# Luis

Most popular questions and responses by Luis
1. ## 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

2. ## 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

3. ## 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 =

4. ## 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!

5. ## 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?

6. ## 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

7. ## 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?

8. ## 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?

9. ## 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?

10. ## trig

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

11. ## 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?

12. ## 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?

13. ## math

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

14. ## 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.

15. ## 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

16. ## 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

17. ## 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?

18. ## 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

19. ## 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?

20. ## Calculus

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

21. ## 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

22. ## 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

23. ## physics

A beam of protons is moving toward a target in a particle accelerator. This im trying to study for my exam by doing problems, however im stuck with this one. any help is appreciated beam constitutes a current whose value is 0.39A. (a) How many protons

24. ## 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

25. ## 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

26. ## 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

27. ## 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?

28. ## Math

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

29. ## 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

30. ## English

Hello, I am asking for these to be reviewed. I do not want answers; I just want to know if these answers look good. If you would just tell me which ones are wrong and why? Thank you for any help. Eliminate unnecessary shifts in tense, mood, voice, or

31. ## 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?

32. ## physics

A car entering the freeway accelerates from 10.2 m/s with a constant acceleration of 4.4 m/s2. What is the car’s final velocity when it merges onto the highway and reaches its cruising speed 4.2 seconds later? A 28.7 m/s B 11.2 m/s C 18.5 m/s D 8.28 m/s

33. ## 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

34. ## 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

35. ## 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 _____.

36. ## math

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

37. ## 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

38. ## chemistry

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

39. ## 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!)

40. ## 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

41. ## math

express(2/3x-1)^2 as a trinomial?

42. ## math

why did king kong eat a truck?

43. ## Chemistry

You have two gas-filled balloons, one containing He and the other containing H2. The H2 balloon is twice the size of the He balloon. The pressure of gas in the H2 balloon is 1 atm, and that in the He balloon is 2 atm. The H2 balloon is outside in the snow

44. ## 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.

45. ## Calculus

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

46. ## 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

47. ## 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

48. ## algebra

The following equation is used to find c, the total cost for printing a quantity of high school yearbooks, b. c=5b+200

49. ## English

I need to double check my work please. Revise to create pronoun-antecedent agreement and eliminate the generic he and any awkward pronoun reference. 1) While shopping for a new computer for school, I noticed that a laptop costs much less then they use to.

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

51. ## chemistry

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

52. ## physics

if a spinning amusement-park ride has an angular speed of 1.2 rad/s, what is the centripetal acceleration of a person standing 12m from the center of the ride?

53. ## 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)

54. ## AP Biology

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

55. ## physics

A simple pendulum consists of a light string 1.70 m long with a small 0.490 kg mass attached. The pendulum starts out at 45^\circ below the horizontal and is given an initial downward speed of 1.50 m/s. At the bottom of the arc, determine the centripetal

56. ## math

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

57. ## 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

58. ## Physics

A red ball is thrown down with an initial speed of 1 m/s from a height of 27 meters above the ground. Then, 0.6 seconds after the red ball is thrown, a blue ball is thrown upward with an initial speed of 24.5 m/s, from a height of 0.7 meters above the

59. ## Physics

A battery has an internal resistance of 0.42. A number of identical light bulbs, each with a resistance of 31.500, are connected in parallel across the battery terminals. The terminal voltage of the battery is observed to be one-half the emf of the

60. ## English

Can anyone help me check my work please. I need to revise the paragraph to establish a clear antecedent for every pronoun that needs one. Original: In the summer of 2005, the NCAA banned the use of mascots that could be considered offensive to American

61. ## English

Can anyone help me with these. I need to eliminate unnecessary shifts in tense, mood, voice, or person. 1)The greed of the 1980’s gave way to the occupational insecurity of the 1990’s, which in turn gave way to reinforced family ties in the early

62. ## Physics

A simple pendulum consists of a light string 1.70 m long with a small 0.490 kg mass attached. The pendulum starts out at 45^\circ below the horizontal and is given an initial downward speed of 1.50 m/s. At the bottom of the arc, determine the centripetal

63. ## language-poetrypart 1

When a poet wishes to use figurative language he or she will use words that are a)Commotativo and denotativo b) Only denotativo c) Only commotativo d) Ambiguous

64. ## 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

65. ## 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

66. ## Math, Geomertry

A total solar eclipse occurs when the moon passes between the earth and the sun, and the darkest shadow cast by the moon, called the umbra, hits the surface of the earth. If the umbra does not hit the surface, as shown in the following figure, then a total

67. ## Math

My son has a homework (Kindergarden) where he has numbers and next to it there are five square frames. The numbers are 3 and 4. The instructions are as follows: Place counters in the five frames to show the number. Draw counters. Trace the number. What are

68. ## geo

Jackson is creating a water garden surrounded by a triangular patch of grass. If the pond will take up the space indicated by the circle, how many square feet of sod will he need to complete the garden (use 3.14 for and round your answer up to the next

69. ## Physic

Calculate the average speed of an oxygen molecule (with a mass of 5.3e-26 kg) at room temperature (300 Kelvin)show your work

70. ## 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

71. ## Pre calculus

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

72. ## Ochem

By looking at the chemical structures of acetaminophen, aspirin, caffeine, ibuprofen, and naproxin sodium, how are you able to determine the relative polarity of each? Does it have something to do with the symmetry of the structure? Please help!

73. ## physics

A simple pendulum consists of a light string 1.70 m long with a small 0.490 kg mass attached. The pendulum starts out at 45^\circ below the horizontal and is given an initial downward speed of 1.50 m/s. At the bottom of the arc, determine the centripetal

74. ## 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.

75. ## 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

76. ## 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?

77. ## calculus

A 6ft tall woman is walking away from a srteet lamp at 4 ft/sec that is 24ft tall. How fast is the length of her shadow changing?

78. ## math

bystander at the Pegasus Parade, is lying on his back and observing a large balloon of a cartoon character, floating directly above Broadway Street. He is located 32 feet from a point on the street directly beneath the balloon. To see the top of the

79. ## physics

a dog runs down his driveway with an initial velocity of 4.0 m/s. the dog then accelerates at 2.5 m/s^2 for 5.0 s. what is the final velocity of the dog?

80. ## Calculus

An inverted cone has a diameter of 42 in and a height of 15in. If the water flowing out of the container is 35pi in^3/sec , how fast is the depth of the water dropping when the height is 5in?

81. ## Math

Estimate the value of 51 to the nearest whole number

82. ## 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

83. ## Science

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

84. ## 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.

85. ## Math, Geometry

The percent grade of a highway is the amount that the highway raises or falls in a given horizontal distance. For example, a highway with a four percent grade rises 0.04 mile for every 1 mile of horizontal distance. a. How many feet does a highway with a

86. ## 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

87. ## 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

88. ## Physics

Frank is traveling the posted speed limit of 36 mi/hr in a school zone. A deer darts out between two cars. He instantly hits the brakes and the car decelerates at a rate of 5.0 m/s^2. a) how much stopping distance will he require in (meters)? b) If he was

its werid finiding 8x - 13 and 7x + 11 but idk if i should add and equl to 360 its paralleograms and finding x its a triangle please help

90. ## English

Would someone please check my work. I need to combine the following sentences into one by using a semicolon. 1)Abalone fishing in California is strictly regulated. A person is allowed to harvest only twenty-four of these large mollusks per year. A)Abalone

91. ## Physics

If a person runs the 100m dash in 10.0s, calculate that speed in m/s and km/h.

92. ## Math

My son has a homework (Kindergarden) where he has numbers and next to it there are five square frames. The numbers are 3 and 4. The instructions are as follows: Place counters in the five frames to show the number. Draw counters. Trace the number. Please

93. ## 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

94. ## Physic

You must show your work for full credit.) Calculate the average speed of an oxygen molecule (with a mass of 5.3e-26 kg) at room temperature (300 Kelvin):

95. ## pre-calculus

Currently in school we're learning about proving identities and for extra credit I got this problem. cosB= -8/17 in quad II and I have to find sin 7B. I have gotten this far: sin7B= sin(3B+4B) sin3Bcos4B+sin4Bcos3B my problem I can't figure out how to

96. ## Chemistry

When 3.00 g potassium carbonate (K2CO3 ) was mixed with 20.0 mL of hydrochloric acid (HCl, 4.0M) in a calorimeter, the temperature raised 3.0 degrees Celsius. B. Calculate the enthalpy change (H) of the reaction for per mole patassium carbonate. Assume

97. ## Physics

A simple pendulum consists of a light string 1.70 m long with a small 0.490 kg mass attached. The pendulum starts out at 45º below the horizontal and is given an initial downward speed of 1.50 m/s. find: At the bottom of the arc, determine the centripetal

98. ## uh manoa

A basket of neglible wieght hangs from a vertical spring scale of constant force 1500N/m. If you sundally put a 3.0 Kg adobe brick in the basket, find the maximum distance that the spring will stretch. If, instead, you released the brick from 1.0 m above

99. ## math

2.-The longest one-word name of any place in America is Chargoggagoggmanchauggagoggchubunagungamaugg.This name for a lake near webster, Massachusetts, is 45 letters long. It is a Native American name that means "You fish on you side, I'll fish on mine, and