# Grace

Most popular questions and responses by Grace-
## Statistics

Suppose a basketball player is an excellent free throw shooter and makes 90% of his free throws (i.e., he has a 90% chance of making a single free throw). Assume that free throw shots are independent of one another. Suppose this player gets to shoot three

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

1.If an animal is an ectotherm, It has? A. A skeleton on the outside of its body B. A skeleton on the inside of its body C. A body that regulates its own internal temperature D. A body that does not produce much internal heat

*asked on December 31, 2017* -
## Chemistry

FeSCN2+ -> Fe3+ + SCN- Solution is initially dark red. If some Ag+ is added to form AgSCN. what happens to position of equilibrium? what happens ot the color?

*asked on February 8, 2011* -
## Trigonometry

How do I find all solutions to: tanx+3cotx=4? The answer choices are: a.) x=arctan3+nPi b.) x=arccot3+nPi

*asked on January 1, 2010* -
## Chem

Write the formulas of the compounds formed by Pb4+ with the following anions: CN−, ClO3−, SO42−, H2PO4−.

*asked on March 4, 2016* -
## Physics

Two cars travel westward along a straight highway, one at a constant velocity of 85 km/hr, and the other at a constant velocity of 115 km/hr. a) Sketch the velocity vs. time graph for both cars and paste your sketch in the space below. b) Assuming both

*asked on October 24, 2010* -
## math

Given: ∆PQR, m∠R = 90° m∠PQR = 75° M ∈ PR , MP = 18 m∠MQR = 60° Find: RQ

*asked on March 14, 2017* -
## Chemistry

Write a balanced chemical equation that represents the self-ionization of water. (Use the lowest possible coefficients. Include states-of-matter at 1 atm and 25°C in your answer.)

*asked on April 2, 2014* -
## Statistics

A national caterer determined that 87% of the people who sampled their food said that it was delicious. A random sample of 144 people is obtained from a population of 5000. The 144 people are asked to sample the caterer's food. If sample proportion, P^, is

*asked on March 22, 2013* -
## Language Arts

What does the aunt in The Story Teller find improper about the bachelor's story? A. It makes fun of Bertha's goodness B. It has too many fantasy elements C. It unrealistically suggests that virtue is always rewarded D. The bachelor tells it without

*asked on September 29, 2015* -
## Math

You flip a coin 30 times and get heads 11 times, so the chance of getting heads is 11\30. Is this an example of theoretical or experimental probability? A. Theoretical B. Experimental Is the answer B? Thank you

*asked on April 9, 2015* -
## Chemistry

An AM station broadcasts rock music at "950 on your radio dial" Units for AM frequencies are given in kilhertz(kHz). Find the wavelength of the station's radio waves in meters, nanometers, and angstroms.

*asked on September 7, 2011* -
## Science please check my answer

Which of the following fossil types is best described as forming when minerals replace all or part of an organism's body? A) A mold B) A petrified fossil*** C) A cast D) A trace fossil

*asked on September 29, 2015* -
## Physics

You're driving parallel to train tracks at 40.0 km/h when a train passes you, going a steady 105 km/h. A track crossing is up ahead, so you begin to speed up at 6.50 m/s2. How far do you drive before you pass the train?

*asked on October 2, 2016* -
## world history

What was a major cause for the Third Italian War of Independence? the border disputes with France and later with Prussia the simultaneous attack of Austria by Prussia and Italy in 1866 the desire to create a vast Italian empire in central Europe C?

*asked on February 11, 2019* -
## history

Which options describe Chinese developments in mathematics? (Select all that apply.) A- The first Chinese book about mathematics, Nine Chapters on the Mathematical Art, was composed before 200 BC. B- The Chinese discovered the ratio of a circle’s

*asked on November 16, 2018* -
## chemistry

a 2.52-g sample of a compound containing only carbon, hydrogen, nitrogen, oxygen, and sulfur was burned in excess O to yield 4.23 g of CO2 and 1.01 g of H2O as the only carbon and hydrogen containing products respectively. Another sample of the same

*asked on February 15, 2014* -
## Operations Management

Consider the following system: -> 0.73 -> 0.73 -> Determine the probability that the system will operate under each of these conditions: (Round your final answers to 4 decimal places, not your intermediate calculations.) a.) The system as shown b.) Each

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

What is the Wavelength( in nm) of the least energetic spectral line in the infrared series of the H atom? I don't understand how to find the least energetic spectral line?

*asked on September 10, 2011* -
## history

Which best describes how Sparta’s culture influenced the city-state’s government? A- Sparta was a society based on exploration and expansion, and its government was also based on this concept. B- Sparta was a society based on being prepared for war,

*asked on November 16, 2018* -
## Help! Communication

HELP!!! effective verbal message formation is about being. 1) Supportive of others 2) Critical of the motives of others 3) informed about a decision process 4) intentional in one's learning. I think the answer is 2 but i'm not sure.

*asked on October 14, 2017* -
## history

explain the relationship of Spindletop's location in Texas to it's importance on the economic development of Texas and the United States.

*asked on October 5, 2016* -
## Biochemistry

Calculate the ph of a 1L solution to wgich has been added 25ml of 10mM acetic acid and 25ml of 30mM sodium acetate

*asked on July 23, 2017* -
## Physics

A 45 kg crate is placed on an inclined ramp. When the angle the ramp makes with the horizontal is increased to 29 degrees, the crate begins to slide downward. What is the coefficient of static friction between the crate and the ramp? At what angle does the

*asked on February 22, 2010* -
## Math #rd grade

Bryan has 3 nickels, 3 dimes, and 2 quarters. What fraction of the coins is either a dime or a quarter? There is a space for only 1 fraction answer.

*asked on January 14, 2014* -
## Physics

A man uses a lever jack to lift a 2.00 × 10^3 kg car to change a tire. Each stroke of the jack lifts the car a distance of 5.00 × 10^(-3) m. The vertical displacement of the handle is 0.75 m for each stroke. How much total force does he use with each

*asked on January 28, 2016* -
## History

What was the importance of the inclusion of the bill of rights in the constitution? a.It limited the power and controls the government b.It guaranteed the protection of basic rights c.it improve U.S relations with the british monarchy d.it proposed a

*asked on September 15, 2017* -
## math

Water is being poured into a conical cup that is 12cm tall. a) When the water in the cup is 9cm deep, what percentage of the cup is filled? b) When the cup is 75 percent filled, how deep is the water?

*asked on April 9, 2017* -
## Language Arts

What does the word conviction mean in this sentence? His voice rang with great conviction as he told us his ideas. A)Anger B)Certainty C)Confusion D)Sorrow

*asked on September 25, 2015* -
## Chemistry

In 1901, Thomas Edison invented the nickel-iron battery. The follwing reaction takes place in the battery. Fe(s) + 2 NiO(OH)(s) + 2 H2O(l) Fe(OH)2(s) + 2 Ni(OH)2(aq) How many mole of Fe(OH)2, is produced when 3.70 mol Fe and 6.95 mol NiO(OH) react?

*asked on February 24, 2014* -
## math

Without using a calculator, choose (a) the larger of cos 40 and cos 50; (b) the larger of sin 40 and sin 50. Be prepared to explain your reasoning.

*asked on February 8, 2017* -
## Math

Suppose you write the letters M-I-S-S-I-S-S-I-P-P-I on cards and mix them in a hat. You choose one card from the hat without looking. What is the probability of picking an S? A.4\11 B.2\11 C.4\7 D.7\4 Is the answer A? Thank you

*asked on April 9, 2015* -
## Math

You roll a pair of number cubes and then flip a coin. Is this an example of independent or dependent events? A. Independent B. Dependent Is the answer A? Thank you

*asked on April 9, 2015* -
## Physics

A cardboard box of unknown mass is sliding upon a mythical frictionless surface. The box has a velocity of 4.56 m/s when it encounters a bit of friction. After sliding 0.700m, the box has a velocity of 3.33 m/s. What is the coefficient of friction of the

*asked on December 15, 2016* -
## social studies

1. Many agree that Native Americans migrated from Asia as early as _______ years ago. (1 point) 2,000 5,000* 30,000 100,000 2. What country controlled the majority of the Americas in 1783? (1 point) Great Britain* France Spain Native American 3. The Treaty

*asked on February 16, 2016* -
## chemistry

1.How many atoms are in a sample of copper with a mass of 18.46 grams? 2.How many formula units are in a sample of salt with a mass of 67.69 grams? 3.How many molecules are in a sample of water with a mass of 44.99 grams? 4.What is the mass in grams of

*asked on February 6, 2011* -
## Geography

Which scenario accurately depicts a way that maps are used as a reference tool? A. A shopper consults a map to discern the best route to a new store. B. A teacher displays a map to point out the name of a local mountain. C. A student consults a map to

*asked on August 30, 2019* -
## Computer Science

The compare_and_swap() instruction (CAS) can be used to design lock-free data structures such as stacks, queues, and lists. The program example shown below presents a possible solution to a lock-free stack using CAS instructions, where the stack is

*asked on March 20, 2019* -
## chemistry

8.What is the mass of 4.56 moles of sulfur dioxide? 9.What is the mass of 4.56 molecules of sulfur dioxide? 10.How many formula units are in 0.456 grams of Ca3(PO4)2? 11.How many moles are in 1.5 x 10 ^23 atoms of fluorine? 12.What is the mass of 2.80 x 10

*asked on February 6, 2011* -
## Geometry

The coordinates of the vertices of △ABC are A(1,4), B(-2,-1), and C(-3,-2). The height h to side BC is √2, and b is the length of BC. What is the area of △ABC? I don't really know how to approach or start this problem, so if you can help, please do!

*asked on September 30, 2019* -
## riddle

Its new and old at the same time

*asked on January 17, 2017* -
## Math

Suppose you write the letters M-I-S-S-I-S-S-I-P-P-I on cards and mix them in a hat. You choose one card from the hat without looking. What is the probability of picking a P? A.4\11 B.2\11 C.4\7 D.7\4 Is the answer B? Thank you

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

how is finding a fractional part of a set different than finding a fractional part of a whole?

*asked on January 7, 2015* -
## maths

The mass of a particular substance is known to grow exponentially at a rate of 0.5% per hour. Its initial mass was 25 grams and, after t hours, it weighed 31 grams. The equation modelling this growth is 25×1.005 t = 31. Use the method of

*asked on May 8, 2011* -
## Physics

A 2260kg truck drives East with a constant velocity of 18m/s. It comes to a stop after traveling 123m. What is the noraml force exerted by the road on the truck? Also, is the distance travelled essential to solve the problem or is unnecessary information?

*asked on October 17, 2016* -
## math

Sasha has 8 red apples. She has 3 fewer green apples than red apples. How many apples does she have? 13 apples 8-3=5 green 8+5=13

*asked on January 25, 2017* -
## Chemistry

Covalent bonds in a molecule absorb radiation in the IR region and vibrate at characteristic frequencies. a) The C---O bond absorbs radiation of wavelength 9.6um. What frequency (in s-1) corresponds to that wavelength? b) The H---Cl bond has a frequency of

*asked on September 8, 2011* -
## CHEMISTRY

The specific heat capacity (cp) of lead is 0.13 J/g °C. How much heat (in J) is required to raise the temperature of 15 grams of lead from 22 °C to 37 °C? a. 2.0 b. -0.13 c. 0.13 d. 29

*asked on May 9, 2010* -
## Science

What has the study of fossils allowed scientists to do? A) Describe the past environments and the history of life. B) Study present ocean temperatures at different depths C) Analyze the chemical compositions of sedimentary rocks and minerals. *** D)

*asked on September 29, 2015* -
## Chemistry

Possible Sources of error in a reaction or sodium bicarbonate and acetic acid. Also known as baking soda and vinegar.

*asked on February 25, 2014* -
## Math

A lighthouse is east of a Coast Guard patrol boat. The Coast Guard station is 20 km north of the lighthouse. The radar officer aboard the boat measures the angle between the lighthouse and the station to be 23°. How far is the boat from the station?

*asked on May 8, 2013* -
## math

third degree with zeros of 2-i,2+i and 2 and a leading coefficient of 4. Construct a polynomial function with stated properties

*asked on October 28, 2017* -
## chemistry

when aqueous solutions of copper II nitrate and sodium phosphate are mixed, sodium nitrate and copper II phosphate are formed. In the balanced chemical equation what is the coefficient of sodium nitrate?

*asked on May 6, 2010* -
## physics

Two large horizontal metal plates are separated by 4mm. The lower plate is at a potential of (-)6v.What potential should be applied to the upper plate to create field strength of 4000v/m upwards in the space between the

*asked on August 28, 2013* -
## math

A certain store is selling an $80 radio $64. If a different radio had a list price of $200 and was discounted at 1.5 times the percent discount on the $80 model, what would its selling price be? a) $90 b) $105 c) $120 d) $140 e) $160

*asked on August 2, 2012* -
## Physics

An engineer is designing a runway for an airport. Several planes will use the runway and the engineer must design it so that it is long enough for the largest planes to become airborne before the runway ends. The largest plane accelerates at 3.30 m/s2 and

*asked on October 23, 2010* -
## Chemistry

How do I do the empirical formula for 37.01% carbon, 2.22% hydrogen, 18.50% nitrogen, and 42.27% oxygen? My teacher gave me the answer (C7H5N3O6), but I can never get that answer.

*asked on December 5, 2014* -
## Physics

A person runs off a 10.0-meter high balcony in a horizontal direction at 5.0 m/s. The swimming pool is at ground level 5.5 meters away from the edge of the balcony. Will the person reach the pool? Assume no air resistance. *I'm having trouble with this

*asked on April 5, 2017* -
## Physics

Hi, the following is a problem that concerns angular momentum: Modern hard drives spin very fast! The part that holds the data is a disk called the platter. Assume an aluminum platter that is 3.5in. in diameter, 1mm thick, and spinning at 5400 rpm. Treat

*asked on February 17, 2017* -
## science

which of the following does not change when a car keeps a constant speed but changes direction

*asked on April 28, 2016* -
## algebra

The ordered pairs (1, 81), (2, 100), (3, 121), (4, 144), and (5, 169) represent a function. What is a rule that represents this function?

*asked on April 10, 2017* -
## MATH

A food snack manufacturer samples 15 bags of pretzels off the assembly line and weighed their contents.If the sample mean is 10.0 and the sample standard deviation is 0.15, find the 95% confidence interval of the true mean.

*asked on April 16, 2015* -
## Math

You have made 3 out of 10 of your last free throws. How many free throws can you expect to make if you shoot 100 free throws? A.30 B.50 C.60 D.75 Is the answer A? Thank you

*asked on April 9, 2015* -
## physics

If the grating is not properly aligned, what are the consequences on the average angular displacement and wvelength reading? Please elaborate. How do grating constants affect the observed spectral lines?

*asked on January 18, 2009* -
## Math - for Reiny

Mandy finds she can get a discount on corn cobs if she buys in bulk. She can get 100 kilograms of corn cobs for $160 from Matt, on condition that she buys at least 100 kilograms. From another supplier, Robert, she can buy small quantities of corn cobs (100

*asked on June 2, 2019* -
## Languagd Arts

Which of the following is the best reason to use visuals in a research presentation? A. To illustrate your main point in an engaging manner. B. To illustrate any topic with data in percentages. C. To show different ways of looking at the same information.

*asked on April 10, 2015* -
## Differential calculus

A gutter with trapezoidal cross section is to be made from a long sheet of tin 8 in wide by turning up one third of its width on each side , what width a cross the top that will give a maximum capacity

*asked on August 23, 2015* -
## Chemistry

When copper(II) oxide is heated in the presence of hydrogen gas, elemental copper and water are produced. What mass of copper can be obtained if 34.0 g copper(II) oxide is used?

*asked on February 24, 2014* -
## Science

Does anyone know why does climate/water movement cause some parts of the ocean to be saltier than others? I'm stuck. Are there multiple ways?

*asked on April 3, 2019* -
## St paul's university

A sample of 200 voters revealed the following about the three candidates A,B and C.28 were in favour of both A and B.98 in favour of A or B but not C.42 in favour of B but not C or A.122 in favour of B or C but not A.64 in favour of C but not A or B.14 in

*asked on July 4, 2015* -
## Physics

Movers are looking to lower a cabinet out of an open window to a mattress on the ground below. One end of a rope is tied to a 188 kg dresser, looped through a pulley, and the other end of the rope is tied to a cabinet. If the coefficient of kinetic

*asked on October 20, 2016* -
## math

What is the volume of the cone in the picture if S = 5 and R = 3?

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

There are 24 students in Mrs.Smith's 1st block class. 1/4 of the class passed the math test with an A. 12 students in the class passed the math test with a B. What percent of the students in the class passed the test? ****** This is how I slove the

*asked on March 1, 2012* -
## Science (Chemistry)

2. Perform this operation and report the answer to the correct number of significant figures: What is the mass of a cube of aluminum that is 4.0 cm on each edge? The density of aluminum is 2.7 g/cm^3. Show all calculations leading to an answer. (I think I

*asked on March 9, 2015* -
## Math

By letting x=5^y, show that the equation p5^y + 5^-y = 5 can also be written as px^2-5x+1 = 0

*asked on February 9, 2017* -
## chemistry

Why is it necessary to wait until the filter paper containing a compound is completely dry before weighing it? and how would it effect the theoretical yield? HIgher?? lower??

*asked on May 6, 2010* -
## Physics

Sputnik, the first artificial satellite to orbit the Earth, had a mass of 83.6kg and travelled at 7574 m/s. The radius of the earth is 6371 km and its mass is 5.972 x 10^24 kg. What gravitational force did Sputnik apply to the earth during this orbit? What

*asked on February 22, 2017* -
## math

Later 7 students joined group 2 (41 students)and one student left to join group 1. (44 students) Now 20 students play trombone and 7 more students play trumpet as play saxophone. How many students play each instrument?

*asked on November 4, 2015* -
## Chemistry

Suppose a saturated solution of barium fluoride contains 1.5 x 10 ^ -2 M of F-. What is the Ksp of BaF2. I know that the balanced equation of this reaction is: BaF2 (s) --> Ba2+ (aq) + 2F- (aq) There is a 1:1 ratio between BaF2 and Ba2+ and there is a 1:2

*asked on March 31, 2016* -
## Language Arts

What is the most important reason for using multiple sources in a research presentation? A. So you include primary and secondary sources. B. So you have experience conducting original research. C. So you know that the information is accurate. D. So you use

*asked on April 10, 2015* -
## algebra

TGIF. Chris and Terry have been trying to live within their budget but miss going out to dinner on Friday nights. They decide not to spend any nickels or quarters they receive as change for a month and save these in a jar. At the end of the second week

*asked on July 17, 2011* -
## AP Human Geography

Without a scale on a map, A. many details must be omitted. B. only global trends can be captured. C. regional details can be captured, but larger details must be omitted. D. viewers cannot tell how much area on Earth is represented on the map. E. viewers

*asked on August 29, 2019* -
## Physics

A uniform ladder of 5.0 m long and 12 kg is leaning against the wall (contact with the wall = point b, contact with the floor = point a). The height from the ground to point b is 4m . The wall is frictionless but the floor is not. A painter of 55 kg climbs

*asked on February 24, 2013* -
## CHEMISTRY

The major component of vinegar is acetic acid CH3COOH. Which of the following reactions represents the balanced equation between acetic acid and sodium bicarbonate? a. CH3COOH(aq) + NaHCO3 a CH3COONa(aq) + CO2(g) + H2O(I) b. CH3COOH(aq) + 2 NaHCO3(aq) +

*asked on May 9, 2010* -
## Geometry

What is the scale factor of a dilation centered at the origin that maps the point (12, -8) to the point (-7.2, 4.8)? Please show work as it will help me better understand, thanks so much!

*asked on September 30, 2019* -
## Physics

A wind turbine rotates at 8.40 rpm and has an angular acceleration of 0.0326 rad/s2. If the wind turbine takes 27.0 s to come to a complete stop, how many revolutions will this take?

*asked on September 29, 2016* -
## Math

While mixing a light green paint, Luke mixes 35% blue paint and the rest is yellow. The green paint fills up two fifths of a litre container. Still thinking it needs to be a lighter green how much more yellow paint must be added to make the yellow paint

*asked on May 24, 2019* -
## Math

What is the Distributive Property?

*asked on October 12, 2015* -
## Chemistry

What are the molality and mole fraction of solute in a 32.3 percent by mass aqueous solution of methanol (CH3OH)? molality = ?m mole fraction =

*asked on March 13, 2014* -
## Science (Chemistry)

The Average density of Earth is 5.52g/cm^3. What is its density in a. kg/m^3 b. lb/ft^3. Please help me set up these equations. Thank you!

*asked on June 13, 2011* -
## Geometry

If AD=27, AC=2x, BC=3, and BD=x, what is x?

*asked on September 29, 2019* -
## Physics...Help!!!

given that Earth's surface gravitaitional field strength has a magnitude of 9.80N/kg, determine the distance(as a multiple of Earth's radius re) above the Earth's surface at which the magnitude of the field strength is 3.20N/kg.

*asked on December 20, 2012* -
## math

al has twice as many baseball cards as frank and four times as many football cards as joe. the expression 2x+4y can be used to show the total number of baseball and football cards Al has. If the answer is y, then what is the question?

*asked on August 17, 2012* -
## physics

A proton moves at a speed of 5.9 × 107 m/s at right angles to a magnetic field with a magnitude of 0.095 T. Find the magnitude of the acceleration of the proton. Answer in units of m/s 2 .

*asked on May 6, 2019* -
## Math help ❤️

An angel measures 53°. What are the measures of the angles comp meant and supplement? A) Comlement, 37°; supplement, 137° B) Complement, 127°; supplement, 47° C) Complement, 37°; supplement, 127° D) Complement, 127°; supplement, 37° Please help me

*asked on March 1, 2019* -
## Social Studies

What was the Peloponnesian war? Please check my answer :) A) A conflict between Greece and Persia B) A conflict between Athens and Sparta (my answer) C) A conflict between Greece and Macedonia D) A conflict between Macedonia and Athens Please help me my

*asked on February 18, 2019* -
## Math

Biruk wants to buy a book for $15.25 and a book for $4.85. He wants to pay with one $20.00 bill. Use estimation to decide whether this is reasonable or not. Explain what place value to round for an estimate this is useful in this situation.

*asked on October 12, 2015* -
## CHEMISTRY

The specific heat capacity (cp) of lead is 0.13 J/g °C. How much heat (in J) is required to raise the temperature of 15 grams of lead from 22 °C to 37 °C? a. 2.0 b. -0.13 c. 0.13 d. 29

*asked on May 9, 2010* -
## physics

An electron in a vacuum is first accelerated by a voltage of 15600 V and then enters a region in which there is a uniform magnetic field of 0.689 T at right angles to the direction of the electron’s motion. What is the force on the electron due to the

*asked on May 6, 2019* -
## math

Suburban Population. The following charts show the populations for two suburbs from 1980 to 1990, where x = 0 correspond to 1980, x = 2 correspond to 1982, and so on. Year x Suburb 1 y Year x Suburb 2 y 0 12,690 0 23,112 2 12,071 2 23,893 4 13,463 4 24,674

*asked on July 17, 2011*