# Posts by abby

Total # Posts: 1,210

physics
If the speed of light through material Z is 2.5 × 108 m/s, what is this material’s index of refraction? The speed of light in a vacuum is 3 × 108 m/s.

Math
You have a recipe for homemade cookies that makes 5 batches.if the recipe calls for 3 and 1/3 cups of milk, how much milk would you need to make 1 batch?

To determine the atomic mass of an element, you would take a _________ average of the isotopes that make up that element

algebra. help!
A cafeteria has two soda machines. Once machine has the following flavors: Cola, root beer, and lime. The second machine has lemon, orange, cola, and cherry. Which set represents all flavors in the two machines. a. {Cola, root beer, lime} b. {cola} c. {cola, cola, root beer, ...

Math help
A cafeteria has two soda machines. Once machine has the following flavors: Cola, root beer, and lime. The second machine has lemon, orange, cola, and cherry. Which set represents all flavors in the two machines. a. {Cola, root beer, lime} b. {cola} c. {cola, cola, root beer, ...

physics
To push a 16 kg crate up a frictionless incline, angled at 32° to the horizontal, a worker exerts a force of 108.0 N, parallel to the incline. As the crate slides 1.50 m, how much work is done on the crate by the worker's applied force?

Math
(-3.4,0)

Math
There are four brown shoes and 10 black shoes on the floor. your puppy cares away two shoes and puts one shoe in the trashcan and one in the laundry basket. a. What is the probability that there will be a black shoe in the trash and a brown shoe in the laundry basket?

Science, The Nitrogen Cycle

Science, The Nitrogen Cycle
Multiple Choice: 1. Which organisms are capable of converting gaseous nitrogen in the air into a form that other organisms can use? A. Nitrogen-Fixing Bacteria B. Denitrifying Bacteria C. Decomposers D. Producers 2. Which step in the nitrogen cycle is accelerated at the ...

these are just a few of my homework questions, i have 50 more i just need some help with these ones. i would be so happy for any help that you can give me!!!

1)When evolution was first proposed, which of the following was used as evidence to support the idea? (1 point) A)observations of nature*** B)laboratory experiments C)extensive fossil collections D)genetic sequences 2)How did Darwin and Lamarck differ in their thinking about ...

math
Stop cheating and go back through your lessons so you can actually LEARN instead of cheating.

physics
On the Apollo 14 mission to the moon, astronaut Alan Shepard hit a golf ball with a golf club improvised from a tool. The free-fall acceleration on the moon is 1/6 of its value on earth. Suppose he hit the ball with a speed of 33m/s at an angle 28∘ above the horizontal.

Math Check
Hi! Can someone check this and see if they are correct? Thanks! 1.) Which value of x should the expression be further simplified? √(21)x a.) 5 B.) 6 c.) 11 D. 55 My answer: a 2.) 2√43x is show: Which value of x makes the expression equivalent to 14√43? a.) 7 ...

Algebra 1 Check
Hi! Can someone check this and see if they are correct? Thanks! 1.) Which value of x should the expression be further simplified? √(21)x a.) 5 B.) 6 c.) 11 D. 55 My answer: a 2.) 2√43x is show: Which value of x makes the expression equivalent to 14√43? a.) 7 ...

math
Are you sure?

math
my answer is a for number 1. and d for number 2?

math
An art student wants to make a model of the classroom. The length of the classroom is 2.4 times its width. The length of the students model is 42 in. What should the width of the model be? a. 17.5 in b. 20.5 in c. 83.6 in d. 100.8 in Use mental math to determine the solution x...

algebra. help!
so its open?

Pre-Calculus

Pre-Calculus
Hello! I wanted to know if my answers are right or not? Thanks! :) 1.) Segments AB and CD have the following endpoints. Determine whether the segments are parallel, perpendicular or neither. A (3, 0), B (-2, 2), C (-1, 4), D (-3, -1) My answer: Parallel 2.) Segments AB and CD ...

Pre-Calculus
Hello! I wanted to know if my answers are right or not? Thanks! :) 1.) Segments AB and CD have the following endpoints. Determine whether the segments are parallel, perpendicular or neither. A (3, 0), B (-2, 2), C (-1, 4), D (-3, -1) My answer: Parallel 2.) Segments AB and CD ...

Pre-Calculus
Hi! I have three questions that I need checked over just to make sure I understand it. Thanks! :) 1.) What is the slope of the line that passes through (5, 8) and (-2, 6)? My answer: -2/7 2.) If Segment AB || Segment CD and the slope of Segment AB = 1/2, what is the slope of ...

Math
amy is building a house. the basement floor is at -15 feet. the roof of the house is above 25 feet. express the comparison of height as an inequality. explain the meaning of the inequality

algebra
The sum of 16 and twice Gail's score

math
800000

physical chemistry
In an experiment, at a total pressure of 10atm and 400 degree celcius, the equilibrium mixture 2NH3=N2+3H2 the ammonia was found to have dissociated to the extent of 96%. Calculated Kp for the rxn. (reversible rxn).

English
Which principal part of the verb is used in the following sentence? You do good work in history class.

math
In the diagram, the circle will be dilated by a scale factor of 3 about the origin. The points C, A, and B map to C', A', and B' after the dilation. What is the length of ? Use the distance formula to help you decide.

physics
A diver with a mass of 51 kg reaches a maximum height of 5.8 m above the water. When the diver has fallen 2.8 m from the apex, what is her kinetic energy (J)? Assume horizontal velocity is zero.

math
A woman buys a \$ 78 necklace at a jewelry store. She gives the jeweler a check for \$ 100. Because he does not have the \$ 22 change, he goes to another merchant next door. There he exchanges the woman's check for \$ 100 in cash. He returns and Gives the woman the necklace ...

physics
A mass m is gently placed on the end of a freely hanging spring. The mass then falls 21.3 cm before it stops and begins to rise. What is the frequency of the oscillation? I found the same question (with a different length) posted on here, but following the steps of the answer ...

science 1 question!!!
thanks danny i got a 4/4

Calculus
Compute the absolute and relative errors in using c to approximate x. x=e;c=2.68

Physics
A box is pushed down an incline from point A to point B by a force F (and also under the influence of its weight). The distance from A to B, along the ramp, is 5.0 m. The force F is parallel to the incline, as shown, and has a magnitude of 2.0 N. The force of kinetic friction ...

Physics
Two particles with the same mass and same initial speed collide and stick together and leave the collision with half of their initial speed, bound together as one particle. What was the angle between the initial momenta of the particles before the collision?

Physics
Two particles with the same mass and same initial speed collide and stick together and leave the collision with half of their initial speed, bound together as one particle. What was the angle between the initial momenta of the particles before the collision?

Spanish 2
Can someone help me with these two? Thanks! :) Directions: Re-write the sentences in Spanish. The sentences are in all tenses. 1.) Include a direct or indirect object pronoun in the re-write: He used to buy books for the students. 2.) We have eaten breakfast. My answers: 1.)...

social studies
Its not right. My answer is Civilian Violence, and it affects the young people (daily), now political parties do affect the young people, but not (daily)

statistics
A manufacturer ships toasters in cartons of 50. In each carton, they estimate a 2% chance that one of the toasters will need to be sent back for minor repairs. In a batch of 25,000 toasters, what are the chances that fewer than 475 need to be returned? The probability that ...

spanish - HELP!
Thank you!!

chemistry
1. How many different 4p orbitals are there? 2. How many radial nodes are there? 3. How many angular nodes are there? (excluding the radial nodes) I thought it was 2,1, 2??

chemistry
1. it takes: ____ electrons to fill the 6d subshell of an atom. 2. It takes _____ electrons to fill the n=6 shell of an atom. I thought it was 22 and 72?

chemistry
What is the velocity, in meters per second, of a beam of electrons if they are to display a "de Broglie" wavelength of 41.2 um?

chemistry
no, there is no diagram. they just say it: 8p1 is the orbital number. So n=8. but i'm stuck from there. Thank you for your help.

chemistry
What is the longest wavelength of light that can be emitted by a hydrogen atom that has an initial configuration of 8p^1? Thank you!!

chemistry
Thank you!! You are so helpful!

chemistry
What is (delta E) for the traansition of an electron from n=9 to n=4 in a Bohr hydrogen atom? What is the frequency? Thank you!

chemistry
What is the wavelength, in nm, of light with an energy content of (1.35x10^3 kJ/mol)? Thank you!!!

English 9 - HELP!
I wanted you to check my answers. 1. c 2. c 3. a 4. c 5. a 6. d 7. b 8. e

English 9 - HELP!
1. The small boat was scudding into the open sea with a full sail. (1 point) getting stuck sinking deeply moving swiftly rocking harshly 2. As an outdoor enthusiast, Kristina abhorred the fact that people left debris along the hiking trail. (1 point) recently discovered ...

science
i love this homework help program but i am trying to find an answer to this problem and all there is is the question. could you maybe help me out a little bit more by posting the answer too.

chemistry
Given the following thermochemical equations, NO(g) + (1/2) Cl2(g) --> NOCl(g) -37.78 kJ (per mol NOCl) NO(g) + (1/2) O2(g) --> NO2(g) -56.53 kJ (per mol NO2) 2 NO2(g) --> N2O4(g) -58.03 kJ (per mol N2O4) what is the standard enthalpy change for the reaction below? ...

chemistry
What is w when 1.27 kg of H2O(l), initially at 25.0oC, is converted into water vapour at 133oC against a constant external pressure of 1.00 atm? Assume that the vapour behaves ideally and that the density of liquid water is 1.00 g/mL. (Remember to include a "+" or &...

chemistry
A 0.016076-mol sample of an organic compound was burned in oxygen in a bomb calorimeter. The temperature of the calorimeter increased from 23.7oC to 24.5oC. If the heat capacity of the calorimeter is 4.98 kJ (oC)-1, then what is the constant volume heat of combustion of this ...

Science
um.. A d aa is right but this is just NASTY

Math
The area of a rectangle is 32 in.² the length is twice the width. what is the perimeter of the rectangle?

chemistry
A sample of gas is compressed from 13.57 L to 3.93 L using a constant external pressure of 2.91 atm. At the same time, 1,759 J of heat flows into the surroundings. What is the internal energy change for the gas?

chemistry
A 0.016076-mol sample of an organic compound was burned in oxygen in a bomb calorimeter. The temperature of the calorimeter increased from 23.7oC to 24.5oC. If the heat capacity of the calorimeter is 4.98 kJ (oC)-1, then what is the constant volume heat of combustion of this ...

chemistry
How do you calculate the volume on the left and on the right?

chemistry
The enthalpy change for the reaction below at 25oC is -2,051 kJ (per mole of C10H22). What is the internal energy change for the reaction at 25oC? 10 CO(g) + 21 H2(g) --> C10H22(l) + 10 H2O(l) Enter your answer in kJ (per mole of C10H22), rounded to the nearest kilojoule.

chemistry
The standard enthalpy of combustion of C2H6O(l) is -1,367 kJ mol-1 at 298 K. What is the standard enthalpy of formation of C2H6O(l) at 298 K? Give your answer in kJ mol-1, rounded to the nearest kilojoule. Do not include units as part of your answer. Note: The standard ...

chemistry
Given the following thermochemical equations, NO(g) + (1/2) Cl2(g) --> NOCl(g) -37.78 kJ (per mol NOCl) NO(g) + (1/2) O2(g) --> NO2(g) -56.53 kJ (per mol NO2) 2 NO2(g) --> N2O4(g) -58.03 kJ (per mol N2O4) what is the standard enthalpy change for the reaction below? ...

chemistry
When a 6.79-g mixture of methane, CH4, and ethane, C2H6, is burned in oxygen at constant pressure, 369 kJ of heat is liberated. What is the percentage by mass of CH4 in the mixture? The standard enthalpies of combustion for CH4 and C2H6 are -890.3 kJ mol-1 and -1569.7 kJ mol-1...

chemistry
What is w when 1.27 kg of H2O(l), initially at 25.0oC, is converted into water vapour at 133oC against a constant external pressure of 1.00 atm? Assume that the vapour behaves ideally and that the density of liquid water is 1.00 g/mL. (Remember to include a "+" or &...

chemistry
Ah! okay! But thank you so much for answering a few!

chemistry
Hello, a few questions: Thanks so much! 1. The heat capacities of titanium and water are 0.522 J g-1 K-1 and 4.184 J g-1 K-1, respectively. What is the final temperature of the titanium-water mixture if a 175.0-g sample of titanium, initially at 90.0oC, is added to 50.0 g of ...

Math
A line in coordinate plane contains the points P(2, -7) and Q(-4, -1). What point is the midpoint of PQ?

The Power of Media
Ok, #1 is Which of the following is an example of a print medium? a.) a blog b.) a newspaper ******* c.) a magazine’s website d.) all of the above

Is a blog a print media? yes or no?
Oh ok, thanks!

Is a blog a print media? yes or no?
Is a blog a print media? yes or no? I think yes it is.

chemistry
we're in the same class!

chemistry
A 33.0-L cylinder contains 481 g O2(g) at 22.5°C. What mass of O2(g) must be released to reduce the pressure in the cylinder to 6.16 atm, assuming the temperature remains constant? Thanks! :D

chemistry
Hydrogen peroxide, H2O2, is used to disinfect contact lenses. What volume of O2, in mL, or O2(g) at 31 degree celsius, and 741mmHg can be liberated from 10.0mL of an aqueous solution containing 3.00% H2O2 by mass? The density of aqueous solution of H2O2 is 1.01g/mL. Thanks! :)

Math ~ Need Help! ~
• 1. Draw a segment and create a perpendicular bisector using the geometric construction techniques. • 2. Draw an angle and create an angle bisector using geometric construction techniques.

Math! HELP!
Can you help me with some graph ones?

Math! HELP!
Reiny, Steve!! I need help!

Math! HELP!
For questions 14-15, find the simplified form of each expression. (3/2b^4)^3 (3/5y^4)^-2

Language Arts- Writeacher check again
#2. Which is the correct MLA citation for a magazine article? a.) Brian Carson. ''The Real Story Behind Big Foot.'' Myths and Legends Mar. 2010: 20. Print. b.) Carson, Brain. ''The Real Story Behind Big Foot.'' Myths and Legends Mar. 2010: 20. ...

Language Arts-Only 2 answers to check!
I just need #2 and #3!

#1. What is one thing a strong introduction does NOT do? a.) capture the reader's interest b.) present evidence to explain the topic******* c.) provide background information d.) state the main idea of the report #2. Which is the correct MLA citation for a magazine article...

Read the following passage to answer #1 and #2. April 15, Miss Kinnian says I'm learning fast. She read some of the Progress Reports and she looked at me kind of funny. She says I'm a fine person and I'll show them all. I asked her why. She said never mind but I ...

Math
a 16-foot ladder is leaning against a house and is 2 feet away from the foundation of the house. How high up will the ladder reach?

Is the Cations and Anions right?
Is the Cations and Anions right? Iron (III) Sulfate its F 3+ and SO2- Colbalt (II) Chloride its Co+ and Cl-2 Nickel (II) Chloride its Ni 2+ and Cl-2 Copper (II) Sulfate its CU+ and SO-4 Are these right?

History

History
Thank you!

History
China but when I took the test it said that, that was wrong.

History
During the nineteenth century, which of the following countries experienced a decrease in industrial production? A. Britain B. China C. India D. Japan Not sure I think the answer is C.

Art
1. This is where an interior designer does most of her work. in a factory at the client's home in an office <<<<<<<<< in a studio 2. When looking at fabrics, an interior designer will focus on these characteristics. shape and form space and color...

MATH
Lucy was helping her parents construct a concrete birdbath in her backyard. they had a cone shape and a flattened cylinder. how did they put this birdbath together?

science
whats the uses of the element mercury?

Science
Well Seeing as in the Answer is not C, and i believe its not D, And I really Dout' its C because It will not increase health in the future it will decrease it so there answer i would give would probably be B...

Jiskha is totally right i got 100% THANKS SOOOOOOOOOOO MUCH

Mathematics
A man received an invoice for a leaf blower for \$478 dated April 17 with sales terms of 4/10 EOM. How much should he pay if he pays the bill on April 29? is it - 478-(478*4/100)= \$458.88

Mathematics
296 :)

Mathematics
Find the amount of increase if 740 is increased by 40%

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