# luis

Popular questions and responses by luis-
## chemistry

Complete and balance each of the following equations. K2SO4(aq)+BaBr2(aq)→ Would it be K2SO4(aq)+BaBr2(aq)→K2Br2 +SO4Ba? Express your answer as a chemical equation. Enter no reaction if no precipitate is formed. (How can we know if a solid is formed in

*asked on September 30, 2014* -
## Chemisty

How many grams of Cl are in 38.0g of CF2Cl2? I really want to figure out how to do it. I can't seem to understand any of this Chem homework and it's getting me frustrated, please help!

*asked on September 26, 2014* -
## Math

A wall in Marcus's bedroom is 8 1/3 feet high and 16 1/5 feet long. If he paints 1/3 of the wall blue, how many square feet will be blue?

*asked on December 21, 2016* -
## Math

Use similar triangle to solve. A person who is 6 feet tall standing 140 feet from the base of a tree and the tree casts a 150 foot shadow. The person's shadow is 10 feet in length. What is the height of the tree?

*asked on November 17, 2015* -
## Math

There is a spinner with 12 equal areas, numbered 1 through 12. If the spinner is spun one time, what is the probability that the result is a multiple of 4 and a multiple of 6?

*asked on June 10, 2019* -
## trig

How do I find the exact value of sin (pi/24)?

*asked on March 17, 2013* -
## chemistry

How long does it take light to travel each of the following distances 2462 mi, the distance between Los Angeles and New York. How do we calculate how fast light travels?

*asked on October 13, 2014* -
## Physics, Math

A typical volume of a modern hot air balloon is 2500 cubic metres, and a typical maximum temperature of the hot air is 120 degrees Celsius. Given these figures, and an outside air temperature and density of 15 ∘C and 1.225 kg/m3 respectively, compute the

*asked on September 2, 2014* -
## chemisrty

what is the strongest acid here? H2SO3 H2SO4 H2SeO3 H2SeO4 For oxyacids, the acidity increases with increasing number of oxygen atoms; therefore, H2SO3 and H2SeO3 will be weaker than either H2SO4 or H2SeO4. We have a problem determining which is the

*asked on April 30, 2007* -
## chemistry

A 4.78-g sample of aluminum completely reacts with oxygen to form 6.67 g of aluminum oxide Use this data to calculate the mass percent composition of aluminum in aluminum oxide. (Sorry need help with this!)

*asked on September 27, 2014* -
## Calculus

Express the following in Sigma notation 2+8+18+32+50+72

*asked on January 5, 2010* -
## Calculus

The minute hand of a clock is 6in long. Starting from noon, how fast is the area of the sector swept by the minute hand increasing in in^2/min at any instant?

*asked on December 14, 2009* -
## Personal Finance (Math)

Becka borrowed $100 from her cousin at the rate of 6% per year. If the inflation rate was 2% that year, what is her cousin's actual rate of return on the loan? How do you work this out?

*asked on September 27, 2014* -
## math

find the sum and product of the roots of the equation 5x^2+11x-3=0 ?

*asked on January 18, 2011* -
## Fundamental concepts skills

Putting objects together in a group based on a common criterion such as color or shape is called A. the same name. B. classification. C. lookalikes. D. match-ups. my answer is b.

*asked on January 25, 2015* -
## chemistry

Magnesium has three naturally occurring isotopes: Mg-24 with mass 24.3050 amu and a natural abundance of 78.99 %, Mg-25 with mass 24.9858 amu and a natural abundance of 10.00 %, and Mg-26 with mass 25.9826 amu and a natural abundance of 11.01 %. Calculate

*asked on December 14, 2014* -
## physics

An engine moves a motorboat through water at a constant velocity of 22 meters/second. If the force exerted by the motor on the boat is 5.75 × 103 newtons, what is the power of the motor?

*asked on January 11, 2013* -
## Physics

A string is tied to a 4.4 kg block and a 120 g hanging bucket. students add 20 g washers one at a time to the bucket. the students are unaware that the coefficient of static friction for the block on the table is 0.42. What is the maximum force of static

*asked on October 9, 2011* -
## Physics

A baggage handler throws a 16.0 kg suitcase horizontally along the floor of an airplane luggage compartment with an initial speed of 1.10 m/s . The suitcase slides 2.10 m before stopping.

*asked on November 18, 2015* -
## chemistry

onsider the following reaction between sulfur trioxide and water: SO3(g)+H2O(l)→H2SO4(aq) A chemist allows 61.5 g of SO3 and 11.2 g of H2O to react. When the reaction is finished, the chemist collects 59.3 g of H2SO4.

*asked on October 9, 2015* -
## math

A stone is dropped from a cliff 344 feet high. after how many seconds will it be 200 feet above the ground?

*asked on April 11, 2014* -
## Math

An oil-drilling company knows that it costs $25,000 to sink a test well. If oil is hit, the income for the drilling company will be $375,000. If only natural gas is hit, the income will be $165,000. If nothing is hit, there will be no income. If the

*asked on March 13, 2013* -
## Physics

A baseball is thrown at an angle of 25 degrees relative to the ground at a speed of 23.0 m/s. If the ball was caught 42.0 m from the thrower, how long was it in the air? How high was the tallest spot in the ball's path?

*asked on October 26, 2010* -
## Calculus

Express the following in Sigma notation 2+8+18+32+50+72

*asked on January 5, 2010* -
## social studies

The duties of the legislative branch of the United States government most closely resemble those of A. the Roman senate. B. the Roman army. C. Roman consuls. D. Roman tribunes.

*asked on April 23, 2020* -
## world history

can someone please check my answers. 1.)since independence, in most latin american countries. a.elected governments have been overthrown by a millitary coup d'etat. b.elected governments have continued to function peacefully. c.socialist governments have

*asked on February 21, 2020* -
## social studies

which demonstrates how the Anasazi adapt to their hot dry environment? A the Anasazi moved south where more water as available. B the Anasazi hunted bison for food and clothing. C the Anasazi built permanent dwellings in the side of cliffs. D the Anasazi

*asked on October 5, 2018* -
## Series RL circuits

A series RL circuit contains two resistors and two inductors. The resistors are 43 ? and 54 ?. The inductors have inductive reactances of 70 ? and 40 ?. The total impedance is _____.

*asked on March 9, 2018* -
## Math

Estimate the value of 51 to the nearest whole number

*asked on June 13, 2017* -
## Science

The lesion is located in the right thorax just lateral to the mid-saggital plane

*asked on August 24, 2015* -
## math

kate and alan sell stereos. last month kate sold 24 more stereos than alan. together they sold 164. How many stereos did allan sell?

*asked on April 22, 2015* -
## chemistry

Calculate the theoretical yield of alum if 0.200g of Aluminum was reacted with excess KOH and H2SO4? I don't even know how to start it. Please help. Also I wanted to say thank you for the help I've gotten from this website it has helped me a lot. I feel

*asked on October 16, 2014* -
## Math

Show 2/4 of the set. How many counters?

*asked on April 16, 2014* -
## AP Biology

Why are Eukaryotes more difficult to Transform than Prokaryotes? What methods can be used to transform Eukaryotes?

*asked on April 14, 2014* -
## Pre calculus

P=(-2,2) Q=(3,4) S=(2,-8) PS-3PQ Find the component form and magnitude of the vector.

*asked on April 3, 2014* -
## PHysics XXX

An airplane travels 330 m down the runway before taking off. Assuming that it has constant acceleration, if it starts from rest and becomes airborne in 9.00 s, how fast (in m/s) is it moving at takeoff? A 73.3 m/s B 36.7 m/s C 1490 m/s D 660 m/s

*asked on March 25, 2014* -
## math

Mrs. Browns girls scout troop had a carwash to earn some funds. they saved 1/6 of the money. They used 1/2 of the money to go horseback riding. They then had $100 left. How much did they initially make washing cars/

*asked on April 18, 2013* -
## astronomy

big bang theory define

*asked on July 15, 2012* -
## MATH HELP!

solve equation exactly over interval (0, 2ð) sin(x)= 1-2sin^2(x)

*asked on October 25, 2011* -
## physics

Two identical springs (neglect their masses) are used to “play catch” with a small block of mass 200 g (see the figure). Spring A is attached to the floor and compressed 10.0 cm with the mass on the end of it (loosely). Spring A is released from rest

*asked on July 3, 2011* -
## physics

Two identical springs (neglect their masses) are used to “play catch” with a small block of mass 200 g (see the figure). Spring A is attached to the floor and compressed 10.0 cm with the mass on the end of it (loosely). Spring A is released from rest

*asked on July 3, 2011* -
## Physics

A vertical spring with a force constant of 250 N/m is compressed 7.5 cm and a 0.30 kg ball placed on top. The spring is released and the ball flies vertically upward. How high does the ball go? (thanks for helping)

*asked on July 3, 2011* -
## Physics

Water is lifted out of a well 25.0 m deep by a motor rated at 1.50 hp. Assuming efficiency 90%, how many kilograms of water can be lifted in 1 min?

*asked on July 3, 2011* -
## Physics

a thimble is 32.0 cm from a spherical concave mirror. The focal point lenght of the mirror is 11.0 cm. What is the image position?

*asked on May 2, 2010* -
## Calculus

The voltage,V, in an electrical unit is related to the current,I, and the resistance,R, by the equation V=IR. The current is decreasing at -4amps/sec as the resistance increases at 20ohms/sec. How fast is the voltage changing when the voltage is 100 volts

*asked on December 14, 2009* -
## Math

A triangle has an area of 9 square feet. The height is 6 feet. What is the length of the base?

*asked on April 1, 2020* -
## Math

Write and explicit formula for the following sequence. Then generate the first five terms. A1= 625 R=0.2

*asked on March 12, 2020* -
## math

What is f(–5)? A. 15 B. 5 C. –5 D. 0

*asked on February 14, 2020* -
## world history

can someone please check my answers thank you. 1.)lenin founded the comintern as a way to a. spread the revolution b.take over the government c.suppress soviet dissidents d.improve soviet relations with other nations i chose a 2.)isolationists in the

*asked on December 4, 2019* -
## Math

If Goldberg is delivering presents at an altitude of 5,813.6ft, with the same drag and weight of a 2019 Challenger SRT® Hellcat Redeye, how much HP would he need to reach 400 mph? Pro Tips •100% driveline efficiency •P (air density) at 5813.6 ft =

*asked on December 4, 2019* -
## Math

Estimate the sum or difference 2 9/8 - 2 1/7 A. 2 b. 1 c. 0

*asked on November 2, 2019* -
## Math

5(2x-3)-6x=9

*asked on October 3, 2019* -
## mathematics

show step solve the Sturm Liouville problem Y"+hY=0, NB: h means lambda y(0)+y'(0)=0 y(1)+3y'(1)=0 obleck plz explain better again or damon can you help

*asked on February 8, 2019* -
## Math

show step solve the Sturm Liouville problem Y"+hY=0, NB: h means lambda y(0)+y'(0)=0 y(1)+3y'(1)=0

*asked on February 7, 2019* -
## Chemistry

What is the concentration of salt in some optical saline solution if 4.0 miles of sodium chloride, NaCl, are dissolved in a total of 3 liters of solution? A) 98 M B) 81 M C) 2M D) 6M

*asked on June 7, 2018* -
## Chemistry

How many miles of solute are required to make 90 liters of a 9.0 M solution? A).010 mol B)81 mol C) 100mol D) 91 Mol

*asked on June 7, 2018* -
## math

Tanishas mother buys 38 lemons. they know it takes 8 lemons to make 80 ounces of leomonade. Does Tanisha need more lemons? If not, how many extra lemons does she have? if so, how many more lemons does she need? explain how you found your anwser. she needs

*asked on December 30, 2016* -
## math

Tanishas mom and the Lemon question. can some show how they got 7 lemons as the answer. Thank you luis

*asked on December 30, 2016* -
## math

What is the slope of the line that contains the points (4, –4) and (7, –6)?

*asked on September 25, 2016* -
## Chemistry

A solution of acetic acid, 1.0 mol L–1 CH3COOH, contains sodium acetate, NaCH3COO. The percent ionization of the above solution is 0.25%. The Ka for acetic acid is 1.8 x 10–5. Which of the following is the concentration of NaCH3COO in acetic acid? So i

*asked on June 9, 2016* -
## Science

Christina has a glass of water. Michael has a fruit juice drink. Both drinks are at room temperature, and both students add ice to their drink's. Condensation begins to on the outside of Christina's glass before Michael's. How can they state their

*asked on March 30, 2016* -
## Science

Christina has a glass of water. Michael has a fruit juice drink. Both drinks are at room temperature, and both students add ice to their drink's. Condensation begins to on the outside of Christina's glass before Michael's. How can they state their

*asked on March 30, 2016* -
## Math

How many numbers are there in pie?

*asked on March 30, 2016* -
## Chemistry

what mass of NaCl do you need to make a 500mL of a 0.10M solution?

*asked on March 28, 2016* -
## math

a three digit number with 8 ones and 4 tens. The sum of all my digits is 20. What number am i?

*asked on March 6, 2016* -
## algebra

Find the value of y foe the given value of x and z Y=z+x

*asked on February 15, 2016* -
## Math

5x-2y=4 X+2y=8

*asked on February 10, 2016* -
## math

Which correctly renames 2/3 and 1/2 using a common denominator??

*asked on January 20, 2016* -
## physics

A water-skier is being pulled by a tow rope attached to a boat. As the driver pushes the throttle forward, the skier accelerates. A 83.0-kg water-skier has an initial speed of 5.9 m/s. Later, the speed increases to 11.4 m/s. Determine the work done by the

*asked on December 5, 2015* -
## chemistry

Which is the correct expression for Keq when the chemical reaction is as follows: N2 + 3H2 2NH3.

*asked on November 16, 2015* -
## words problems

a car rental offers two plans-plan a $20per day and 12 cents per mile -plan b -$65 per day free unlimited mileage

*asked on October 25, 2015* -
## Physics

A sports car skids to a stop, leaving skid marks 290 m long. If the coefficient of kinetic friction between tires and pavement is 0.80, how fast was the car going before the skid?

*asked on October 4, 2015* -
## math complex number

Solve (-2+i) / (3-2i) and my answer is (-8-i) / 13. Correct?

*asked on September 5, 2015* -
## Geometry

Can I please get some help? by+2/3=c, for y

*asked on August 27, 2015* -
## Algebra

When 2 parents and 3 children visit a theme park the admission cost is $57. The cost is $33 for 1 parent and 2 children. Find the cost for 1 adult and the cost for 1 child?

*asked on July 2, 2015* -
## Stats

A professor believes that all Thursday sections are cursed and will always score lower on tests compared to Monday sections. To tests this he collects samples of test scores from these two sections. For Monday's section, the mean test score was 60, the

*asked on April 15, 2015* -
## Math

My 10th grade teacher gave us geometry homework and this problem has me stumped for sure. This rhombus has three interior angles: (5x-2)°, (8y+2)°, and (3x+22)° . We are supposed to find the value of x and y. I tried to use an equation by assigning the

*asked on March 12, 2015* -
## Statistics

In a nominal data set, what is the preferred measure of central tendency?

*asked on February 24, 2015* -
## math

a bicycle with a diameter of 24 inches is pedaled at a speed of 70 rotations per minute. find the distance the bike will travel in 48 mins

*asked on February 18, 2015* -
## physics

A football is thrown with an initial upward velocity component of 13.5m/s and a horizontal velocity component of 16.5m/s How much time is required for the football to reach the highest point in its trajectory? How high does it get above the ground?How much

*asked on February 18, 2015* -
## Statistics

A population has u=100 and o=20. If you select a single score from this population, on average, how close would it be to the population mean? Explain your answer. I don't understand the question itself. Please help.

*asked on February 17, 2015* -
## Math

The following set of numbers respresents the average weekly scores of 9 preschoolers on a verbal aggression scale. 19.1, 18.9, 33.5, 18.7, 28.1, 31.5, 20.3, 30.1, 17.9 Consider this to be the entire population of scores. What is the standard deviation? I

*asked on February 16, 2015* -
## fundamental skills

When a teacher chooses learning objectives for a child, which question should be asked? A. What should Kelly learn next? B. Where's Kelly in the learning process? C. Do the plan and materials fit my lesson? D. Has Kelly learned what was taught? c.

*asked on February 15, 2015* -
## fundamental concepts

Free play, eating a snack, painting, hearing a story, and so forth are related to which of the following learning concepts? A. Space B. Classification C. Size D. Time a.

*asked on February 15, 2015* -
## fundamental skills

An 18-month-old child putting large beads in a plastic bowl and pouring them out is A. developmentally superior. B. normal and appropriate. C. developmentally inferior. D. abnormal. my answer I think is a.

*asked on February 15, 2015* -
## fundamental skills

What must a teacher provide for an open-ended question to be successful? A. Heuristics B. Background information C. Discrepant events D. Disequilibrium my answer I think is b

*asked on February 15, 2015* -
## physics

A warehouse worker pushes a crate along the floor, as shown in the figure (Figure 1) , by a force of 9.0N that points downward at an angle of 45∘ below the horizontal. Q1 Find the horizontal component of the push Q2 Find the vertical component of the

*asked on February 12, 2015* -
## Math

A classroom of n = 10 children has a mean score of 17.200 on a measure of hyperactivity. One new child is added to the class, and the mean hyperactivity score for the resulting classroom including all the children is 18.000. Find the value of the new

*asked on February 3, 2015* -
## Stats

A classroom of n = 10 children has a mean score of 17.200 on a measure of hyperactivity. One new child is added to the class, and the mean hyperactivity score for the resulting classroom including all the children is 18.000. Find the value of the new

*asked on January 31, 2015* -
## Math

A pill weighs 70 mg. 7/9 of the pill is the active ingredient. How many milligrams are in the part of the pill that is not the active ingredient? So if 7/9 is active that means 2/9 is not active. I did 2 divided by 9 which gives me .22 I then multiplied 70

*asked on January 31, 2015* -
## Managemnet

How to prepare an EFAS table for United Technologies.

*asked on January 28, 2015* -
## Fund. concepts skills

Which of the following activities emphasizes the concept of comparing? A. Dividing pigs and cows into two separate groups B. Dividing farm and wild animals into two separate groups C. Discussing similarities and differences between stuffed and real animals

*asked on January 25, 2015* -
## english - Compare and Contrast

I would appreciate it if someone would be willing to look over my essay real quick. I just would like to know if I made any critical errors. Please do not correct them just point them out so I can fix it. Thank you very much. General instructions from my

*asked on January 19, 2015* -
## chemistry

A 27.00mL sample of an H2SO4 solution of unknown concentration is titrated with a 0.1422M KOH solution. A volume of 40.22mL of KOH was required to reach the equivalence point. What is the concentration of the unknown H2SO4 solution? Any help would be

*asked on December 14, 2014* -
## chemistry

Calculate the freezing point of a water solution at each concentration. 1.40m? What are the steps to calculate this?

*asked on November 19, 2014* -
## chemistry

What is the molarity of ZnCl2(aq) that forms when 18.0g of zinc completely reacts with CuCl2(aq) according to the following reaction? (Assume a final volume of 165mL .) Zn(s)+CuCl2(aq)→ZnCl2(aq)+Cu(s)

*asked on November 19, 2014* -
## chemistry

V1= 38.8 n1= 1.60*10^-3 V2= 49.9 n2= ? How do we solve for n2 using avogadro's law?

*asked on October 31, 2014* -
## chemistry

Imagine that you have an ideal gas in a 8.00L container, and that 2850 molecules of this gas collide with a square-inch area of the container at any given instant. If the volume is increased to 56.0L at constant temperature, how many collisions will occur

*asked on October 30, 2014* -
## Chemistry

Ho w much water would you need to add to 500 mL of a 0.3 M calcium nitrate solution to make the solution 0.1 M? A. 1.0 L B. 0.50 L C. 1.5 L D. 0.25 L E. 3.0 L The answer is A but I cannot figure it out.

*asked on October 17, 2014* -
## math

A Norman window has the shape of a rectangle surmounted by a semicircle. If the perimeter of the window is 16.200 ft. give the area A of the window in square feet when the width is 3.000 ft.

*asked on September 6, 2014*