# Bobby

Popular questions and responses by Bobby-
## precalculus, complex numbers

Let $\omega$ be a complex number such that $\omega^7 = 1$ and $\omega \neq 1$. Let $\alpha = \omega + \omega^2 + \omega^4$ and $\beta = \omega^3 + \omega^5 + \omega^6$. Then $\alpha$ and $\beta$ are roots of the quadratic \[x^2 + px + q = 0\] for some

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

3. A person exerts a force of 55 N on the end of a door 74 cm wide. What is the magnitude of the torque if the force is exerted a)perpendicular to the door b)at a 45 degree angle to the door, c) at a 125 degree angle to the door?

*asked on November 4, 2010* -
## Chemistry

The heat of combustion of benzene, C6H6, is -41.74 kJ/g. Combustion of 3.65 of benzene causes a temperature rise of 4.41 C^o in a certain bomb calorimeter. What is the heat capacity of this bomb calorimeter? (kJ/C^o) So, I what I did was I multiplied

*asked on December 15, 2014* -
## Chemistry

The overall rate of any chemical reaction is most closely related to a) the number of steps in the reaction mechanism b)the overall reaction c) the fastest step in the reaction mechanism d)the slowest step in the reaction mechanism e) the average rate of

*asked on July 21, 2010* -
## physics

You throw a ball toward a wall with a speed of 25m/s and at an angleof 40 degree above the horizontal. The wall is 22m from the realease point of the ball. a) How far above the release point does the ball hit the wall? b) What are the horizontal and

*asked on October 25, 2006* -
## Chemistry

Does anyone know why Glucose is soluble in water but is not soluble in Hexane?

*asked on August 9, 2010* -
## Physics

An aluminum bar has the desired length when at 10 degrees Celsius. How much stress is required to keep it at this length if the temperature increases to 33 degrees Celsius?

*asked on November 14, 2012* -
## Calculus 1

A ball is thrown vertically upward from ground level with initial velocity of 96 feet per second. Assume the acceleration of the ball is a(t) = -32 ft^2 per second. (Neglect air Resistance.) (a) How long will it take the ball to raise to its maximum

*asked on December 3, 2018* -
## Calculus

Find two numbers whose sum is 10 for which the sum of their squares is a minimum.

*asked on December 16, 2008* -
## Math

a. Express f(x)=x^2 - 6x + 14 in the form f(x)=(x-h)^2 + k, where h and k are to be determined. b.Hence, or otherwise, write down the coordinates of the vertex of the parabola equation y=x^2 - 6x + 14.

*asked on December 9, 2012* -
## Writing English

PLEASE HELP Does my work look correct? Underline the adverb clause in each sentence below, and then answer the questions that follow. 12. When rain falls, my socks get wet. I underlined "my socks get wet" as the adverb clause a. What word (or words) does

*asked on February 16, 2019* -
## Math

Use a specific example to explore how the cross product behaves under scalar multiplication. Is it true that k (Vector a × Vector b) = (kVector a) × Vector b = Vector a × (kVector b)? Expand to the general case to prove your theory.

*asked on September 25, 2018* -
## physics please help!!

A diver stands on the end of a diving board as shown in the figure on the right. The mass of the diver is 58 kg and the mass of the uniform diving board is 35 kg. Calculate the magnitudes and directions of the forces exerted on the board at the points A

*asked on March 24, 2014* -
## Chemistry

In a saturated solution of silver phosphate, the concentration of silver ion is 4.5 x 10^-4 mol/L. The Ksp of silver phosphate would be which of the following? 6.8 10-8 1.0 10-11 1.4 10-14 none of the above 1.5 10-15 In a saturated solution

*asked on March 12, 2010* -
## physics

A paperweight, when weighed in air, has a weight of W = 6.8 N. When completely immersed in water, however, it has a weight of Win water = 4.3 N. Find the volume of the paperweight.

*asked on December 11, 2009* -
## Physics

You are pulling your little sister on her sled across an icy (frictionless) surface. When you exert a constant horizontal force of 120 N, the sled has an acceleration of 1.7 m/s2 If the sled has a mass of 8.4 kg, what is the mass of your little sister?

*asked on October 13, 2014* -
## calculus 2

Find the volume of the solid formed by rotating the region enclosed by y=e^(5x) , \ y=0, \ x=0, \ x=0.8 around the y-axis Please help, i have been attempting these problems for a couple of days

*asked on September 21, 2012* -
## math, calculus 2

Consider the area between the graphs x+y=16 and x+4= (y^2). This area can be computed in two different ways using integrals. First of all it can be computed as a sum of two integrals integrate from a to b of f(x)dx + integrate from b to c of g(x)dx What is

*asked on September 12, 2012* -
## Chemistry

Wh does the blue color of Iodine disapear when amylose reacts with saliva? I had thought it was because Amylase in saliva will replace the I2 in the amylose coil and thus removes the color, but I got it wrong. I know it has to be connected to the Amylase

*asked on August 8, 2010* -
## chemistry

Assuming that 1 gram of aspirin dissolves in 450 ml of water at 10°C, how much aspirin would be lost in 40 ml of water added to the reaction mixture if the mixture were at 10 °C during filtration?

*asked on April 20, 2010* -
## science

*Please answer quickly!* 1. Nucleic acids include RNA and DNA. The monomers of these molecules are ____. a fatty acids b amino acids c nucleotides d monosaccharides 2. Phospholipid molecules in a membrane are arranged with their ______ on the exterior and

*asked on December 10, 2019* -
## English

Check my work? Underline the adverb clause in each sentence below, and then answer the questions that follow. 13. My grandma always yells at me because I only own two pairs of socks. I underlined " I only own two pairs of socks " as the adverb clause a.

*asked on February 16, 2019* -
## Math

In the NFL, a division consists of 4 teams, each of which plays each other team twice. Assume that in any game, either team is equally likely to win (and there are no ties). What is the probability that, at the end of the season, the division has neither a

*asked on June 17, 2016* -
## Chemistry

Silicon carbide, commonly known as carborundum, is a very hard and abrasive substance. The compound is prepared by heating silicon dioxide in the presence of graphitic carbon: SiO2(s) + 2C(s) --> SiC(s) + CO2(g) How many grams of silicon carbide can be

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

the pressure (p) that a 160-pound person's shoe exerts on the ground when walking varies inversely with area (a) of the sole of the shoe. when the shoes have a sole area of 40 sq. in., the pressure is 4 pounds per sq. in. what is the sole area of the sole

*asked on March 3, 2012* -
## Math

22/8 - 3/2

*asked on January 31, 2020* -
## Language Arts

Which of the following answer choices contains a METAPHOR? a. His skin was sandpaper. b. The sun sparkled like a diamond. * c. Sh wanted to be like the birds and fly away. d. They felt free when they ran through the doors. What is a key characteristic of a

*asked on January 14, 2016* -
## chemistry

Bromine is a red liquid at 25°C. Its density is 3.12 g/mL. What is the volume of 28.1 g of liquid bromine?

*asked on May 4, 2015* -
## math

The Sugar Sweet Company will choose from two companies to transport its sugar to market. The first company charges $ 4696 to rent trucks plus an additional fee of $ 225.50 for each ton of sugar. The second company charges $ 5500 to rent trucks plus an

*asked on April 25, 2015* -
## Organic Chemsitry

By knowing the natural abundance of minor isotopes, it's possible to calculate the relative heights of M+ and M+1 peaks. If natural abundances are 12C - 98.9% and 13C - 1.10%, what are the relative heights, to the nearest 0.1%, of the M+ and M+1 peaks in

*asked on January 27, 2012* -
## chem

Suppose it takes 35 min for 4.0 g of sugar to completely react with another reagent added to the flask. What would the reaction rate be?

*asked on September 27, 2011* -
## Spanish

Complete each sentence with the correct form of the appropriate verb. Each verb will be used only once. hacer beber escribir compartir vender 1.Tú siempre agua después de correr. 2. Yo siempre la tarea después de las clases. 3. La cafetería unas

*asked on May 11, 2011* -
## physics

Two conductors are made of the same material and have the same length. They each have circular cross sectional areas. The ratio of their radii is 2:1. they carry the same current. What is the ratio of the electrical potential across their lengths? i know

*asked on April 22, 2009* -
## SCIENCE

THERE ARE THREE SOURCES OF RESISTANCE IN A PARALLEL CIRCUIT,S . TWO OF THEM ARE RATED AT 20 OHMS THE OTHER AT 10 OHMS WHAT IS THE CIRCUIT,S TOTAL RESISTANCE.

*asked on May 8, 2008* -
## mathematics

A cone-shaped pile of sawdust has a base diameter of 24 feet, and is 9 feet tall. Find the volume of the pile.

*asked on May 12, 2020* -
## English

Check my work? Underline the adverb clause in each sentence below, and then answer the questions that follow. 12. When rain falls, my socks get wet. I underlined "my socks get wet" as the adverb clause a. What word (or words) does the clause modify. My

*asked on February 16, 2019* -
## Language

In "Two Kinds", what changes the daughters attitude about becoming a prodigy? A. She sees her Brother disappointment after she fails the test . B. She realizes that she will have to learn to play the piano . C. She realizes that Waverley has a natural

*asked on August 26, 2017* -
## precalculus

Let $R$ be the set of primitive $42^{\text{nd}}$ roots of unity, and let $S$ be the set of primitive $70^{\text{th}}$ roots of unity. How many elements do $R$ and $S$ have in common?

*asked on February 15, 2017* -
## Physics

A diver stands on the end of a diving board as shown in the figure on the right. The mass of the diver is 58 kg and the mass of the uniform diving board is 35 kg. Calculate the magnitudes and directions of the forces exerted on the board at the points A

*asked on March 24, 2014* -
## science

Calculate the weight of a person with a mass of 67 kg that is holding a 12 kg box on earth

*asked on October 10, 2013* -
## physics

heading due north at 6.00 m/s relative to the water. The local ocean current is 1.53 m/s in a direction 40° north of east. What is the velocity of the ship relative to the earth?

*asked on January 31, 2013* -
## life

The first antibiotic was made because of properties discovered in a certain type of A. spider. B. mold. C. blood. D. herb.

*asked on January 11, 2013* -
## College Health Law

Following an automobile accident, a 16-year old boy who had recently escaped from a detention center was brought to the hospital emergency department by ambulance. The patient seemed to be alert and claimed to be suffering withdrawal symptoms from a drug

*asked on March 28, 2012* -
## Chemistry

What are the major organic products of this reaction: CH3CH2CH2COCH2CH3 (an O is double bonded to the C before the O) + H2O --> (acid is above the arrow) DrBob222- There are 2 oxygens. I said there is an O double bonded to the C. So there is the O after

*asked on March 21, 2010* -
## Algebra

If k(x) = 2x2 - 3, then k(9) is A) 321 B) 162 C) 159 D) 153

*asked on December 17, 2019* -
## Social studies

Which statement accurately describes the reasons for establishing Plymouth and Jamestown

*asked on February 26, 2019* -
## Vectors

Find the scalar equation of the plane through the points M(1,2,3) and N(3,2,-1) that is perpendicular to the plane with equation 3x + 2y + 6z +1 = 0.

*asked on October 11, 2018* -
## Algebra Word Problem

During summer vacation, c children went to different destinations with their parents. 36% of the children went to Europe and 24 children to Asia. The rest of the children went to South America. How many children went to South America?

*asked on April 19, 2017* -
## Math

A pencil costs $3.50 and a pen costs $6.70. Jessica bought m pens. She also bought 4 fewer pencils than pens. Write an algebraic expression for the total amount she spent. The answer supposed to be 6.70m + 3.5 (m-4). I got confused of what to do

*asked on February 3, 2017* -
## Math

A rectangular football field, including both end zones, is 120 yards long. The field has an area of 57,600 ft.². What is the width of the field in feet.

*asked on January 7, 2017* -
## maths

What is the sum of 4x dollars and 4x cents. Express your answer in cents .

*asked on July 16, 2015* -
## chemistry

Water has a density of 0.997 g/mL at room temperature (25 C). If you have exactly 500 mL of water, what is its mass in kg?

*asked on May 4, 2015* -
## algebra

A small painting has an area of 400 c m 2 . The length is 4 more than 2 times the width. Find the dimensions of the painting. Solve by completing the square. Round answers to the nearest tenth of a centimeter.

*asked on May 20, 2014* -
## health

To keep a positive attitude on the job, you should A. look for the perfect company—this will ensure everything will be all right. B. complain about the things that bother you so they can get straightened out. C. encourage others to help you with your

*asked on January 16, 2013* -
## health

If you work in a hospital or doctor's office and assign numeric values to procedures and diagnoses for the purpose of reimbursement, you are a A. coding specialist B. medical assistant C. receptionist D. transcriptionist

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

Decide whether to integrate with respect to x or y. Then find the area of the region: 2y=5sqrt(x), y=4, and 2y+2x=7.

*asked on September 11, 2012* -
## math

Let f(x)=((x^(6))*((x-8)^(2)))/((x2+4)^(7)) Use logarithmic differentiation to determine the derivative. f '(x) = f '(8) =

*asked on March 28, 2012* -
## Physics

A child's pogo stick stores energy in a spring with a force constant of 2.5×104N/m. At position A, the spring compression is a maximum and the child is momentarily at rest. At position B, the spring is in its equilibrium position and the child is moving

*asked on March 26, 2012* -
## Vectors

E and C kick a soccer ball at the same time. E kicks it with a force of 120 N at an angle of 60 degrees and C kicks it with a force of 200 N at an angle of 120 degrees. Calculate The magnitude and direction of the resultant force.

*asked on May 8, 2010* -
## math

you have 15 yards of ribbon for your gift boxes. each box gets the same amount of ribbon how much ribbon will each of your 20 gift boxes get?

*asked on August 20, 2008* -
## Algebra

Each of my sons has as many brothers as sisters, but each of my daughters has only half as many sisters as brothers. How many children do i have?

*asked on January 18, 2008* -
## PHYSICS

During a tennis match a player serves the ball at 23.6 m/s with the center of the ball leaving the raquet horizontally 2.37m abovet eht court surface. The net is 12m away and .9m high. When the ball reaches the net a) does the ball clear it and b) what is

*asked on October 24, 2006* -
## carbon!

Why is that carbon can form an infinite number of molecules? http://web.jjay.cuny.edu/~acarpi/NSC/10-organic.htm http://www.scienceclarified.com/everyday/Real-Life-Chemistry-Vol-2/Carbon.html http://biology.clc.uc.edu/courses/bio104/carbon.htm

*asked on June 13, 2006* -
## Math Calculus

A baseball team plays in a stadium that holds 58000 spectators. With the ticket price at $11 the average attendance has been 22000. When the price dropped to $10, the average attendance rose to 29000. Assume that attendance is linearly related to ticket

*asked on June 10, 2020* -
## Alg1

Diagonal of square 8 root 2. find length

*asked on May 26, 2020* -
## Chemistry

The solubility product for Ir3PO4(s) is: Ksp = 2.74 times 10^-18. Determine what the molar solubility is of Ir3PO4 in water?

*asked on May 14, 2020* -
## Physics

If the induced current decreases do the magnetic flux increase or decrease?

*asked on May 11, 2020* -
## Algebra

Amazon charges a flat rate of $129 (yearly) for Amazon Prime and $7.99 for each HD movie rental. Youtube Red charges a flat rate of $144 (yearly) and $4.99 for each movie rental. a) Write an equation to represent Amazon's charges. Explain how you got that

*asked on December 9, 2019* -
## Physics

A 150 gram mass is attached to a horizontally aligned spring on a frictionless surface. A force of 10 Newtons will stretch the spring 25 centimeters. If the spring is compressed to 15 centimeters and then released, calculate: the spring constant; the

*asked on May 1, 2019* -
## English

Check my work? Underline the adverb clause in each sentence below, and then answer the questions that follow. 15. The insect will drown when it crawls inside. I underlined " it crawls inside." as the adverb clause a. What word (or words) does the clause

*asked on February 16, 2019* -
## English (Check)

What type of question can the bolded text help you answer? My social studies teacher, Ms. Galvez, rolled her eyes at me and I rolled my eyes back at her. The Man was always coming down on me, just because I go through school firewalls like wet Kleenex,

*asked on September 26, 2017* -
## social studies

which principles are typically associated with the republican party? select all that apply A.limited government B.social justice C.progressive ideals D. traditional values

*asked on May 15, 2017* -
## Physics

When boiling water, a hot plate takes an average of 9 minutes and 47 seconds to boil 100 milliliters of water. Assume the temperature in the lab is 75 degrees Fahrenheit. The hot plate is rated to provide 195 watts. How efficient is the hot plate?

*asked on October 19, 2016* -
## Math

The cost for 3 dinners plus a 15% tip is $27.60. Write an equation representing the situation if p is the price of the dinner in dollars. You may asssume there is no tax.

*asked on September 9, 2016* -
## Physics

A ball is thrown horizontally from the building roof at a speed of 20 m/s. Takes ball 4 seconds to reach the ground. How tall is building? What is the ball’s speed and direction as it contacts the ground? How far from the base of the building does the

*asked on July 11, 2016* -
## Math

What is the range between 58 degrees and -88 degrees

*asked on March 16, 2016* -
## English

What roles are played by the female characters you encountered in this unit? Describe some of these female characters, their traits, and the roles they played within the selections you read, especially considering that all of those selections had male

*asked on February 29, 2016* -
## physics

Mayan kings and many school sports teams are named for the puma, cougar, or mountain lion Felis concolor, the best jumper among animals. It can jump to a height of 12.2 ft when leaving the ground at an angle of 44.2°. With what speed, in SI units, does it

*asked on February 15, 2016* -
## Algebra 2

A right triangle has a 45 degree angle. The hypotenuse is x and the leg is 8. Find the value of x.

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

Tell whether the lines for each pair of equations are parallel perpendicular or neither. Y= -2x + 4 -5+10y=5 I think perpendicular Next question is same kind- Y=-1/4x+10 -2x+8y=6 I think it's neither

*asked on December 12, 2015* -
## Algebra

Flying against the wind, an airplane travels 28 km in 5 hours. Traveling with the win, the same plane travels 3760km in 4 hours. What is the rate of the plane and still air and what is the rate of the wind?

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

Solve the following equations for x and check the solution using log. 2^6x-1 = 28 The answer is log56/6log2. Explain each step.

*asked on November 7, 2015* -
## chemistry

3A+2B+2C > 4D+2E 1) what is the rate of this reaction in terms of change of concentration of reactant B? - is it '1/2' ? 2) what is the rate of this reaction in terms of change of concentration of product D? please help

*asked on September 10, 2015* -
## statistics

the standard score for hours spent online at home for Minnesotans was 2.84. The mean equals 8.9 hours. Approximately how many hours do Minnesotan adults spend online at home.

*asked on February 4, 2015* -
## Science

When magnesium oxide (MgO) and water (H20)react, they produce magnesium hydroxide Mg(OH)2. Magnesium hydroxide is a medicine used to treat an upset stomach. The equation for this chemical change is shown below: MgO + H20 --> Mg(OH)2 if 40.00 grams of

*asked on December 11, 2014* -
## statistics

1)According to past record the average daily sales for a sporting goods store was $3456.00. After a new advertising campaign, the manager wants to see if the average daily sales have changed. A random sample of 20 days gives a sample mean of 3655 with a

*asked on December 6, 2014* -
## Physics

The atomic mass of a nitrogen atom (N) is 14.0 u, while that of an oxygen atom (O) is 16.0 u. Three diatomic gases have the same temperature: nitrogen (N2), oxygen (O2), and nitric oxide (NO). Rank these gases in ascending order (smallest first), according

*asked on October 27, 2014* -
## Physics

The cylinder in the drawing contains 3.81 mol of an ideal gas. By moving the piston, the volume of the gas is reduced to one-fourth its initial value, while the temperature is held constant. How many moles Δn of the gas must be allowed to escape through

*asked on October 27, 2014* -
## statistics

If a milk cow in California produced a mean of 1,875 pounds of milk per month, what percentage of production would that cow be in compared to the overall production per milk cow in California from 1990 through 2005?

*asked on August 19, 2014* -
## please help asap!

A ladder, 5.0 m long, leans against a frictionless wall at a point 4.0 m above the ground. A painter is climbing up the ladder. The mass of the ladder is 12.0 kg and the mass of the painter is 60.0 kg. The ladder begins to slip at its base when the painter

*asked on March 24, 2014* -
## economics

The demand curve for knobs is P=75-6QD and the supply curve for knobs is P=35+2QS. What is the equilibrium price of a knob?

*asked on December 20, 2013* -
## math

show that the equation x^3-15x+c=0 has at most one root on the interval [-2,2.

*asked on November 29, 2013* -
## biology

An individual with the genetic condition cystic fibrosis has CFTR protein with the amino acid histidine (at position 482), where the normal CFTR protein has arginine. (No other changes are observed in the protein.) This is the result of a _________

*asked on November 25, 2013* -
## biology

Which of the following is NOT true of transcription / translation processes in both bacteria and eukaryotes? Select one: a. RNA polymerase reads the template DNA strand to produce the complementary mRNA transcript. b. Translation of a polypeptide can occur

*asked on November 25, 2013* -
## chemistry

how do u hybridize for sulfate (SO4 -2)?

*asked on November 21, 2013* -
## phyics

A person who weighs 829 N steps onto a spring scale in the bathroom, and the spring compresses by 0.538 cm. (a) What is the spring constant? (b) What is the weight of another person who compresses the spring by 0.390 cm?

*asked on November 5, 2013* -
## phyics

You are installing a new spark plug in your car, and the manual specifies that it be tightened to a torque that has a magnitude of 65 N·m. Using the data in the figure, determine the magnitude F of the force that you must exert on the wrench.

*asked on November 1, 2013* -
## Chemistry

The protective action of ozone in the atmosphere comes through ozone's absorption of UV radiation in the 230 to 290 nm wavelength range. What is the energy, in kilojoules per mole, associated with radiation in the wavelength range?

*asked on October 22, 2013* -
## physics

The Space Shuttle travels at a speed of about 5.45 x 103 m/s. The blink of an astronaut's eye lasts about 111 ms. How many football fields (length = 91.4 m) does the Space Shuttle cover in the blink of an eye?

*asked on June 28, 2013* -
## Chemistry

What concentration of the salt NaC2H3O2 must be added to shift the equilibrium toward the reactants so that the [H3O+] concentration is reduced to pH = 5.4? Ka=1.8E-5

*asked on April 16, 2013*