# Charles

Most popular questions and responses by Charles-
## General Physics 1

A force ~F = Fx ˆý+Fy ˆ| acts on a particle that undergoes a displacement of ~s = sx ˆý + sy ˆ| where Fx = 10 N, Fy = −4 N, sx = 6 m, and sy = 1 m. 1. Find the work done by the force on the particle. Answer in units of J 2. Find the angle between

*asked on July 26, 2013* -
## probability theory

3 students; A, B and C, are in a swimming race. A and B have the same probability of winning and each is twice as likely to win as C. Find the probability that B or C wins the swimming race. 3) Given three boxes as follows: Box A contains 3 red, 2 white

*asked on November 20, 2015* -
## math

taryn and alastair both mow lawns. Each charges a flat fee to mow a lawn. The table shows the number of lawns in the past week, the time spent mowing lawns and the money earned. Taryn mowed 9 lawns. She spent 7.5 hrs mowing lawns. Taryn earned $112.50

*asked on December 3, 2014* -
## Physics

A baseball player leads off the game and hits a long home run. The ball leaves the bat at an angle of 30.0o from the horizontal with a velocity of 40.0 m/s. How far will it travel in the air? Working out please

*asked on March 17, 2015* -
## decimals

Mark wants to paint a mural. He has 1 1/3 gallons of yellow paint, 1 1/4 green paint, and 7/8 gallon of blue paint. mark plans to use 3/4 gallon of each paint color. How many gallons of paint will he have left after painting the mural?

*asked on November 18, 2014* -
## chemistry

Calculate the mass of oxygen (in mg) dissolved in a 5.00 L bucket of water exposed to a pressure of 1.13 atm of air. Assume the mole fraction of oxygen in air to be 0.21 and the Henry's law constant for oxygen in water at this temperature to be 1.3 x 10-3

*asked on May 26, 2014* -
## chem

How would your experimental formula of magnesium chloride “MgClx” have been affected if your product was not dried completely before weighing it? Would “x” be too high or two low?

*asked on October 28, 2015* -
## science

I am doing a titration lab and need help with a problem. (i used .100M H2SO4)(I used 10.0 ml of Ba(OH)2 solution and added 50.0 ml of distilled water making 60.0 ml total.) 1. Use the titration results to calculate the moles of H2SO4 that were used to

*asked on October 12, 2013* -
## General Physics

A 7453 N piano is to be pushed up a(n) 4.04 m frictionless plank that makes an angle of 25.9 with the horizontal. Calculate the work done in sliding the piano up the plank at a slow constant rate. Answer in units of J

*asked on July 26, 2013* -
## Physics

Find the sum of vectors A=5m

*asked on March 8, 2016* -
## PHYSICSI

The rotating loop in an AC generator is a square 11.0 cm on a side. It is rotated at 60.0 Hz in a uniform field of 0.800 T. Calculate the following quantities as functions of time t, where t is in seconds. (a) the flux through the loop mT·m2 (b) the emf

*asked on December 2, 2011* -
## Physics

Laser Pointers emit light waves whose wavelength is 670 nm. What is the frequency for this light?

*asked on February 23, 2012* -
## math

A girl starts from point A and walks 285m to B on a bearing of 078.She then walks due south to a point C which is 307m from A. What is the bearing of A from C,and what is {BC}? please i need the answer urgent ooo it is an assignment pls help me fast

*asked on May 18, 2017* -
## english

Choose the correct sentence pattern for the sentence below. I hereby declare Tuesday Shakespeare Day.

*asked on April 19, 2015* -
## math

Dents and Dings Auto Body buys paint with a list price of $29,000. If the supplier extends trade discounts of 30/35/20, what is the trade discount amount?

*asked on August 24, 2013* -
## Math/Trig

Which logarithmic equation is equivalent to L^m = E 1) LogL E = m 2) logE L = m 3) logm E= L 4) logE m= L

*asked on February 11, 2012* -
## Math

How many times does a palindromic number appear on a 12 hour digital clock between 12 midnight and 12 noon?

*asked on October 18, 2016* -
## physic

A 69-cm-diameter wheel accelerates uniformly about its center from 150rpm to 320rpm in 4.4s . Determine angular acceleration?

*asked on March 29, 2014* -
## Physics

“Strontium-90 is a pure beta source.” How could a physicist test this statement? I am stuck on this one, but I was thinking through measurement of radioactivity.

*asked on August 30, 2013* -
## physics

A small airplane with a wingspan of 13.5 m is flying due north at a speed of 70.8 m/s over a region where the vertical component of the Earth's magnetic field is 1.20 µT downward. (a) What potential difference is developed between the airplane's wingtips?

*asked on December 2, 2011* -
## Literature, History, Government, French

Explain 5 measures that the government of Ghana is taking to promote science education in Ghana

*asked on November 21, 2018* -
## Chemistry

A piece of wood sinks in ethanol but floats in gasoline. Give a range of possible densities for the wood?

*asked on September 20, 2007* -
## Chemistry

An increase in the average kinetic energy of a sample of copper atoms occurs with an increase in a- Concentration b- Pressure c- Volume d- Temperature

*asked on March 5, 2008* -
## Chemistry

What volume of carbon tetrachloride (density = 2.71 g/mL) contains 2.46x10^25 chlorine atoms?

*asked on March 29, 2015* -
## math

Melina walked her dog 2 1/5 miles. Cathy walked her dog 1 3/4 times as far as Melania did. How many more miles did Cathy walk her dog?

*asked on November 15, 2014* -
## math

protein = 4 calories per gram carbohydrate = 4 calories per gram fat = 9 calories per gram A serving of chicken has 27 grams of protein and 3 grams of fat. How many calories are in a serving of chicken?

*asked on May 7, 2019* -
## GRANTHAM

Find the present value of the ordinary annuity. Please round the answer to the nearest cent.$2,000 per semiannual period for 7 yr at 12%/year compounded semiannually

*asked on December 30, 2014* -
## Trigonometry

This is a logs question If u=x/y^2, which expression is equivalent to log u? 1) log x + 2 log y 2) 2(log x- log y) 3) 2(log x + log y) 4) log x- 2 log y

*asked on February 11, 2012* -
## MATH

Which ordered pairs are on the line 4x−3y=84x−3y=8 ? Select each correct answer. (−1,4) (1,−4/3) (3/2,−2/3) (−4,−8) I know that one is (1,4/3) but I thought the other was (2,0) and it is not up their. Help

*asked on January 19, 2018* -
## Science

The solubility of a compound in water is 6.8g/100ml at 25°C.. Calculate the amount of water required to crystallize 10g of the compound. If the pure compound is collected at 25°C what is the maximum possible yield percent.

*asked on September 21, 2015* -
## chemistry

A generic salt, AB, has a molar mass of 293 g/mol and a solubility of 2.20 g/L at 25 °C. What is the Ksp of this salt at 25 °C?

*asked on March 26, 2013* -
## math

The given box plots show the number of text messages Paul and Sally received each day on their cell phones. Select the true statement. A. The interquartile range of Paul's data is less than the interquartile range of Sally's data. B. The median of Paul's

*asked on May 21, 2019* -
## Math

Solve the equation sin2x=2cos2x, for 0 degrees

*asked on January 14, 2013* -
## Physics

A man walks 3km E and then 4km N. What is his resultant displacement?

*asked on March 8, 2016* -
## Algebra 2

Randy wants to collect 515 baseballs cards. Each week Randy buys 15 baseball cards. a. Create a table to represent this situation where t is the amount of time in weeks and c is the number of cards that Randy still wants to buy. b. Write an equation to

*asked on June 10, 2019* -
## Combinations and Permutations

A committee of 3 members is selected from a club made up of 10 junior members and 20 senior members. What is the expected number of juniors in the committee?

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

A jar contains 133 pennies. A bigger jar contains 1 2/7 times as many pennies. What is the value of the pennies in the bigger jar

*asked on November 23, 2014* -
## chemistry

A 0.109g sample of a pure gaseous compound occupies 112ml at 100degrees and 750torr: what is the molecular weight of the compound. ANS=(30.2g,mol). Please I need the solution

*asked on March 21, 2016* -
## physics

the surface tension Y, of liquid depends on the density,P, acceleration of gravity,g, and the height, h. use the method of dimension to derive the actual relationship between these quantities

*asked on March 7, 2016* -
## physics

consider a vertical piston system. the piston has a 50g mass and a given radius of 3mm. what amount of pressure does the piston exert? ( use g==9.8 m/s^2 )

*asked on June 2, 2015* -
## General Physics

A block sliding on a horizontal surface has an initial speed of 0.5 m/s. The block travels a distance of 1 m as it slows to a stop. What distance would the block have traveled if its initial speed had been 1 m/s? 1. 2 m 2. 1 m 3. more information is needed

*asked on July 26, 2013* -
## social studies, slaves, industrial revolution

Give an example of how being able to communicate over long distances would help Americans(using morse code)

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

On a part-time job, you are asked to bring a cylindrical iron rod of length 91.9 cm and diameter 2.70 cm from a storage room to a machinist. Calculate the weight of the rod, w.

*asked on August 14, 2011* -
## Social Studies 4

Why was Churchill concerned about Soviet influence and control from Moscow? http://www.loc.gov/exhibits/churchill/wc-coldwar.html http://en.wikipedia.org/wiki/Origins_of_the_Cold_War#The_breakdown_of_postwar_peace_.281945-1947.29

*asked on April 18, 2007* -
## Algebra 2

Water towers are tall to provide enough water pressure to supply all of the houses and businesses in the area of the tower. Each foot of height provides 0.43 psi (pounds per square inch) of pressure. a. Write a sequence for the pressure in psi for each

*asked on June 10, 2019* -
## math, log, interest, precalc

Investment: collectable toys Current yield 5% per month Rick: Extreamly high Your inital value is 1000 dollars what is the doubling time, time to reach 1800, and value after 10 years?

*asked on March 19, 2019* -
## Physics 204

I have a few questions. 1.The coefficient of sliding friction between steel skate blades and ice is .05. How much force must be applied to a 150lb. skater to maintain a constant velocity? 2. If it takes a force of 6 pounds to cause a 24 pound box to slide

*asked on January 21, 2008* -
## chemistry

In the combustion of hydrogen gas, hydrogen reacts with oxygen from the air to form water vapor. If you burn 54.8 g of hydrogen and produce 4.90 × 102 g of water, how much oxygen reacted?

*asked on August 29, 2014* -
## Thermodynamic

One mole of CO2 is to be compressed adiabatically from 1 bar and 25 C. Because of irreversibilities and poor design of the compressor the compressor work required is found to be 25 %greater than that for a well-designed (reversible) compressor. Compute the

*asked on March 8, 2016* -
## Physics

You are given vectors A = 5.0i - 6.5j and B = -2.5i + 7.0j. A third vector C lies in the xy-plane. Vector C is perpendicular to vector A and the scalar product of C with B is 15.0. Find the x and y components to vector C. Answer key shows x component is

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

what should you not do if you want to help get rid of graffiti

*asked on October 26, 2008* -
## science

A family in Virginia drove to California. The first day, they traveled 400 miles in 8 hours what is their velocity?

*asked on November 19, 2018* -
## Physics

A body is projected such that the horizontal range is twice the maximum height of projection. Find the angle of projection; and the time of flight if the velocity of projection is 5m/s

*asked on March 7, 2016* -
## Physics

If D=7i-3j+2k and E=4i+5j-3k. Find the scalar product of D.E

*asked on March 8, 2016* -
## Math

Delia has 493 stamps in her stamp collection. She can put 16 stamps on each page of an album. How many pages can she fill completely?

*asked on January 21, 2015* -
## General Physics

A 0.377 kg bead slides on a curved wire, starting from rest at point A(4.8 meters) as shown in the figure. The acceleration of gravity is 9.8 m/s2 . A. If the wire is frictionless, find the speed of the bead at B(0 Meters). Answer in units of m/s B. Find

*asked on July 26, 2013* -
## English 12

One goal of America Recycles Day is to raise awareness of the growing landfill problem. Which of these phrases is the complete infinitive phrase in the sentence?

*asked on November 6, 2018* -
## math

Nutritional Information: protein = 4 grams, carbohydrate = 4 grams, fat = 9 grams. If a banana has 27 grams of carbohydrates and a total of 121 calories. How many of its calories come from sources other than carbohydrates?

*asked on May 8, 2019* -
## physics

a sphere of radius r moving with velocity v through a fluid experiences a retarding force f given by F=6r^yv^zn^x where n is the viscosity of the liquid. use the method of dimensions to find the values of x,y,and z.

*asked on March 7, 2016* -
## General Physics

A force Fx acts on a particle. The force is related to the position of the particle by the formula Fx = (5.9 N/m3) x3. Find the work done by this force on the particle as the particle moves from x = 0.9 m to x = 22 m. Answer in units of J

*asked on July 26, 2013* -
## Physics

What is the total time of flight of an object projected vertically upwards with a speed of 30m/s? (g=10m/s^2

*asked on March 7, 2016* -
## Calculus-Derivatives

How is 6#sin(#x-1)/cos^3(#x-1) the derivative of f(x)= 3sec^2(#x-1)? #= Pi (I coulnd't find the symbol...sorry.)

*asked on September 28, 2008* -
## Math

7th percent intrest semianually give values for the follow amount of time -0.5 1 1.5 2 2.5 3

*asked on March 19, 2019* -
## logarithm, precalculus, algebra 2

how do you solve logarithms with log in the exponent?

*asked on February 11, 2019* -
## Advanced Finance

6. (TCO F) Suppose the December CBOT Treasury bond futures contract has a quoted price of 80-07. What is the implied annual interest rate inherent in the futures contract? Assume this contract is based on a 20-year Treasury bond with semiannual interest

*asked on November 21, 2014* -
## chemistry

a gas occupies a volume of 50.0mL at degrees Celsius and 630mmHg.at what temperature in degrees Celsius would the pressure be 101.3kPa if the volume remains constant?

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

The winner of a raffle will receive 3/4 of the 530.40 raised from raffle ticket sales

*asked on January 22, 2015* -
## General Physics

A 4 kg block slides along a frictionless horizontal with a speed of 5.1 m/s. After sliding a distance of 7 m, the block makes a smooth transition to a frictionless ramp inclined at an angle of 13 degrees to the horizontal. The acceleration of gravity is

*asked on July 26, 2013* -
## Chemistry

Some properties of aluminum are summarized in the following list. normal melting point 658°C heat of fusion 0.395 kJ/g normal boiling point 2467°C heat of vaporization 10.52 kJ/g specific heat of the solid 0.902 J/g°C (a) Calculate the quantity of

*asked on May 1, 2010* -
## Math

A table tennis ball is dropped from a height of 5ft. The ball rebounds to 60% of its previous height after each bounce. Write an infinite geometric series to represent the distance that the ball travels after it initially hits the ground. (hint, the ball

*asked on June 11, 2019* -
## Chemistry

If 84.1 g of sodium hydroxide are reacted with 51.0 g of aluminum in the following equation: 2NaOH + 2Al + 2H2O --> 2NaAlO2 + 3H2 a) what mass of excess reactant remains? b) what mass of water would react?

*asked on March 28, 2015* -
## Social Studies 2

What were the closest non-Communist European countries to the Soviet Union? Finland had a long history of trade and cordial diplomatic relations with the Soviet Union. After 1984, France, Austria, the Federal Republic of Germany (West Germany), and Italy

*asked on April 18, 2007* -
## Chemistry

Can someone please help me answer these questions? Is additional information other than what is given needed to solve? Thanks in advance. 1) Calculate the PH of a buffer containing 0.100 M propanoic acid, HC3H5O2 and .100 M NaC3H502 after the following

*asked on December 13, 2013* -
## Logic

Choose the pair of words/phrases among the choices that exhibits the same logical relationship as the words/phrases in the following pair. heavy : weight dry : wet feather : scale #hot : temperature color : size I placed a # next tom my answer.

*asked on September 11, 2011* -
## Science

A 0.5kg mass connected to a light spring of constant 20N/M occilates on a frictionless track. Calculate the total energy of the system

*asked on September 23, 2016* -
## Programming Logic and Design

Design an application that accepts eight friends' first names and displays them in alphabetical order

*asked on December 3, 2015* -
## Physics

A stone projected vertically upward with a speed of 30ms from the top of a tower of height 50m neglecting the air resistance.determine the maximum height it reach from the ground

*asked on August 5, 2014* -
## math

Bairleys rectangular dog pen for his irish setter must have an area of 400 square feet. Also the length must be 50 feet longer than the width. Find the dimentions of the pen

*asked on November 21, 2011* -
## stat

the time between unplanned shutdowns of a power plant has an exponential distribution with a mean of 20 days. Find the probability that the time between two unplanned shutdow is a) less than 14 days B) more than 21 days c) less than 7 days

*asked on January 11, 2011* -
## Chemistry

How do you prepare 17.2cm³ of 36% conc HCL per dm³ of solution?

*asked on April 1, 2017* -
## math

In isosceles right triangle ABC, point D is on hypotenuse BC such that AD is an altitude of triangle ABC and DC = 5. What is the area of triangle ABC?

*asked on July 7, 2016* -
## Chemistry

Determine the theoretical and percent yield of hydrogen gas if 78.5 g water undergoes electrolysis to produce hydrogen and oxygen and 3.23 g hydrogen is collected.

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

Hello im kinda new here and hoping someone can help me with this energy conservation question (I believe). A 2.10g- bullet embeds itself in a 1.30kg - block, which is attached to a spring of force constant 770 N/m . 1) If the maximum compression of the

*asked on November 19, 2009* -
## Physics - electricity

An incandescent lamp is marked '120v,75W' a)what is the current in the lamp under normal condition of operation? b)How much does it cost per hour to operate the lamp if the price of electrical energy is $6.00 per unit? Please stop posting under different

*asked on April 17, 2007* -
## physics

If a man weighs 600 N on the Earth, what would he weigh on Jupiter, where the free-fall acceleration is 25.9 m/s2?

*asked on February 10, 2019* -
## Chem

The brilliant color of fireworks is produced by shells containing lithium carbonate (Li2CO3) that are launched into the night sky and explode. The explosions produce enough energy to vaporize the Li2CO3 and produce excited state lithium atoms. These atoms

*asked on December 13, 2017* -
## math

The length by the width of Roxie's photo is 24 cm long and 14 cm wide. In order to make a photo that will fit into a wallet, the photo needs to be reduced to a length of 7 cm. Determine the width of the wallet size photo.

*asked on January 30, 2017* -
## Physics

Find the vector cross product of two vectors C=2i-j and D=i+2j-3k. What is the angle between the vectors

*asked on March 8, 2016* -
## Chemistry

Steam is compressed reversibly to liquid water at the boiling point 100C. The heat of vaporisation of water at 100C and 1.01325 bar is 2258Jg^-1. Calculate for one mole of water in term of work done(w),q,H and U for the process

*asked on April 8, 2012* -
## Chemistry

A laser emitting light with a wavelength of 480 nm is directed toward the surface of rubidium metal. The work function for rubidium metal is 2.16 eV (1 eV = 1.602 x 10-19 J)

*asked on November 16, 2010* -
## Chemistry

The density of water is 1.0 g/mL. How many deciliters of water will fill a 0.5-L bottle?

*asked on September 20, 2007* -
## Maths-Vectors Help!

Please can you help me as I have just been introduced to your Help Forum: Determine whether the vectors u, v and w given below are linearly independent or dependent where u, v and w are non-colliner vectors such that u=2a-3b+c , v=3a-5b+2c and w=4a-5b+c.

*asked on April 16, 2007* -
## math

A man walks due west for 4km. He then changes direction and walks on a bearing of 179 until he is south-west of his starting point.How far is he then from his starting point?

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

3. The population of Columbus, Ohio, in 2014 was about 823,000. The population of the United States was about 319 million in 2014. (a) Write each population in scientific notation. (b) About how many times larger was the population of the United States

*asked on September 20, 2016* -
## physic

If wind blows at 34m/s over a house, what is the net force on the roof if its area is 170m2 and is flat? (At 20 ∘ C dry air has a density of 1.2 kg/m3).

*asked on April 7, 2014* -
## General Physics

A spring with spring constant of 28 N/m is stretched 0.2 m from its equilibrium position. How much work must be done to stretch it an additional 0.06 m? Answer in units of J

*asked on July 26, 2013* -
## Chemistry

According to Solubility guidelines chemistry reference table, which of these salts is least soluble in water? a- PbCl2 b- RbCl c- LiCl d- FeCl2

*asked on March 5, 2008* -
## physics

A lawn tractor tire turns at 65rpm and has a radius of 13cm. What is the linear speed of the tractor in m/s?

*asked on February 6, 2008* -
## English

Two types of biographies are: a. Formate and genre b. Poetry and prose. c. Fiction and nonfiction. d authentic and fictionalized

*asked on May 4, 2017* -
## math

The mean of Alice's last 5 math test scores is 88. The first 4 of these 5 math test scores were 87, 75, 93, and 85. What score did Alice earn on her fifth math test?

*asked on January 27, 2017*