# Jackie

Most popular questions and responses by Jackie-
## physics

Two people, one twice as massive as the other, try to play tug of war on a nearly frictionless, level, icy surface. When they begin to tug, they are 12 m apart. They tug by pulling the rope hand over hand, until their hands meet along the rope. How far

*asked on December 8, 2014* -
## math

At a certain time of day, a pole, 5 meters tall, casts a 3 meter shadow. The shadow of the building beside the pole is 18 meters long. How tall is the building? How long will the shadow of a 45 meter building be?

*asked on March 22, 2016* -
## math

A culture of bacteria grows exponentially. It doubles in size every 16 hours. How long will it take to triple from its original size?

*asked on January 25, 2013* -
## Math

A deck from a card game is made up of about 108 cards. Twenty-five of them are red, yellow, blue, and green, and eight are wild cards. Each player is randomly dealt a seven-card hand. Write the final answer as a decimal rounded to six decimal places. 1.)

*asked on April 28, 2015* -
## Math

The hourly operating cost of an airplane, which seats up to 405 passengers, is estimated to be $5,500. If an airline charges each passenger a fare of $100 per hour of flight, find the hourly profit P it earns operating the airplane as a function of the

*asked on February 9, 2012* -
## AP physics

Vector A has a magnitude of 8.00 units and makes an angle of 45.0° with the positive x-axis. Vector B also has a magnitude of 8.00 units and is directed along the negative x-axis. Using graphical methods, find (a) the vector sum A + B and (b) the vector

*asked on August 23, 2009* -
## chemistry

Consider a solution made by mixing 500.0 mL of 0.04182 M Na2HAsO4 with 500.0 mL of 0.03645 M NaOH. Complete the mass balance expressions below for Na and arsenate species in the final solution. There are 4 arsenate species, but I only got three of them. I

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

Suppose BD−→− bisects ∠ABC. If m∠ABD=12x+24 and m∠DBC=20x+16, what is m∠ABC?

*asked on October 9, 2015* -
## American Government

Name the two factors that give federal courts jurisdiction over a case. Give an example of each.

*asked on January 3, 2017* -
## Calculus AP

i wanna KNOW IF im DOING RIGHT. Evaluate the difference quotient for the given function. Simplify your answer. f(x)=x+3/x+1, [f(x)-f(1)]/(x-1) simplify my answer: [(x+3)/(x+1) - (1+3)/(1+1)]/(x-1) = [x+3/x+1 - 4/2] / (x-1) = [2(x+3)-4(x+1)/2(x+1)] / (x-1)

*asked on June 4, 2012* -
## statistics

A physical fitness association is including the mile run in its secondary-school fitness test. The time for this event for boys in secondary school is known to possess a normal distribution with a mean of 440 seconds and a standard deviation of 60 seconds.

*asked on March 1, 2011* -
## math

assume the substance has a half-life of 11 years and the initial amount is 126 grams.How long will it be until only 15 % remains?

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

Ignoring activities, determine the molar solubility of copper (I) azide (CuN3) in a solution with a pH of 10.83. Ksp (CuN3) = 4.9 × 10–9; Ka (HN3) = 2.2 × 10–5.

*asked on March 21, 2013* -
## Chemistry please help :)

A 1.10 sample of dry ice is added to a 745 mL flask containing nitrogen gas at a temperature of 25.0 degrees C and a pressure of 735 mm Hg . The dry ice is allowed to sublime (convert from solid to gas) and the mixture is allowed to return to 25.0 degrees

*asked on October 24, 2011* -
## prealgebra

A barrel shaped like a cylinder is laid on its side and rolled up a ramp. The barrel has a circular base that is 0.9m in diameter. If the barrel turns 37 times in being rolled up the ramp, how long is the ramp? Use the value 3.14 for π . Round your answer

*asked on November 8, 2015* -
## Chemistry:Important!!!!!!!

20.00 mL of a H2SO4 solution with an unknown concentration was titrated to a phenolphthalein endpoint with 39.13 mL of a 0.1061 M NaOH solution. What is the concentration of the H2SO4 solution?

*asked on March 3, 2014* -
## math

ted Williams made deposits of 500.00 at the end of each year for eight years. the rat is 8% compounded annually. calculate the value of ted's annuity at the end of eight years

*asked on September 23, 2016* -
## DE Science

I am thinking A. A scientist claims plants and animals that exhibit reproductive cycles based on the changing seasons are highly affected by climate change. What is the correct justification of the scientist's claims? A) Climate change can cause a timing

*asked on November 14, 2013* -
## physics

A novice golfer on the green takes three strokes to sink the ball. The successive displacements of the ball are d1 = 3.98 m to the north, d2 = 2.01 m northeast, and d3 = 1.12 m at 30.0° west of south (see the figure). Starting at the same initial point,

*asked on September 26, 2013* -
## Math

assume the substance has a half-life of 11 years and the initial amount is 126 grams. How much remains at the end of 8 years?

*asked on January 25, 2013* -
## Chemistry

Consider this equilibrium process at 686°C. CO2(g) + H2(g) CO(g) + H2O(g) The equilibrium concentrations of the reacting species are [CO] = 0.050 M, [H2] = 0.045 M, [CO2] = 0.086 M, and [H2O] = 0.040 M. (a) Calculate Kc for the reaction at 686°C. (b) If

*asked on February 23, 2013* -
## math

At the amusement park, you decide to ride the Ferris wheel, which has a maxmum height of 80 meters and a diameter of 40 meters. It takes the wheel seven minutes to make one revolution. If you start your ride at the midline and the ferris wheel rotates

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

The floor of a rectangular room will be tiled with square tiles that measure 3 inches on each side. The room is 109 inches long and 103 inches wide. How many tiles, including parts of tiles, are needed to complete the job? A. 1,248 tiles B. 1,247 tiles C.

*asked on November 11, 2015* -
## quantitative chemistry

Consider a solution made by mixing 500.0 mL of 0.04182 M Na2HAsO4 with 500.0 mL of 0.03645 M NaOH. Complete the mass balance expressions below for Na and arsenate species in the final solution. There are 4 arsenate species, but I only got three of them. I

*asked on March 22, 2013* -
## english

John was late to dinner and I was late to the movies. simple complex compound compound-complex

*asked on January 5, 2015* -
## Chemistry

In 6.20 h a 100 g sample of ag 112 decays to 25 grams. what is the half life of ag 112. I think the answer is 3.10 but I'm not sure. Thanks in advance =)

*asked on June 15, 2011* -
## physics help!

The earth attracts a large ﬂying bug toward its center with a force of 0.10 Newtons. With what force does the bug attract the earth itself? 1. 1.0 N 2. 0.10 N 3. Trillions of Newtons 4. 10 N 5. We need the mass of the bug. 6. Zero; the earth attracts the

*asked on December 8, 2014* -
## math

a) 1150 dollars invested at 9% annual interest rate (compounded yearly) or b) 1475 invested at 6% annual interest (compounded yearly) after When would the two investments have equal value?

*asked on January 25, 2013* -
## trig

A bird at the top of a tree looks down at a field mouse with an angle of depression of 65 degrees. If the field mouse is 30 meters from the base of the tree, find the distance from which the field mouse to the bird's eyes. Round the answer to the nearest

*asked on July 22, 2013* -
## math

At the amusement park, you decide to ride the Ferris wheel, which has a maximum height of 50 meters and a diameter of 35 meters. It takes the wheel three minutes to make one revolution. If you start your ride at the midline and the ferris wheel rotates

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

(a) One of the moons of Jupiter, named Io, has an orbital radius of 4.22 108 m and a period of 1.77 days. Assuming the orbit is circular, calculate the mass of Jupiter. (b) The largest moon of Jupiter, named Ganymede, has an orbital radius of 1.07 109 m

*asked on October 22, 2013* -
## eng9

The profile of an earthquake survivor would most likely be included in (1 point) a feature article. an editorial article. a hard news article. a letter to the editor.

*asked on January 2, 2015* -
## Physics

1) Seagulls are often observed dropping clams and other shellfish from a height to the rocks below, as a mean of opening the shells. If a seagull drops a shell from rest at a height of 14 m, how fast is the shell moving when it hits the rocks?

*asked on October 2, 2017* -
## Chemistry

Consider the reaction: 3Ba(s)+N2(g)--->Ba3N2(s) 1)How many moles of barium metal react to produce 0.190 mol of barium nitride? 2)How many moles of nitrogen gas react?

*asked on December 14, 2011* -
## Physics

A novice golfer on the green takes three strokes to sink the ball. The successive displacements of the ball are d1 = 3.98 m to the north, d2 = 2.01 m northeast, and d3 = 1.12 m at 30.0° west of south (see the figure). Starting at the same initial point,

*asked on September 25, 2013* -
## history

Which of the following statements about the Grange and Farmers' Alliance movements is most accurate?

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

A reduced fat cookie contains 9g of fat per sereving. In order for food to be termed' reduced fat' it must have at least 25% less fat than the regular item. What can you conclude about how much fat is in a serving of the regular cookie? How much fat does a

*asked on May 20, 2011* -
## Physics

A block is at rest on an inclined plane. 63 kg µs = 0.47 èc Find the critical angle, èc, at which the block just begins to slide. Answer in units of ◦

*asked on December 7, 2014* -
## Statistics

Suppose x is a uniform random variable with c = 40 and d = 50. Find the probability that a randomly selected observation exceeds 46

*asked on March 3, 2011* -
## Math

Six sprinters have qualified for the finals in the 100-meter dash at the NCAA national track meet. In how many ways can the sprinters come in first, second, and third? (Let's assume there are no tires).

*asked on April 23, 2015* -
## Math

The hourly operating cost of an airplane, which seats up to 405 passengers, is estimated to be $5,500. If an airline charges each passenger a fare of $100 per hour of flight, find the hourly profit P it earns operating the airplane as a function of the

*asked on February 9, 2012* -
## Precal

Use a calculator to evaluate the expression. arcsin 0.45 arctan 15 arcsin(-0.125) arccos(-1/3)

*asked on March 30, 2011* -
## algebra with pizzzaz worksheet

does anyone know why do girls like guys who wear shirts with eight buttons? I have tried all of the problems two times each and still cannot make any sense of it. thanks!

*asked on February 3, 2009* -
## chemistry

Determine the molar solubility (S) of Zn(CN)2 in a solution with a pH = 4.91. Ksp (Zn(CN)2) = 3.0 × 10-16; Ka (HCN) = 6.2 × 10-10.

*asked on March 21, 2013* -
## Calculus help!

A ball is shot into the air from a bridge, and its height, y, in feet, above the ground t seconds after it is thrown is given by y=f(t) = −16t2 + 55t + 33. What is the average velocity of the ball during the first second? Round your answer to two decimal

*asked on February 6, 2013* -
## math

An innovative rural public health program is reducing infant mortality in a certain West African country. Pretend the program in Senegal has been reducing infant mortality at a rate 8.1 % per year. How long will it take for infant mortality to be reduced

*asked on January 25, 2013* -
## Physics

The acceleration of gravity is 9.8 m/s^2 . What is the magnitude of the total force on a(n) 72 kg driver by the dragster he operates as it accelerates horizontally along a straight line from rest to 61 m/s in 7.8 s? Answer in units of kN

*asked on November 30, 2014* -
## Geometry

Guy wires 80 feet long support a 65 foot tall telephone pole. To the nearest degree, what angle will the wires make with the ground?

*asked on March 5, 2012* -
## Science: Chemistry - Enthalpy

The enthalpy change in the combustion of the hydrocarbon octane is delta H = -5.48 x 10^3 kJ/mol C8H18(l). How much heat, in kilojoules, is liberated per gallon of octane burned? (Density of octane = 0.703 g/mL; 1 gal = 3.785 L.)

*asked on June 8, 2011* -
## programming

how do I write a pseudocode to find and display the largest list of positive numbers entered by the user. The user should indicate that he/she has finished entering numbers by enter a

*asked on August 28, 2011* -
## business math

If the interest rate is 3% and a total of $4,370.91 will be paid to you at the end of 3 year, what is the present value of that sum.

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

The speed of a projectile when it reaches its maximum height is 0.46 times its speed when it is at half its maximum height. What is the initial projection angle of the projectile?

*asked on October 18, 2009* -
## Physics

A brass rod 50.0 cm long expands 0.0734 cm when heated. Find the temperature change. Using the equation Change in temp=change in length/original length * coefficient of linear expansion for brass I am getting the following result: .0734 cm/(1.9x10^-5)(50

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

What is the pH and pOH of a solution that was made by adding 400mL of water to 350mL of 5.0x10^-3 M NaOH solution?

*asked on May 12, 2011* -
## Physics

A rock is dropped of the side of a bridge and hits the water below 4s later. a. What was the rock’s velocity when it hit the water? b. What was the rock’s average velocity as it fell? c. What is the height of the bridge above the water?

*asked on April 6, 2010* -
## Chemistry

How much heat (in kilojoules) is released on reaction of 4.10 g of Al? Reaction: 2Al(s) + 3Cl2(g)--->2AlCl3(s) Delta H= -1408.4 KJ

*asked on February 16, 2010* -
## chemistry

calculate the volume of Nitrogen gas generated at 21 degree celcius and 823 mmHg by the decomposition of 60.0 grams of sodium nitrate?

*asked on July 30, 2019* -
## physics

A jet of water squirts out horizontally from a hole near the bottom of the tank, as seen in the figure below. Assume that y = 1.19 m and x = 0.544 m. What is the speed of the water coming out of the hole? The hole has a diameter of 3.06 mm. What is the

*asked on March 5, 2012* -
## living environment

WHY IS THE DIFFERENCE BETWEEN PHOTOSYNTHESIS AND RESPIRATION DECSCRIBED AS A CYCLE? chemically, they are reverse processes: photosynthesis makes organic molecules and oxygen water from carbon dioxide and water. Respiration takes in oxygen and then "burns"

*asked on January 11, 2007* -
## Math

A certain country taxes the first $20,000 of an individual's income at a rate of 15%, and all income over $20,000 is taxed at 20%. a. Al makes $16,000. Betty makes $36,000. How much is each taxed? b. Write a piecewise function T that specifies the total

*asked on January 28, 2014* -
## Math 208

nico is saving money for his college education. He invests some money at 6%, and $1400 less that that amount at 5%. The investments produced a total of $172 interest in 1 yr. how much did he invest at each rate?

*asked on May 20, 2013* -
## Shirley English 3 rd grad

My daughter is working on Fragments and Correcting Run ON Sentences by SCV, SCS, and SS and she did not bring home her book. I have no idea what SCV and SCS and SS means! Can you please help?

*asked on November 10, 2011* -
## Calculus and Vectors

Show a graphical method of approximating the instantaneous rate of change at x = 3 for the function ƒ(x) = -x2 + 4x + 1 using secants. Show two graphical approximations. I had the same question but instructed to find it using a numerical method. No

*asked on July 15, 2019* -
## Calculus and Vectors

The magnetic force (Vector FM)on a particle in a magnetic field is found by Vector FM = Vector I × Vector B, Vector I is the charge multiplied by the velocity of a charged particle and Vector B the strength of the magnetic field, in Tesla (T). An electron

*asked on July 3, 2019* -
## History

A late-nineteenth-century Republican would have been more likely than a late-nineteenth-century Democrat to support? states' rights. reduced federal activity. reform legislation. lowered expenditures. help???

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

A kite is 32m above from the ground. The angle the kite string makes with the ground is 39°. How long is the kite string, to the nearest metre?

*asked on April 29, 2013* -
## Chemistry

A concentration cell consists of two Al/Al+3 electrodes. The electrolyte in compartment A is 0.05M Al(NO3)3 and in compartment B is 1.25 M Al(NO3)3. What is the voltage of the cell at 25 degrees Celcius?

*asked on July 20, 2012* -
## Pre-Algebra

Your baseball team has won 6 games and lost 4 games. If the team does not lose any more games, how many games must the team win to have a win: loss ratio of 2:1.

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

Analyse a work of art for example Jacob Lawrence "GOING HOME" to describe how he used both elements of art and principles of design to create a strong composition.

*asked on March 19, 2013* -
## economics

Assume that the equation for demand for bread at a small bakery is Qd = 60 - 10Pb + 3Y, where Qd is the quantity of bread demanded in loaves, Pb is the price of bread in dollars per loaf, and Y is the average income in the town in thousands of dollars.

*asked on September 18, 2012* -
## Personal Finance

Blake Williams has done some research and has discovered that economists believe interest rates will rise significantly over the next two years. Blake believes that this will lead to fewer homes being sold and fewer jobs in the banking and mortgage

*asked on April 21, 2015* -
## Algebra

Suppose that the annual interest rate on your checking account is 7.5 percent compounded continuously. In order to have $ 6300 in 7 years, how much should you deposit now? Assume, that the current balance is $ 0.

*asked on January 25, 2013* -
## chemistry... confusing!

a scuba diver breathing normal air descend to 100 m of depth, where the toal pressure is 11 atm. What is the partial pressure of oxygen that the diver experiences at this depth? I know that at 100m that a diver would have to breathe Heliox, meaning that

*asked on March 29, 2007* -
## Chemistry

If your body develops a charge of -19 (microcoulombs), how many excess electrons has it acquired? What is their collective mass? Please explain how to do this

*asked on September 7, 2011* -
## Algebra

Bit (a lot) of trouble solving this: The landing for the steps leading up to a county courthouse is shaped like a trapezoid. The area of the landing is 1500 square feet. The shorter base of the trapezoid is 15 feet longer than the height. The longer base

*asked on January 31, 2018* -
## life orientation

Factors of water that cause contemporary social? issues?

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

A rocket initially at rest accelerates at a rate of 80 m/s^2 for 0.74 min. What is its speed at the end of this time? Answer in units of m/s. Plz help and explain

*asked on October 4, 2016* -
## History

Which author's book on the link between naval might and international power influenced leading statesmen both in the United States and abroad? A) Chester Nimitz B) Oliver Hazard Perry C) Alfred Thayer Mahan D) Josiah Strong

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

A rocket is fired vertically with an upward acceleration of 30 m/s2. After 20 s, the engine shuts off and the rocket then continues rising (while in free-fall). The rocket eventually stops rising and then falls back to the ground. (a) What is the highest

*asked on September 13, 2010* -
## Physics

A ball of mass m(1) = 0.250 kg and initial v(1) = 5.00 m/s collides head-on with a ball of mass m(2) = 0.800 kg that is initially at rest. What are the velocities of the balls after the collision if they stick together?

*asked on January 11, 2013* -
## pre-cal

A small ferris wheel: A student is riding a 20-m-diameter ferris wheel that is making three revolutions per minute. If there are eight equally spaced seats on the Ferris wheel, then what is the length of the arc between two adjacent seats?

*asked on December 3, 2015* -
## Math/Trig

An airplane leaves an airport and flies due west 150 miles and then 170 miles in the direction 210°50'. Assuming the Earth is flat, how far is the plane from the airport at this time (to the nearest mile)

*asked on September 27, 2012* -
## Calculus and Vectors

Find the derivative of the following functions using [f(x+h) – f(x)]/h LIM h-0 ƒ(x) = x^2 + 5^x ƒ(x)= 1/2^x Show all your steps. I've been stuck on this question for a while,I understand how to do just the 5^x but not with the x^2 also. Any help

*asked on July 18, 2019* -
## Statistics

Consumption of alcoholic beverages by young women of drinking age has been increasing in the United Kingdom, the United States, and Europe (The Wall Street Journal, February 15, 2006). Data (annual consumption in liters) consistent with the findings

*asked on December 16, 2014* -
## Chem 130

When calcium carbonate is heated strongly, carbon dioxide gas is released. CaCO3(s) CaO(s) + CO2(g) What volume of CO2(g), measured at STP, is produced if 14.1 g of CaCO3(s) is heated?

*asked on May 5, 2014* -
## Math

Experience shows that a ski lodge will be full ( 156 guests) if there is a heavy snow fall in December, while only partially full ( 57 guests) with a light snow fall. What is the expected number of guests if the probability for a heavy snow fall is .40? If

*asked on January 18, 2010* -
## Geometry

One endpoint of a line segment is (8,-1). The point (5,-2) is one-third of the way from that endpoint to the other endpoint. Find the other endpoint.

*asked on October 1, 2011* -
## Calculus and Vectors

Determine the value of k so that the line with parametric equations x = 2 + 3t, y = -2 + 5t, z = kt is parallel to the plane with equation 4x + 3y – 3z -12 = 0. I got the cross product of (2,-2,0) and (4,3,-3) which is (6,6,14), but that's not adding up

*asked on July 9, 2019* -
## Chemistry

The quantity of antimony in a sample can be determined by an oxidation-reduction titration with an oxidizing agent. A 7.79-g sample of stibnite, an ore of antimony, is dissolved in hot, concentrated HCl(aq) and passed over a reducing agent so that all the

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

A figure skater is spinning with an initial angular speed of 6.9rad/s. She then pulls her arms in, reducing her moment of inertia to 0.38 times its original value. What is her angular speed after pulling in her arms?

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

How many grams of I2 are present in a solution if 39.85mL of 0.160M Na2S2O3 solution is needed to titrate the I2 Solution

*asked on March 14, 2014* -
## Precalculus

You have a total of 820 feet of fencing to enclose a large retangular larea and divide it into four smaller pens of the same dimensions. The fencing used to divide the large pen must be parallel to the same side of the large rectangle. Maximize the total

*asked on June 19, 2012* -
## Math

The annual precipitation for one city is normally distributed with a mean of 329 inches and a standard deviation of 2.6 inches. Find the probability that a randomly selected year will have more than 323.8 inches of rain. Express the probability as a

*asked on September 20, 2015* -
## geometry

Find the point that is one-fourth of the way from (2,4) to (10,8).

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

Chris eats 3 slices of a pizza that is cut into 8 equal slices. What percentage of the pizza does he eat?

*asked on March 1, 2011* -
## personal finance

Which of the following is a true statement? A. The dividends-earnings ratio is a key factor that serious investors use to evaluate stock investments. B. The price-earnings ratio for a corporation must be studied for one period only. C. The price-earnings

*asked on April 23, 2015* -
## HCA

a 700- to 1,050-word paper that includes the following: • Describe the principles of verbal and nonverbal communication. • Explain which three principles you think are critical for effective communication. • Include at least one personal experience

*asked on October 9, 2012* -
## algebra

Jeremy is building a deck for the community center. The deck is shaped as rectangle. The width of the deck is 29ft. The perimeter of the deck is to be at least 134ft. Write an inequality that represents all possible values of the length of the deck. Find

*asked on September 9, 2012* -
## math

A supplier provides parts to a manufacturing company that demands JIT deliveries. At the present time it takes 6 hours to make a round-trip between the supplier's warehouse and the customer, including loading, travel and unloading time. The lot size is 12

*asked on November 30, 2010* -
## chemistry

Does the application of heat to a substance always produce a chemical change? And give examples to support your answer.can someone help me?

*asked on May 3, 2010*