laura

Most popular questions and responses by laura
1. physics

A space station, in the form of a wheel 110 m in diameter, rotates to provide an "artificial gravity" of 3.00 m/s2 for persons who walk around on the inner wall of the outer rim. Find the rate of rotation of the wheel (in revolutions per minute) that will

asked on July 10, 2010
2. science- physics

A car is traveling at a steady 90 km/h in a 50 km/h zone. A police motorcycle takes off at the instant the car passes it, accelerating at a steady 7.3 m/s/s.How much time elapses before the motorcycle is moving as fast as the car? How far is the motorcycle

asked on September 27, 2015
3. Geometry

line BD bisects angle ABC. Find angle ABD, angle CBD, and angle ABC if angle ABD equals 3x+6 and angle DBC equals 7x-18 please help it would mean a lot

asked on September 10, 2015
4. chemistry

how many "particles in solution" will form from each sucrose (C12H22O11) molecule added to water? Explain. I don't understand where I am supposed to start... What do I need to know to do this problem? thank you

asked on September 12, 2012
5. science- physics

Find the x- and y-components of the vector d⃗ = (6.0 km , 31 ∘ left of +y-axis). I worked it out and got 5.14, 3.09 and apparently it's wrong, I don't know what I did wrong.

asked on October 8, 2015
6. physics

A truck is stopped at a stoplight. When the light turns green, the truck accelerates at 2.5 m/s squared. At the same instant, a car passes the truck going 15 m/s. Where and when does the truck catch up with the car?

asked on September 23, 2011
7. Physics

Calculate the hang time of an athlete who jumps a vertical distance of 0.75 meter.

asked on November 25, 2010
8. Chemistry

At a certain temperature, 0.900 mol of SO3 is placed in a 2.00-L container. 2SO3(g) 2SO2(g)+O2(g) At equilibrium, 0.130 mol of O2 is present. Calculate Kc. Kc= ? Please post the answer if possible or the steps in detail; I have attempted this problem many

asked on March 8, 2013
9. chemistry

Hi, I was hoping someone could double check a chemistry answer for me. I am trying to calculate the Ksp of Ag2CrO4. This question is based on a experiment to determine ksp experimentally. In the experiment the Ksp of silver chromate was calculated using a

asked on May 26, 2013
10. Chemistry

Which of the following pairs would make a good buffer? A. H2C2O4 and HC2O4- B. HNO3 and NO3- C. NaOH and NaCl D. HCl and NaOH Would it be C? I think I remember learning about these in a lesson about buffers, hence why my instinct is to go with C...

asked on September 17, 2016
11. Calculus

Of the infinitely many lines that are tangent to the curve y = −7 sin x and pass through the origin, there is one that has the largest slope. Use Newton's method to find the slope of that line correct to six decimal places.

asked on November 20, 2014
12. Chemistry

If the symbol X represents a central atom, Y represents outer atoms, and Z represents lone pairs on the central atom, the structure Y-:X:-Y could be abbreviated as XY2Z2. Classify these structures according to their shape.

asked on October 19, 2013
13. Physics

A tow truck pulls a car from rest onto a level road. The tow truck exerts a horizontal force of 1500 N on the car. The frictional force on the car is 810 N. Calculate the work done by each of the following forces on the car as the car moves forward 12 m:

asked on May 1, 2017
14. Language A

how does the author of selection 1 express his or her point of view differently than the author of selection two? author of selection one agrees with abandoning federal protection of grizzly bears author of selection one believes that the increase in

asked on May 19, 2016
15. stoichiometry

if 5.00g magnesium is combined with 10.0 g of chlorine, show by calculation which substance is the limiting reactant and calculate the theoretical yield of magnesium chloride for the reaction. Someone PLEASE HELP ME!!!!

asked on September 11, 2009
16. physics

A bus accelerates at 1.4 m/s2 from rest for 10 s. It then travels at constant speed for 26 s, after which it slows to a stop with an acceleration of magnitude 1.4 m/s2. (a) What is the total distance that the bus travels? (b) What was its average velocity?

asked on August 17, 2011
17. math

One day is 86,400 seconds. Express this number in scientific notation and estimate how far the sun's light travels i a day.

asked on December 7, 2011
18. chem

a test tube containing CaCo3 is heated until all the compound decomposes. If the test tube plus calcium carbonate originally weighed 30.08 grams and the loss of mass during the experiment is 4.40 grams, what was the mass of the empty test tube? Write the

asked on April 15, 2007

Determine whether the following are redox reactions. If a redox rxn., identify the oxidized reactant and the reduced reactant. a)N2 + 3H2-->2NH3 : YES, Oxidized=H, Reduced: N b)2H2O2-->2H2O + O2 : YES, Oxidized=H, Reduced: O c)2HBr + Ca(OH)2 -->CaBr2 +

asked on June 1, 2008
20. Chem 110

supposed that a liter of sample water contains 1.00 mmol of Ca2+ ions and 1.50 mmol HCO3- ions. how many millimoles of CaCO3 will precipitate if this water is boiled for 15 mins?

asked on May 9, 2013
21. college math

when eggs in a basket are removed 2,3,4,5,6 at a time there remain, respectively, 1,2,3,4,5 eggs. when they are taken out 7 at a time, none are left over. find the smallest # of eggs that could have been contained in the basket.

asked on April 19, 2009
22. English II

Read the following poem and answer the question that follows. "I Like to See it Lap the Miles" by Emily Dickinson I like to see it lap the miles, And lick the valleys up, And stop to feed itself at tanks; And then, prodigious, step Around a pile of

asked on November 12, 2013
23. Algebra help pls fast

How do you Find the lateral area of a square pyramid. base:8 Height:22. and side:8 Help pls

asked on January 8, 2016
24. math

Sandy measures the length of a hockey stick. she says it it 4 units long. what unit did she use? A. cubes B. inches C. feet D. yards

asked on November 4, 2014
25. Physics

At the low point in its swing, a pendulum bob with a mass of 0.2 kg has a velocity of 4 m/s What is the Kinetic at the low point? and Ignoring air resistance how high will the bob swing above the low point before reversing direction?

asked on February 15, 2013
26. algebra

Chase scored 14 points on Monday, and he doubled his score each day thereafter. How many points did he score on Thursday? A. 224 points B. 112 points C. 56 points D. 42 points Thanks :)

asked on January 24, 2013
27. Math

Alfonso got an 87.5% on his test. He got 21 right. How many questions were on the test??

asked on November 28, 2010
28. Physics

At a constant velocity, a 5kg bag of cement is pulled straight up a 7m wall. How much work is done by the puller? (Gravitational pull is 9.8m/s2, W(J)=F(N)*D(m) How do I work this problem??

asked on May 23, 2015
29. Physics

A moving 3.20 kg block collides with a horizontal spring whose spring constant is 224 N/m. The block compresses the spring a maximum distance of 5.50 cm from its rest position. The coefficient of kinetic friction between the block and the horizontal

asked on January 1, 2014
30. chemistry

If the symbol X represents a central atom, Y represents outer atoms, and Z represents lone pairs on the central atom, the structure Y-:X:-Y could be abbreviated as XY2Z2. Classify these structures according to their shape.

asked on October 19, 2013
31. physics

a simple pendulum consists of a bob of mass 1.8 kg attached to a string of length 2.3 m. the pendulum is held at an angle of 30 from the vertical by a light horizontal string attached to a wall, as shown above. calculate the tension in the horizontal

asked on March 3, 2011
32. Physics

A person climbs from a Paris metro station to the street level by walking up a stalled escalator in 96.5 s. It takes 60.0 s to ride the same distance when standing on the escalator when it is operating normally. How long would it take for him to climb from

asked on September 21, 2012
33. math algebra

the product of two consecutive even numbers is 440. What is the sum of the numbers?

asked on November 30, 2016

A house has increased in value by 38% since it was purchased. If the current value is $483,000 , what was the value when it was purchased? asked on May 4, 2016 35. Principles of Finance HELP!!! Problem 16-7. Pro forma income statement At the end of last year, Roberts Inc. reported the following income statement (in millions of dollars): Sales 3000 Operating costs excluding depreciation 2450 EBITDA 550 Depreciation 250 EBIT 300 Interest 125 EBT asked on September 29, 2006 36. math (log) Express as a single logarithm 2log3 + 4log2 I'm confused as to how to do this, I keep getting the wrong answer. Thank you! asked on January 29, 2018 37. Physics Kenny Klutz drops his physics book off his aunt's high rise balcony. It hits the ground below 1.5s later. a. With what speed does it hit? b. How high is the balcony? (Ignore the air drag) asked on November 25, 2010 38. English II Which of these sentences contains an oxymoron? A. Mr. Keynes was a workaholic who found vacations to be about as relaxing as six rounds wrestling with an alligator. B. Despite his desire to travel during his week off, Mr. Keynes was unable to think of any asked on November 7, 2013 39. math A cereal company finds that the number of people who will buy one of its products in the first month that it is introduced is linearly related to the amount of money it spends on advertising. If it spends$40,000 on advertising then 100,000 boxes of cereal

asked on February 18, 2010
40. Science- Very Urgent

is it reasonable to expect that these models will change again in time? Explain. Like the bohr diagram and etc;

asked on November 14, 2014
41. Chemistry

Combustion analysis of an unknown compound containing only carbon and hydrogen produced 2.277 g of CO2 and 1.161 g of H2O. What is the empirical formula of the compound? How do I go about solving this?

asked on September 19, 2010
42. physics

a device for training astronauts and jet fighter pilots is designed to rotate the trainee in a horizontal circle of radius 10 m. if the force felt by the trainee is 7.75 times her own weight, how fast is she rotating? express in both m/s and rev/s

asked on January 2, 2011
43. Health

1. One of your friends tries to stop an argument between you and your sister. Your friend is practicing A. empathy B. hazing C. harassment D. mediation** 2. Which is the best example of a win-win situation? A. One side gets what it wants. B. Both sides get

asked on January 22, 2016
44. algebra

Find the coordinates of the circumcenter for ∆DEF with coordinates D(1,1) E (7,1) and F(1,5). can you please explain how i can find this answer? i am having trouble

asked on March 14, 2018
45. chem

a.What advantages does ligroin have over n-pentane as a recrystallization solvent? b. What advantages foes ethanol have over n-octanol as a recrystallization solvent?

asked on September 21, 2011
46. college math

Prove: 3/ a(2a^2 + 7)

asked on March 8, 2009
47. math

mike has two mats in the shape of triangles. the scale factor of the two mats is 7/9. what is the ratio of the perimeters?

asked on December 7, 2010
48. algebra with pizzazz

What is it called when a sea bird lands on a channel marker?

asked on December 16, 2008
49. physics

Consider the 671 N weight held by two cables shown below. The left-hand cable had ten- sion T2 and makes an angle of 47 with the ceiling. The right-hand cable had tension T1 and makes an angle of 43 with the ceiling. a) What is the tension in the cable

asked on December 3, 2011
50. Physics

The velocity of the transverse waves produced by an earthquake is 5.08 km/s, while that of the longitudinal waves is 8.3312 km/s. A seismograph records the arrival of the transverse waves 55.9 s after that of the longitudinal waves. How far away was the

asked on May 8, 2011
51. Physics

Commercial airplanes are sometimes towed out of the passenger loading area by a tractor. The 1800 kg tractor exerts a force of 1.75 104 N backward on the pavement, and the system experiences forces resisting motion that total 2400 N. (a) If the

asked on October 8, 2016
52. physics

An electron in an electron beam experiences a downward force of 1.9×10^−14 N while traveling in a magnetic field of 6.4 × 10^−2 T west. The charge on a proton is 1.60×10^−19. a) What is the magnitude of the velocity? b) What is its direction?

asked on April 19, 2011

I did a lab for Organic Chemistry We did a simple distillation of an unknown alcohol to determine the boiling point, which was found to be 74*C The four possibilities for the unknown were methanol, ethanol, 1-propanol and 2-propanol. So from the boiling

asked on October 5, 2010
54. Chemistry

Given the reaction: Cu2+(aq) + S2-(aq) CuS(s) What will happen (a) if CuSO4(aq) is added? And (b) if Na2SO4(aq) is added? A. (a) Nothing; (b) Less product will form B. (a) Less product will form; (b) Nothing C. (a) Nothing; (b) More product will form D.

asked on September 18, 2016

The bases of trapezoid $ABCD$ are $\overline{AB}$ and $\overline{CD}$. Let $M$ be the midpoint of $\overline{AD}$. If the areas of triangles $ABM$ and $CDM$ are 5 and 17, respectively, then find the area of trapezoid $ABCD$.

asked on August 9, 2015
56. World History

Which remained strongly organized and grew more powerful as the Western Roman Empire collapsed? the military command the Christian Church the Orthodox Church the trade networks

asked on November 26, 2013
57. physics

Consider the 671 N weight held by two cables shown below. The left-hand cable had ten- sion T2 and makes an angle of 47 with the ceiling. The right-hand cable had tension T1 and makes an angle of 43 with the ceiling. a) What is the tension in the cable

asked on December 3, 2011
58. AP Statistics

Of all U.S. fourth graders, 71% are assigned mathematics homework three or more times per week. If 5 fouth graders are randomly selected to be checked for this frequency of homework assignment during a randomly chosen week, find the probability that A.)

asked on January 3, 2010
59. physics

A 0.355-kg object undergoing SHM has ax = 2.30 m/s2 when x = 0.235 m. What is the time for one oscillation?

asked on November 16, 2013
60. *Chemistry

Hydrogen reacts w/ sodium to produce solid sodium hydride, NaH. A reaction mixture contains 6.75 g Na and 3.03 g H2. A. Which reactant is limiting? B. What is the theoretical yield of NaH from the above reaction mixture? C. What is the percent yield if 4 g

asked on August 28, 2005
61. math (trigonometry)

A ferris wheel has a diameter of 100m and the bottom of the wheel is 4m above the ground. It rotates two times every 10 minutes. Using this information, complete each question. c) Determine the angular velocity of the Ferris wheel in radians/second d)How

asked on January 27, 2018
62. World Literature

Hi I really need help with the following questions. 1. In"My heart leaps up when I behold"Wordsworth says " the child is the father of the man" This is often interpreted to mean that our childhood experiences influence the adults that we become. Explain

asked on February 20, 2018

If you separate the socks with equal charges 4 x10-9 !@#$%^&il they’re 7 cm apart, what force will each sock exert on the other? asked on March 3, 2014 64. Physics An object is moving with constant velocity -->v Which situation is impossible in such a circumstance? 1. One force acts on the object. 2. Three forces act on the object. 3. No forces act on the object. 4. Two forces act on the object. 5. Four forces act on asked on June 30, 2013 65. physics a roller coaster car moves 200 ft horizontally and then rises 135 ft at an angle of 30 degrees above the horizontal. It then travels 135 ft at an angle of 40 degrees downward. what is its displacement from its starting point? im not really sure what to do, asked on September 2, 2008 66. Chemistry help please! Why does a clear, saturated solution of PbI2 form a yellow precipitate when a small amount of KI is added to the solution? A. KI is insoluble in PbI2. B. PbI2 is always insoluble in water. C. Adding KI is like adding I-, which drives the reaction toward asked on September 19, 2016 67. Analytical Chemistry Match the following terms about analytical precipitations to their definitions: A.) Coprecipitation B.) Adsorption C.) Absorption D.) Gathering E.) Masking F.) Digestion G.) Peptization 1.) Inclusion or occlusion of impurities within a crystal. 2.) Binding asked on February 28, 2014 68. World History What impact did Emperor Constantine's establishment of the “New Rome” (Constantinople) have on the Roman Empire? A.The expense of building the new city impoverished the later Empire. B. The pope moved his headquarters from “Old Rome” to “New asked on November 7, 2013 69. Algebra 1 Math an insect flies 20ft in 1 s. how fast does the insect fly in miles per hour? asked on October 23, 2013 70. School What is the best description of an advanced placement course? A. a rigorous version of a regular subject B. a course that is consistent with college/university courses and prepares a student to take AP exams in a particular subject area and opt out of asked on September 19, 2017 71. math help please?! An object moving vertically is at the given heights at the specified times. Find the position equation s = 12 at^2 + v (small o) t + s (small o) for the object. At t = 1 second, s = 161 feet At t = 2 seconds, s = 98 feet At t = 3 seconds, s = 3 feet a. asked on August 29, 2016 72. physics Two trains face each other on adjacent tracks. They are initially at rest, and their front ends are 50 m apart. The train on the left accelerates rightward at 1.05 m/s2. The train on the right accelerates leftward at 0.93 m/s2. (a) How far does the train asked on August 17, 2011 73. statistics For this problem, assume the balls in the box are numbered 1 through 9, and that an experiment consists of randomly selecting 3 balls one after another without replacement. What probability should be assigned to the event that at least one ball has an odd asked on September 13, 2010 74. Pre-Algebra Help pls fast How do you Find the lateral area of a square pyramid. base:8 Height:22. and side:8 Help pls asked on January 8, 2016 75. Grammar Read the following short excerpt of student writing. Use your vocabulary and grammar knowledge to determine which suggestions you would make to improve his or her grammar and word choice. I really thought she loved me but I discovered her grave betrayal asked on November 7, 2013 76. Chemistry I did a back titration with an unknown carbonate and using the average % carbonate (by mass) which I found to be 27.40% and appropriate calculation decided where the unknown is an alkali metal carbonate or an alkaline earth metal carbonate. I have no idea asked on March 5, 2012 77. chemistry The triprotic acid H3A has ionization constants of Ka1 = 9.9× 10–2, Ka2 = 2.7× 10–8, and Ka3 = 5.9× 10–11. a). Calculate the following values for a 0.0570 M solution of NaH2A H+ ?? [H2A^-/H3A]?? b). Calculate the following values for a 0.0570 M asked on March 28, 2013 78. precal A cell phone company’s profit is modeled by the function p(x) = 10x − x2 − 1, where p is expressed in thousands of dollars and x is the number of phones sold in hundreds. How many phones must the company sell to make a profit of more than$15,000?

asked on April 13, 2012
79. Biology

Hi can someone please help me with this? What are the major advantages and disadvantages of an arthropod's exoskeleton? For the advantages I have provides framework for support, protects soft body tissue and slows water loss in animals that live on land.

asked on January 24, 2018
80. Math

The expression 18h + 100p represents the amount(in dollars) that an insurance salesperson earns for working h hours and selling p policies. How much does the salesperson earn for working 10 hours and selling 3 policies? Thank you so much.

asked on October 8, 2015
81. chemistry

This question I really don't get it. I tried tried tried to figure out how to start solve the problem but still couldn't figure out. So can you help me with one question PLEASE? If so, can you please explain to me how you get the answer? Also can you show

asked on June 14, 2012
82. geometry

TU=1-x,UB=4x+17,TB=-3x

asked on August 27, 2018
83. Math

A recipe uses 3 cups of flour to 1 1/6 cups of milk. if you have 2 cups of flour how much milk should u use

asked on July 7, 2019
84. science- physics

A position vector with magnitude 40 m points to the right and up. Its x-component is 32 m . What is the value of its y-component?

asked on October 8, 2015
85. Civics

Beginning in 1995, most countries in the European Union started to switch to a common currency. The values of different European currencies were linked to the euro. Countries in the European Union could then trade without converting currency. Why would

asked on May 18, 2016
86. stats

In September, the hospital had three coders who coded 1,500 inpatient records, and 22 of the records failed the quality screens. a.   What is the average number of records coded by each coder? b.   What was the average number of records coded each

asked on November 8, 2016
87. Geometry

Two lines intersect so that angle 1 and angle 3 are vertical angles, angle 2 and angle 4 are vertical angles, and angle 1 and angle 2 form a linear pair. how do you slove for x and find the measure of all the angles when angle 2= x sqaured -3x and angle 4=

asked on September 14, 2015
88. chemistry

Phosphoric acid is a triprotic acid with the following pKa values: pKa1=2.148 pKa2=7.198 pKa3=12.375 You wish to prepare 1.000 L of a 0.0200 M phosphate buffer at pH 7.11. To do this, you choose to use mix the two salt forms involved in the second

asked on March 28, 2013
89. Physics

Assuming 95.0% efficiency for the conversion of electrical power by the motor, what current must the 12.0-V batteries of a 845-kg electric car be able to supply to do the following? (a) accelerate from rest to 25.0 m/s in 1.00 min (b) climb a 200-m high

asked on February 14, 2016
90. Finite: College Math

A student wants to buy 3 CDs, but assume that there are 6 CDs featuring the piano, 4 CDs featuring the trumpet, and 7 CDs featuring the saxophone. In how many ways can the selection be made if CD's featuring at least 2 different instruments are selected?

asked on January 20, 2012
91. English (PLEASE I NEED HELP)

Read the following short excerpt of student writing. Use your vocabulary and grammar knowledge to determine which suggestions you would make to improve his or her grammar and word choice. I really thought she loved me but I discovered her grave betrayal

asked on November 7, 2013
92. English II

Read the sentence below and answer the corresponding question. Despite their differences, my father and mother had an __________ divorce. Which word best completes the sentence? adjunct affluent amicable amorous

asked on November 7, 2013
93. Chemistry

Phosphorus pentachloride decomposes according to the chemical equation: PCl5(g) PCl3(g)+Cl2(g) Kc = 1.80 at 250 degrees Celsius A 0.352 mol sample of PCl5(g) is injected into an empty 4.45 L reaction vessel held at 250 °C. Calculate the concentrations of

asked on March 8, 2013
94. account

The net income of Hendley Company for the year is $25,000. Withdrawals during the year were$30,000. No new capital contributions were made during the year. Which of the following statements is TRUE?

asked on May 17, 2019
95. Science

In what ways is Bohr's model of the atom similar to and different from Thomson's model?

asked on November 14, 2014
96. History

How did tea change the life in Europe?

asked on March 6, 2014
97. physicis

a 0.30 kg mass attached to a spring is pulled back horizontally across a table so that the potential energy of the system is increased from zero to 120 J. Ignoring friction what is the kinetic energy of the system after the mass is released and has moved

asked on February 15, 2013
98. Science

In what ways is Bohr's model of the atom similar to and different from Thomson's model? I still need someone to help me.. I don't know the similarities and differences..

asked on November 14, 2014
99. MATH

a borrower received a 30 year ARM mortgage loan for 200,000. Rate caps are 3/2/6 the start rate is 3.50% AND the loan adjusts every 12 months for the life of the mortgage, The index used for this mortgage is LIBOR which for this exercise is 3% at the start

asked on May 19, 2018
100. math

A group of people were asked if they had run a red light in the last year. 433 responded "yes", and 424 responded "no". Find the probability that if a person is chosen at random, they have run a red light in the last year.

asked on November 15, 2016