# Erin

Most popular questions and responses by Erin-
## English

Read the following passage "I don't know anything," he said, "except that I'm beginning to be sorry we bought that room for the children. If children are neurotic at all, a room like that -" "It's supposed to help them work off their neuroses in a

*asked on May 2, 2016* -
## math

A hot air balloon descends at a rate of 320 feet per minute for 3 minutes. Whats the balloons total change in altitude?

*asked on May 17, 2013* -
## Social Studies

Hi Jiskha!! I have been researching the Civil war and wanted to know it you can add to this. No this is not my work it is essays and summary's i found on the computer, this is what I found: Summary of the Civil War: Fought 1861-1865, the American Civil War

*asked on November 10, 2010* -
## science

the density of an object with a volume of 60.0 mL and a mass of 400.0g is___? a. 0.150g/mL b. 2.89g/mL c. 5.50 g/mL or d. 6.67 g/mL

*asked on March 17, 2016* -
## statistics

the probability that a football game will go into overtime is 17%. In 240 randomly selected football games, what is the mean and the standard deviation of the number that went into overtime

*asked on June 23, 2013* -
## Physics

Liz rushes down onto a subway platform to find her train already departing. She stops and watches the cars go by. Each car is 8.60 m long. The first moves past her in 1.75 s and the second in 1.17 s. Find the constant acceleration of the train. I know how

*asked on October 10, 2009* -
## physics

The outstretched hands and arms of a figure skater preparing for a spin can be considered a slender rod pivoting about an axis through its center. When the skater's hands and arms are brought in and wrapped around his body to execute the spin, the hands

*asked on April 12, 2008* -
## Chemistry: help please

What is the millimolar solubility of oxygen gas,O2, in water at 20 degree celsius, if the pressure of oxygen is 1.00atm?

*asked on February 1, 2009* -
## physics

As you hurry to catch your flight at the airport, you encounter a moving walkway that is 85m long and has a speed of 2.2 m/s relative to the ground. If it takes you 68s to cover 85m when walking on the ground, how long will it take you to cover the same

*asked on October 2, 2011* -
## physics

An Astronaut on the Moon drops a rock straight downward from a height of 1.25 meters. If the acceleration of gravity on the Moon is 1.62 meters per second squared, what is the speed of the rock just before it lands?

*asked on October 1, 2011* -
## chemistry

Calculate the amount of heat required to completely sublime 24.0 g of solid dry ice CO_2 at its sublimation temperature. The heat of sublimation for carbon dioxide is 32.3 kJ/mol.

*asked on September 7, 2008* -
## Chemistry

At a particular temperature, K = 3.75 for the following reaction. SO2(g) + NO2(g) SO3(g) + NO(g) If all four gases had initial concentrations of 0.520 M, calculate the equilibrium concentrations of the gases

*asked on May 5, 2010* -
## Physics

The Lamborghini Murcielago can accelerate from 0 to 27.8 m/s (100 km/hr or 62.2 mi/hr) in a time of 3.40 seconds. How fast will the car be traveling (m/s) after 5.1 seconds.

*asked on February 22, 2014* -
## Chemistry

An alpha particle (mass 6.6 x 10^-24 grams) emitted by radium travels at 3.4 x 10^7 plus or minus 0.1 x 10^7 mi/h. (a) What is its de Broglie wavelength (in meters)? (b) Whats uncertainty in its position? for part (a) I got 1.53 meters which said it was

*asked on March 5, 2010* -
## chemistry

Consider the following reaction: 2HBr(g)---> H_2(g) + Br_2(g) B)In the first 15.0s of this reaction, the concentration of HBr dropped from 0.510M to 0.455M. Calculate the average rate of the reaction in this time interval. C)If the volume of the reaction

*asked on September 24, 2008* -
## Physics

A man of mass 75 kg lies on a bed of 10,000 nails. The tip of each nail has an area of 1.0 square millimeter. What pressure does the man experience? [g=10 N/kg]

*asked on April 12, 2014* -
## Algebra 2(check) cont..

1)solve the inequality -3(r-11)+15>_9 my answer = r

*asked on July 21, 2007* -
## Physics

An engineer in a locomotive sees a car stuck on the track at a railroad crossing in front of the train. When the engineer first sees the car, the locomotive is 170 m from the crossing and its speed is 25 m/s. If the engineer’s reaction time is 0.68 s,

*asked on September 26, 2019* -
## physical science

In raising a 5000-N piano with a pulley system, the movers note that, for every 2m of rope pulled down, the piano rises 0.3m. Ideally, show that the force required to lift the piano is 500-N.

*asked on February 28, 2012* -
## Languege arts

1. Which is the BEST summary of "LAFFF"? (1 point) Angela used a time machine to win a writing contest. Peter and Angela invented a time machine. Peter used a time machine to travel to the future. 2. The author describes Peter's Halloween costume in order

*asked on February 7, 2013* -
## Physics

A uniform bar length of 2.0m and weight 1000 N has its center of gravity at its center. The bar is pivoted 0.5m from the right, and supports a weight of 200N on the opposite end (left end). What is the weight needed at right end of the bar to balance the

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

The Coffee Counter charges $11.00 per pound for Kenyan French Roast coffee and $15.00 per pound for Sumatran coffee. How much of each type should be used to make aa 24 pound blend that sells for $13.00 per pound?

*asked on January 22, 2018* -
## biochemistry lab

A) If you make up a solution of 50 mL of 0.1 M TRIS in the acid form, what will be the pH? B) If you add 2 mL of 1M NaOH to the solution in part A, what will be the pH? If it is needed, here is some addition information: TRIS pka= 8.3 mw of TRIS-HCL= 157.6

*asked on February 2, 2008* -
## English

"I watched Hassan get raped," I said to no one. Baba stirred in his sleep. Kaka Homayoun grunted. A part of me was hoping someone would wake up and hear, so I wouldn't have to live with this lie anymore. But no one woke up and in the silence that followed,

*asked on December 2, 2012* -
## chemistry

what are the symmetry elements for: cis-CoCl2(NH3)4 and trans-CoCl2(NH3)4 would it be C2 S2?

*asked on February 25, 2009* -
## History

What impact did industrialization have on imperialism? a. Developing European nations needed to conquer foreign territory to compete with industrialized nations b. An increase in production lead to the need for new land to build factories in foreign

*asked on February 25, 2019* -
## Calculus

For an object whose velocity in ft/sec is given by v(t)=2sin(t),what is its distance,in feet, travelled on the interval t=1 to t=5?

*asked on January 27, 2019* -
## physics

A motorcycle stunt rider must jump a 100m wide canyon given a 20° ramp positioned on either side. What minimum speed is required so the rider will clear the canyon?

*asked on October 17, 2010* -
## Pre-Calculus

A piece of plexiglass is in the shape of a semi-circle with radius 2m. Determine the dimensions of the rectangle with the greatest area that can be cut from the piece of plexiglass?

*asked on March 28, 2010* -
## Chemistry

A pediatrician prescribes the antibiotic amoxicillin to treat a child suffering from an ear infection. The prescribed dose is to be 72.1 mg of drug per kilogram patient body mass per day. The drug is to be administered twice each day in the form of a

*asked on September 19, 2017* -
## Algebra

You operate a gaming Web site, where users must pay a small fee to log on. When you charged $3 the demand was 520 log-ons per month. When you lowered the price to $2.50, the demand increased to 780 log-ons per month. (a) Construct a linear demand function

*asked on February 21, 2012* -
## physics

There are two blocks connected by a string and tied to a wall on an incline. The mass of the lower block is 1.0kg; the mass of the upper block is 2.0kg. Given that the angle of the incline is 31*, find the tension in (a) the string connecting the two

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

A skateboarder at a skate park rides along the path. If the speed of the skateboarder at point A is v=1.4 m/s what is her speed at point B? Point A = 2.7 m & Point B=1.0 m

*asked on June 30, 2019* -
## Chem Help!!!

A 1.00 mL aliquot of solution A was diluted to 50.00 mL using 0.02 M Fe(III), forming solution B (reaction 2) By looking at this how many moles of sodium salicylate were in the 1.00 mL aliquot used to prepare solution B?

*asked on April 2, 2017* -
## chemistry

How do you do the hybridization of CBr4?

*asked on March 5, 2012* -
## Chemistry

We will calculate the amount of acid to use in each titration. Assume that you are using 0.0512 M NaOH(aq). A good volume of NaOH(aq) to use per titration is 15 mL. From this molarity and volume, the moles of NaOH can be calculated. Since the unknown acid

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

Suppose you pluck a string on a guitar and it produces the note A at a frequency of 440 Hz. Now, you press your finger down on the string against one of the frets, making this point the new end of the string. The newly shortened string has 4/5 the length

*asked on March 17, 2014* -
## Chem

Suppose a runner completes a 10K (10.0 km) road race in 42 minutes and 15 seconds. What is the runner's average speed in miles per hour?

*asked on September 17, 2017* -
## Algebra 2

The formula A = 180(n-2)/n relates to the measure A of an interior angle of a regular polygon to the number of sides n. If an interior angle measures 120 degrees, find the number of sides A)5 B)6 C)8 D)10 I have NO clue on how to do this pls help. Make A

*asked on July 15, 2007* -
## Math

How do you set this up? Solve the system using substitution: A boat travels 18 miles downstream in 1.5 hrs. It then takes the boat 3 hrs. to travel upstream the same distance. Find the speed of the boat in still water and the speed of the current. Thanks

*asked on December 6, 2012* -
## Chemistry

Calculate the wavelengths: -A muon (a sub particle with the mass of 1.884 X 10^-25g) traveling at 320.0 m/s -an electron (me=9.10939 x 10^-28g) moving at 3.85 x 10^6 m/s -An 83.0kg athlete running a "4 minute mile" (i.e. 400min/mile)

*asked on March 31, 2019* -
## Physics

The command module orbited at an altitude of 110 km above the lunar surface. How much time did it take for the command module to complete one orbit?

*asked on July 20, 2019* -
## Trig

The seats of a Ferris wheel are 40 feet from the wheel's center. When you get on the ride, your seat is 6 feet above the ground. How far above the ground are you after rotating through an angle of 17pi/4?

*asked on June 2, 2018* -
## Chemistry

The spectrophometer was used to measure the absorbance of each of a series of [FeSa]+ solutions. A standard curve was construnceted by plotting the absorbance vs. concentration (M). The slope and y-intercept were found to be 1496 M-1 and .003,

*asked on April 2, 2017* -
## Math

Jill said that an angle is made of any to rays is she correct explain

*asked on February 27, 2018* -
## physics

A point charge of -4.00nC is at the origin, and a second point charge of 6.00nC is on the axis at x = 0.800m . Find the magnitude and direction of the electric field at each of the following points on the axis. x_2 = 17.0cm, x_3 = 1.30m , x_4=-17.0cm

*asked on September 12, 2008* -
## Chemistry

Assuming that the unknown acid sample in question 1 had a mass of 0.177 g, what is the molar mass of the unknown acid?

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

A pilot flies out of Cleveland and sets his compass due North. He maintains an airspeed of 250 km/hr. After 30 minutes he finds that the plane is 200 km north and 40 km west of the starting point. What is the velocity of the wind? I've made my triangle and

*asked on January 26, 2016* -
## physics

A helicopter is rising at 5 m/s when a bag is dropped. After 2 seconds what is the bag's velocity? what is the bag's position? and how far below the helicopter is the bag?

*asked on September 21, 2011* -
## Stats

Running times for 400 meters is usually distributed for young men between 18 and 30 years of age with a mean of 93 seconds and a standard deviation of 16 seconds. What percent of runners with finish after 110 minutes?

*asked on April 17, 2019* -
## chemistry

will fe3+ oxidize Sn2+ to Sn4+ in acidic solution?

*asked on June 18, 2012* -
## Physics

A rock climber hangs freely from nylon rope that is 16 m long and has a diameter of 8.1 mm. If the rope stretches 4.2 cm, what is the mass of the climber?

*asked on August 3, 2019* -
## physics

A concave mirror with a radius of curvature of 0.61 m is illuminated by a candle located on the symmetry axis 2.61 m from the mirror. Where is the image of the candle? Answer in units of m.

*asked on November 20, 2013* -
## physics

A 9.1 g ball is hit into a 98 g block of clay at rest on a level surface. After impact, the block slides 8.0 m before coming to rest. If the coefficient of friction is 0.60, determine the speed of the ball before impact.

*asked on June 22, 2012* -
## math

Suppose you put $2000 in a savings account at an APR of 8% compounded quarterly. Fill in the table below. (Calculate the interest and compound it each quarter rather than using the compound interest formula. Round your answers to the nearest cent.) Quarter

*asked on October 24, 2017* -
## physics

A balloon carrying a basket is descending at a constant velocity of 20.0 m/s. A person in the basket throws a stone with an initial velocity of 15.0 m/s horizontally perpendicular to the path of the descending balloon, and 4.00s later this person sees the

*asked on February 9, 2008* -
## science

How are biology as a science and the environment related?

*asked on June 25, 2019* -
## Elementary Statistics

1) Construct a confidence interval of the population proportion at the given level of confidence. x=60,n=300, 99% confidence. The 99% confidence interval is (_,_) 2) A researcher wishes to estimate the proportion of adults who have high-speed internet

*asked on June 6, 2012* -
## physics

It is reasonable to assume that the bulk modulus of blood is about the same as that of water (2.20 GPa). As one goes deeper and deeper in the ocean, the pressure increases by 1.0*10^4 Pa for every meter below the surface. If a diver goes down 33.0 m (a bit

*asked on April 13, 2008* -
## Physics

You shoot an arrow into the air. 2.oo seconds later the arrow has gone straight upward to a height of 30 meters above its launch point. (a) What was the arrow's initial speed? (b) How long did it take for the arrow to first reach a height of 15 meters

*asked on October 1, 2011* -
## Physics

A 155 g aluminum cylinder is removed from a liquid nitrogen bath, where it has been cooled to -196 degrees c. The cylinder is immediately placed in a insulated cup containing 80g of water at 15 degrees c. What is the equilibrium temperature of this system?

*asked on August 4, 2019* -
## Chem

Calculate the enthalpy change in the reaction of H2 with F2 to produce HF. The H–H and F–F bond energies are 436 and 155 kJ/mol, respectively, and the H–F bond energy is 567 kJ/mol H2 (g) + F2 (g) --> 2HF (g)

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

A child pedals a tricycle, giving the driving wheel an angular speed of w=.875 rev/s. If the radius of the wheel is r=0.260 m, what is the child's linear speed, v?

*asked on June 30, 2019* -
## Health

a person can become dehydrated when wearing heavy clothing during aerobic exercise in warm weather true** false

*asked on May 24, 2016* -
## HUMAN DEVELOPMENT

The Seattle longitudinal study of cognitive development discovered that, among older people,

*asked on April 14, 2016* -
## Chemistry

If 18.8mL of 0.800M HCL solution are needed to neutralize 5.00mL of a household ammonia solution, what is the molar concentration of the ammonia? How do I solve this? Thank you.

*asked on September 29, 2010* -
## chemistry

0.24 grams of benzene (C6H6) is dissolved into 4.9 grams of melted biphenyl. The freezing point of the mixture was determined to be 4.4 degrees below the freezing point of pure biphenyl. Based on these results, what is the Kf of biphenyl? (Use the standard

*asked on November 13, 2012* -
## Chemistry

1. Calculate the pH of a buffer solution that contains 0.32 M benzoic acid (C6H5CO2H) and 0.17 M sodium benzoate (C6H5COONa). [Ka = 6.5 × 10-5 for benzoic acid] Round your answer to two places past the decimal. 2. A solution is prepared by mixing 470 mL

*asked on April 8, 2013* -
## Physics

A 210 g air-track glider is attached to a spring. The glider is pushed in 12.0 cm against the spring, then released. A student with a stopwatch finds that 13 oscillations take 16.0 s. Find the spring constant k.

*asked on January 21, 2011* -
## chemistry

Benzene has a heat of vaporization of 30.72kJ/mol and a normal boiling point of 80.1 degrees C. At what temperature does benzene boil when the external pressure is 470 torr?

*asked on September 7, 2008* -
## Chemistry

Calculate the number of carbon atoms in 0.75 L of acetone (CH3COCH3). (density=1.3g/mL and boiling point=48.5 degrees)

*asked on October 22, 2012* -
## Trig

Two ships leave a harbor at the same time. One ship travels on a bearing S11 degrees W at 12 mph. The second ship travels on a bearing N75 degrees E at 9 mph. How far apart will the ships be after 3 hours?

*asked on June 29, 2018* -
## organic chemistry isomers

which of the following molecules has a conformational isomer? CHCH CH2CH2 CH3CH2CH2CH3 CH2CCCH2 I think its either 2 or 4 but leaning towards 4. I just need help being more confident in my answer.

*asked on April 26, 2013* -
## Math( help please ! )

The profit p(x) of a cosmetics company , in thousands of dollars . is given by p(x) =-5t^2=400x-2550, where x is the amount spent on advertising in thousands of dollars a) determine the maximum profit the company can make b) dtermine the amount spent on

*asked on October 17, 2011* -
## Chemistry

How many grams of CaCl2 are needed to prepare 25.0 mL of .500 M solution? and What volume of 12.00 M HCL is needed to prepare 150.0 mL of .500 M HCL?

*asked on April 17, 2017* -
## Physics

Suppose you must remove an average of 3.4 X 10 ^8 J of thermal energy per day to keep your house cool during the summer. If you upgrade from an old air conditioner with a COP of 2 to a new one with a COP of 6, by how many joules is the required mechanical

*asked on August 4, 2019* -
## physics

In a rescue, the 64.0 kg police officer is suspended by two cables,the cable on the left made a 35 degree angle, the rope on the right made a 48 degree angle. What is the tension in the left cable? Find the tension in the right cable.

*asked on February 27, 2008* -
## Algebra 2(check pt 4)

1)Cramer's Rule is used to solve the system of equations:3m-5n=12,4m+7n=-5 Which determinant represents the numerator for n? answer=[12 -5] [-5 7] 2)Cramer's Rule is used to solve the system of equations:3x-y+2z=17,4x+2y-3z=10,and 2x+5y-9z=-6 Which

*asked on July 28, 2007* -
## Physics

An exercise machine indicates that you have worked off 2.1 calories in a minute and a half of running in place. What was your power output during this time? Give the answer in watts

*asked on August 3, 2019* -
## Statistics

It is estimated that heights of adult men are normally distributed with a mean of 70 inches and a standard deviation of 3.5. In one state, the law requires a person to be 68 inches or taller to become a fire fighter. (a) What proportion of adult men will

*asked on October 19, 2015* -
## Chemistry

According to the rules of golf, a golf ball cannot weigh more than 45.97 grams, and it must be at least 4.267 cm in diameter. The volume of a sphere is (4/3)πr3, where r is the radius. What is the density of a 45.67 g golf ball with a diameter of 4.267

*asked on February 9, 2019* -
## physics

A net force of 5.34 N acting for 4.23 s on a mass initial at rest, causes it to travel 4.75 m in a straight line. What is the mass?

*asked on October 2, 2014* -
## math (precalc)

Point S is 4 km west of point R, and point T is 4 km southwest of S. Find the bearing and distance from R to T. (If possible, show diagrams too, please! Thanks in advance.)

*asked on December 13, 2012* -
## physics

A woman with mass 50.0kg is standing on the rim of a large disk that is rotating at 0.500rev/s about an axis perpendicular to it through its center. The disk has a mass of 110kg and a radius of 4.00m. Calculate the magnitude of the total angular momentum

*asked on April 12, 2008* -
## physics

A tetherball leans against the smooth, frictionless post to which it is attached.The string is attached to the ball such that a line along the string passes through the center of the ball. The string is 1.20m long and the ball has a radius of 0.120mwith

*asked on February 27, 2008* -
## Health

_____are the result of an injury to a ligament DOMS Muscle sprain Muscle strain*** Overuse injury _______ Is the result of an injury to either a muscle or a tendon DOMS Muscle sprain*** Muscle strain Overuse injury

*asked on May 24, 2016* -
## Chemistry

Calculate the solubility of silver iodide in a 1.0 M sodium cyanide solution. Ksp = 8.5 x 10^-17 for AgI Kform = 2.5 x 10^5 for Ag(CN)2

*asked on April 7, 2010* -
## Chemistry

The reaction of 5.25 g of Carbon with excess O2 yields 10.2 g of CO2. What is the percent yield of this reaction?

*asked on February 20, 2019* -
## biotech

how would you prepare 300 ml of a 10% CaCl2 solution (w/w)?

*asked on November 29, 2011* -
## Chemistry

1. Calculate the pH of a buffer solution that contains 0.32 M benzoic acid (C6H5CO2H) and 0.17 M sodium benzoate (C6H5COONa). [Ka = 6.5 × 10-5 for benzoic acid] Round your answer to two places past the decimal. 2. A solution is prepared by mixing 470 mL

*asked on April 8, 2013* -
## chemistry

a liter of a solution saturated at 25C with CaC2O4 is evaporated to dryness giving a 0.0061 gm residue of CaC2O4. Calculate the concentrations of the ions, and the molar solubility and the solubility product constant for this salt at 25C. Show the balanced

*asked on June 10, 2012* -
## Math

The laurelwood pta is presenting it's 5th annual talent show and Kate is collected tickets at the door the gym is filled with 215 students and adults. Students tickets are .50 and adults tickets are 2.00. If Kate collected 250.00. How many adults and how

*asked on February 18, 2016* -
## chemistry

how would you prepare 300 ml of a 10% CaCl2 solution (w/w)?

*asked on November 29, 2011* -
## physics

A shiny metallic Christmas ball ornament 5.10 cm in diameter is used as a mirror. What is the mirror's focal length? please answer in cm. thanks.

*asked on May 7, 2011* -
## Physics

An object of mass 50 g floats in a liquid of density 2.5 g/ml. When the object is placed in a liquid of density 2.0 g/ml, it sinks to the bottom of the container. What is the force that the object exerts on the bottom of the container? [g = 10m/s^2 =

*asked on April 12, 2014* -
## math

One of the world's fastest roller coasters is located in a theme park in Valencia, California. Riders go from 0 to 100 miles per hour in 7 seconds. Find the acceleration of the roller coaster during this time interval in miles per second squared. Math -

*asked on September 27, 2010* -
## physics

A softball player hits the ball and starts running towards first base. Draw a motion diagram, using the particle model, showing her position and her average velocity vectors for the first few seconds of her run.

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

Relative to the ground, a car has a velocity of 14.8 m/s, directed due north. Relative to this car, a truck has a velocity of 24.0 m/s, directed 52.0° north of east. What is the magnitude of the truck's velocity relative to the ground?

*asked on January 26, 2012* -
## Physics please help!!

A cart of mass M1 = 5.00 kg and initial speed = 3.00 m/s collides head on with a second cart of mass M2 = 3.00 kg at rest. Assuming that the collision is elastic, find the speed of M2 after the collision. I have tried the answer 5.0 m/s however it says it

*asked on March 23, 2013* -
## Chemistry

A bottle of wine contains 11.4% ethanol by volume. The density of ethanol (C2H5OH) is 0.789 g/cm3. Calculate the concentration of ethanol in wine in terms of mass percent and molality.

*asked on September 23, 2012*