The mass of the volleyball is 0.27 kg. What impulse does the player apply to the ball? Answer will be in kg*m/s

**Physics**

Bicyclists in the Tour de France do enormous amounts of work during a race. For example, the average power per kilogram generated by seven-time-winner Lance Armstrong (m = 75.0 kg) is 6.50 W per kilogram of his body mass. (a) How much work does he do during a 145-km race in ...

**Physics**

The cheetah is one of the fastest-accelerating animals, because it can go from rest to 18.2 m/s (about 41 mi/h) in 2.7 s. If its mass is 114 kg, determine the average power developed by the cheetah during the acceleration phase of its motion. Express your answer in the ...

**Physics**

A semitrailer is coasting downhill along a mountain highway when its brakes fail. The driver pulls onto a runaway-truck ramp that is inclined at an angle of 10.0° above the horizontal. The semitrailer coasts to a stop after traveling 137 m along the ramp. What was the ...

**Physics**

hmm this isnt the write answer, i wonder what went wrong?

**Physics**

The model airplane in figure below is flying at a speed of 21 m/s on a horizontal circle of radius 18 m. The mass of the plane is 0.82 kg. The person holding the guideline pulls it in until the radius becomes 11 m. The plane speeds up, and the tension in the guideline becomes ...

**Calculus HELP PLEASE!!!**

Find all extrema for the function y=x^5-2x^3+3 on the interval [-10...10]

**Calculus HELP PLEASE!!!**

Find all extrema for the function y=x^5-2x^3+3 on the interval [-10...10]

**Word usage**

1-c 2-b 3-a 4-b5-b6-b7-a8-c9-d10-b11-a12-b13-b14-a15-b16-a17-b18-d19-b20-c

**physics...PLZ HELP! =)**

A constant force acts on a moving object. The object makes a fixed magnitude of displacement in some direction. In general, in what direction is the displacement that will result in the object traveling with the least kinetic energy after the displacement occurs? A.The same ...

**physics..help PLZ!!**

An object undergoes a displacement while being acted on by a constant force directed to the north. The work done on this object by the force is positive during the displacement. Which statement is necessarily true about the average velocity of the object during the ...

**calculus**

suppose f(x) is a function such that f(3)=5, f'(3)=0, and f''(3)=3. Is the point (3, 5) a relative maximum, minimum or inflection point?

**Calculus**

A metal cylindrical container with an open top is to hold 1 cubic foot. If there is no waste in construction, find the dimensions which will require the least amount of material.

**english**

2. According to the Pardoner, what is the best way to collect money from people? (1 point) appealing to their sense of piety openly condemning avarice and greed scaring them with prospects of divine punishment

**art 101**

According to the author, a. the interpretation of a work of art is objective. b. a work of art may fall into more than one theme. c. it doesn’t make sense to compare art from different cultures. d. all of these are the case: the interpretation of art is objective; a work ...

**Physics**

A 200 block on a 54 -long string swings in a circle on a horizontal, frictionless table at 90 A) What is the speed of the block? B) What is the tension in the string?

**10th Grade Literary Essay**

What does F. Scott Fitzgerald suggest about the state of the American Dream, the people who pursue it, and the impact of that pursuit through his depiction of Jay Gatsby and the people in Gatsby’s life? Include specific examples, quotations, and supporting details from ...

**math**

i need help in math but i don't get it

**Calculus**

A hot air balloon headed due east at a speed of 20 miles per hour and at a constant altitude of 180 feet passes directly over an intersection. Find an expression for the balloon's distance d (measured in feet) from the intersection t minutes later.

**early childhood literacy**

O and L

**SIG FIGS**

22.0 has 2 significant figures

**english**

The letter is written by Max. I have to identify the simple & complete subject and verb in this sentence. Along with the verb. I am very confused.

**Spanish**

Letters are: a m i a t a m t d r s Need to unscramble to come up with a "member of the family" Thanks!

**math**

y – (–19) = 25 i'm in sixth grade

**physics**

A motor boat heads east across a river at 5.1 m/s. The river flows south at 2.1 m/s. Calculate the resultant speed.

**physics**

A plane flies south at 220 km/h and is blown west by a 90. km/h wind. Calculate the resultant speed.

**physics**

A boat heads directly west across a river at 8.0 m/s while the river flows directly north at 2.0 m/s. Find VR.

**physics**

A 26 N force and a 42 N force act concurrently at point P. The larger force is directed north and the other acts toward the east. Calculate the resultant force acting on point P.

**physics**

A plane is moving east at 100. km/h while the air around it moves at 30. km/h east. Find VR and draw a vector sketch.

**physics**

A westward force of 12 N acting simultaneously with another westward force of 4.0 N. Find FR and show a vector sketch

**math**

with each array write the factor pair. Rember that the # of row in the array are one factor and that the # of columns in the array is the other factor. Continue to build every possible array until you have all the possible factors of the number. 14 is the number, list the factors

**math**

Is the product of 9 and twice m translated 9(2m) or 9(m+m)?

**Math**

Its basically just fractions times each other 1/2 x 1/2 x 1/2 = 1/8 Its 1 eighth probability So 0.125 Or 12.5% Or 1/8

**Literature**

#11 is not correct the answer would be- realism

**Calculus**

Use newtons method and the function f(x)=x^2-a to derive the mechanics rule. Mechanics Rule for approaching sqrt(a), a>0, is Xn+1=1/2(Xn+a/Xn), n=1,2,3,...

**Calculus**

Thanks!

**Calculus**

Find the point on the graph of function that is closest to the point. f(x)=x^2 (2,1/2)

**Epidemiology**

Can anyone answer this question? The prevalence of undetected diabetes in a population to be screen ed is approximately 1.5% and it is assumed that 10,000 persons will be screened. The screening test will measure blood serum glucose content. A value of 180mg% or higher is ...

**Calculus**

Find the critical numbers of y=x(4-x)^1/2. The answer is x=8/3 but I got x=7/2.

**economics**

people are more likely to vote....when?

**sports**

hi the questions are based on the National Governing bodies of sports development we were give a list to chose from and i picked NGB they were some of the questions

**sports**

hi i am having problems with a essay on national governing bodies. can you help me with-- 1. who awards it 2. how do you achieve it. 3. what are strenghts in terms of improving quality of sports development opportunities for participants 4. and weeknessess as in question 3. I ...

**sports**

hello can you help??? swim 21 --- how will it be measured to see if it is -- was it -- will it be a success. thanks

**Physics**

v = Sqrt(v1^2 + v2^2) v = sqrt(98^2 + 100^2) V = 140.01 V = 1.4 * 10^2

**Tangent Line Approximation**

Given that f(−0.5) = 2 fŒ(−0.5) = 4 , using a tangent line approximation you would estimate f(0) to be?

**Science/Physics**

Explain why a rapidly spinning gyroscope, mounted in a frame that allows it to rotate in any direction independently of the frame’s rotation, tends to maintain its axis pointed in the same direction in space. I just am not getting this!

**Chemistry**

Just to add, salicylic acid reacts with methanol to produce methyl salicylate and water.

**Chemistry**

In the presence of an acid catalyst, salicylic acid reacts with methanol to produce oil of wintergreen and water. If water is added to the solution, a precipitate is formed. Identify the precipitate and explain why it is formed. Don't understand...!

**Calculus**

What is the limit of the following equation? Limit as x approaches infinity of ((e^x) - ln(x)) / (x^3)

**Health**

The 2010 Dietary Guidelines for Americans recommends that in managing one’s weight, a person should balance calories with…? A. Healthy eating B. Physical activity C. Educating oneself about health and wellness D. Community involvement c

**Health**

The 2010 Dietary Guidelines for Americans recommends that in managing one’s weight, a person should balance calories with…? A. Healthy eating B. Physical activity C. Educating oneself about health and wellness D. Community involvement c

**physics**

A tennis ball is thrown horizontally at a speed of 10 m/s from the top of a building 78.4 meters high. How long does it take the ball to hit the street?

**Math**

f(x) = 4 ; x = -3, -2, -1, 0, 1, 2, 3 how do i solve this?

**Math**

what is the slope and y intercept of this equation? x+2=0

**Algebra**

give the domain of the function: f(t)= 3t²+5t+2

**honors chemistry**

SWS fan?

**honors chemistry**

The term "halogen" means "salt-former" and compounds containing halogens are called "salts". All halogens have 7 electrons in their outer shells, giving them an oxidation number of -1. The halogens exist, at room temperature, in all three states ...

**honors chemistry**

Their oxidation number of 0 prevents the noble gases from forming compounds readily. All noble gases have the maximum number of electrons possible in their outer shell (2 for Helium, 8 for all others), making them stable.

**math**

Give the slope and y-intercept of the given line. 1.2x-3y=6 2. y=-2x 3. y=3 4. x+2=0 Find the slope of the line that is a) parallel and b) perpendicular to the given line. 1. x=-8 2. y=10

**Homework Help**

A ruling of the FTC requires that every used car must display a(n) ________ spelling out the warranty terms under which the vehicle is offered for sale. A. vehicle identification chart B. agreement C. option chart D. buyer's guide

**math**

after noon would be 4 hours not 7.

**chemistry**

They are actually found in aqueous solutions, though they are not always written down because they form naturally. In reactions in acidic and basic equations, they are written down. The presence of hydrogen ions are actually measured by pH. They are found with hydronium ion = ...

**chemistry**

HCN(aq) + SO4-2(aq) HSO4-(aq) + CN -(aq) a. What is the Bronsted - Lowry acid in this equation? b. What is the Bronsted - Lowry base in this equation? c. What is the conjugate acid in this equation? d. What is the conjugate base in this equation?

**Honors Chemistry**

I need someone to check these questions. I know its a lot of questions. 2NH3 + Ag+ Ag(NH3)2+ a. What is the Lewis acid in this equation? [Ag+] b. What is the Lewis base in this equation? [NH3] Given H2SO4 is sulfuric acid, HNO3 is nitric acid, and H3PO4 is phosphoric acid, ...

**math**

A rectangular prism has 2 ends and 4 sides. Opposite sides have the same area. The surface area is the sum of the areas of all six sides. Find the area of two sides (Length*Height)*2 sides Find the area of adjacent sides (Width*Height)*2 sides Find the area of ends (Length*...

**Chemisrty**

How many grams of lithium metal would be produced if 0.500g of magnesium was added to a solution of lithium chloride?

**Chemisrty**

How many L of carbon dioxide gas will be produced from the decomposition of 5.0g of sodium hydrogen cardonate?

**Calculus**

Breathing is cyclic and a full respiratory cycle from the beginning of inhalation to the end of exhalation takes about 5 seconds. The maximum rate of air flow into the lungs is about 0.5 L/s. This explains, in part, why the function f(t)=(1/2)sin((2pi*t)/5) has often been used...

**calculus**

In a certain city the temperature (in degrees Fahrenheit) t hours after 9 a.m. was approximated by the function T(t) = 50 + 14sin((pi*t)/12). Find the average temperature (in degrees Fahrenheit) during the period from 9 a.m. to 9 p.m. I got (1/12)((12/pi)(50(12)-14cos((pi)))+(...

**sociology**

Explain the concept of socialization and highlight one agent of socialization that can be impactful on your life, stating how and why.

**Chemistry**

Using the solution: NaOH + HCl yields NaCl + H20 What mass of H20 would be produced by combining 10.0 mL of each reagent? Thanks for any help; it's greatly appreciated!

**Child Development**

When both parents believe that men are capable of nurturing infants a. mothers devote time to caregiving b. fathers devote less time to caregiving c. fathers devote more time to caregiving d. the marital relationship tends to suffer, particulary when me spend little time in ...

**Child Development**

thank you

**Child Development**

So then it is Roles maybe This lesson is kicking my butt

**Child Development**

Dean associates certain activies, roles, and traits as being typical for either males or females. His associations conform to cultural stereotypes and encompass many gender-linked responses. This is an example of gender A.Atypicality B.roles C.typing D.identity I think it is A...

**math**

m= y2 - y1/ x2-x1 m being slope

**Chemistry**

Solubility Rules: 1. Salts of group 1 and ammonia are soluble. 2. Acetates and nitrates are soluble. 3. Binary compounds of group 17, except F, are soluble with metals, except Ag, Hg+, and Pb. 4. All sulfates are soluble, except those of Ba, Sr, Pb, Ca, Ag, and Hg+ . 5. Except...

**Algebra2**

If f (x) = x² + 3 and g (x) = 3x - 1 then find the following: 1. (f/g)(x) 2. (f o g)(x) 3. (f o g)(1) 4. (g o f)(x)

**Algebra2**

If f (x) = x² + 3 and g (x) = 3x - 1 then find the following: 1a. (f+g)(x) 1b. (f+g)(3) 1c. (f-g)(x) 1d. (fg)(x) 1e. (fg)(-1)

**Life orientation**

Critically discuss 8 1ays in which the environment problem impact on the within your community or any other community whitin south Africa

**Algebra 2**

how do you find the slope and y intercept of: x= -3

**Spanish**

i need help translating these sentences. only using the verb "estar" 1. My grandfather took my brother to the university. 2. My best friend is my work colleague. 3. It's my boyfriends necktie. 4. My female cat is in the garden. 5. My male cousin and I had a ...

**Chemistry**

What are the rules to determine the solubility of salts?

**Chemistry**

1. How many molecules does 36.0 grams of water represent? Change the following masses to number of particles by: A) dividing by the molar mass to get the number of moles, and then B) multiplying number of moles by Avogadros number

**Chemistry**

Identify which element is being oxidized and which is being reduced Mg (s) + 2H2O (g) = Mg(OH)2 (s) + H2 (g)

**Geometry**

A spherical water tank has a diameter of 10 feet. How much water does it hold when half full ? ( use 3.14 )

**Chemistry**

Predict the characteristic of the solutions of the following salts. 1.CrBr3 2.NH4ClO4 3.NaCl 4.NiSO4 5.GaI3 6.MgC4H4O5 7.K2CO3

**Intermediate Algebra**

12y^4