# Mack

Popular questions and responses by Mack-
## Chemistry

13.A student mixed 5.00 g (0.0594 mol) of solid cyclohexane, C6H12, (84.18 g mol–1) at its melting temperature of 6.6°C with 50.0 g (0.594 mol) of liquid cyclohexane at 50.0°C in an open yet insulated container. After thermal equilibrium was

*asked on February 20, 2019* -
## math help please check my answer

A roofer is standing on the roof of a house 60 ft above the ground. His truck is parked 25 ft from the house. What is the angle of depression from the roofer to his truck? Round to the nearest whole degree. 22° 23° 67° 68°

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

A positive integer n is defined as a "prime interlude" if n-1 and n+1 are both prime numbers. Which of the following is not a "prime interlude?" a.4 b.18 c.30 d.72 e.90 ( First of all; What is a "prime interlude??") I don't understand the question and

*asked on August 9, 2007* -
## Math

How do I solve this problem? There are 8 sections of seats in an auditorium. Each section contains at least 150 seats but not more than 200 seats. Which of the followin could be the number of seats in this auditorium? What are your choices? Multiply 150 x

*asked on May 20, 2007* -
## Physics

A spinning wheel is slowed down by a brake, giving it a constant angular acceleration of −4.60 rad/s2. During a 2.60-s time interval, the wheel rotates through 85.4 rad. What is the angular speed of the wheel at the end of the 2.60-s interval?

*asked on April 8, 2015* -
## science

Flight simulators are used to train new pilots because ____.

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

Ameter stick casts a shadow 1.4 m long at the same time a flagpole casts a shadow 7.7 m long. The triangle formed by the meterstick and its shadow is similar to the triangle formed by the flagpole and its shadow. How tall is the flagpole?

*asked on March 24, 2011* -
## Statistics

The mean serum cholesterol level in the population of males who do not develop heart disease is known to be 219 mg/100 ml. Suppose you perform a study to investigate whether the mean serum cholesterol levels in males who do develop heart disease is higher

*asked on December 6, 2010* -
## African American History

The Middle Passage What did the Explorer Bartholomeau Dias discover? Why was the mortality rate so high?

*asked on October 11, 2007* -
## physics

I need a plan to solve this problem and I'm stuck. Please help. A basketball laeaves a player's hands at a height of 2.10m above the floor. The basket is 2.60m above the floor. The player shoots the ball at a 38.5 degree angle. If the shot is made from a

*asked on September 25, 2007* -
## Health

What is a physician specializing in female reproductive system problems? Physician specializing in cancer? What is a Physician specializing in urinary problems? What is a Physician specializing in allergies? What is a Physician Specializing in nervous

*asked on September 12, 2007* -
## Math

The table shows some values for the function f. If f is a linear function, what is the value of a+b? a24 b36 c48 d72 eit cannot be determined from the information given. x f(x) 0 a 1 24 2 b The Answer is c48. How did they arrive at that answer????????? The

*asked on May 20, 2007* -
## Environmental Science

Many areas of the world that do not have adequate fresh water have become habitable because a.rainfall patterns have changed b.water management projects have diverted water to the areas c.icebergs have been towed in to provide fresh water d.people have

*asked on April 20, 2007* -
## Geomentry

What is the converse of the theorem statement: If a line divides two sides of a triangle proportionally, then it is parallel to the third side. see the other post.

*asked on April 3, 2007* -
## Geomentry

What is the converse of the theorem statement: If a line parallel to one side of a triangle intersects the other two sides, then it divides the two sides proportionally. If two sides of a triangle are divided in the same proportion, then the line

*asked on April 3, 2007* -
## Math

x y 1 1 2 4 3 9 4 16 Does the table represent x as DIRECTLY PROPORTIONAL to y? Why or why not? A) No, because the y-values are not increasing at a constant rate. B) Yes, because the x- and y-values are increasing proportionately. C) No, because the

*asked on March 2, 2020* -
## MATH

A TAXI CAB COST $1.25 FOR THE FIRST MILE AND $.25 FOR EACH ADDDITIONAL MILE. how many miles can be traveled in the taxi for $8.00? M= number of miles traveled.

*asked on January 31, 2016* -
## pre-calculus

two gears are connected by a belt. the large gear has a radius of 20cm while the small gear has a radius of 10cm. if a point on the small gear travels at 16 rpm (revolutions per minute), find the angular velocity of the large gear. Tip: first find the

*asked on August 10, 2015* -
## Math

How to plot (0,-2)

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

A circus performer walks on a tightrope 25 ft above the ground. The tightrope is supported by two beams and two support cables. If the distance between each beam and base of its support cable is 15 ft, what is the length of the support cable?

*asked on September 22, 2014* -
## Math

Each fence section has a post at each end. How many posts are needed to build a fence with 10 sections? Is it 8, 11, 10 or 9 posts ?? Please explain to really want to understand this!!

*asked on May 11, 2012* -
## Algebra 2

n is 2 given that it is even directions: let n be a randomly selected integer from 1 to 20 find the indicated probability

*asked on May 4, 2011* -
## economics

1. Use the following information to answer the questions below: Quantities Produced Prices CDs Tennis Racquets CDs Tennis Racquets Year 2004 100 200 20 110 Year 2005 120 210 22 120 a. Calculate real GDP using prices from 2004. By what percent did real GDP

*asked on August 10, 2010* -
## Math

Open Ended Electronic City pays its starting employees $8.50/hour. After 6 months, employees get a choice of how they would like to be paid. They can choose from one of the following plans: Plan A: Remain at $8.50/hr, working 40 hours a week. Plan B:

*asked on March 3, 2008* -
## African Amer. Study

What was the aim of the American Colonization Society?

*asked on January 29, 2008* -
## English 4

I need a summary of the story the "Ilead". I'm having trouble understanding the story.

*asked on October 11, 2007* -
## S.A.T Math

At Central Park Zoo,the ratio of sea lions to penguins is 4 to 11. If there are 84 more penguins than sea lions, how many sea lions are there? The answer book says: C is the answer. The correct answer should yield a ratio of sea lions to Penguins of 4 to

*asked on August 27, 2007* -
## Math

75 mg of salt is equivalent to how many grams of salt? They got 0.075. How did they arrive at that answer? A milogram (mg) is 1/1000 of a gram. In other words, each gram contains 1000 milograms. To convert from mg to grams, divide the mg by 1000. In this

*asked on June 26, 2007* -
## history

What vital right did the Spanish allow the Western farmers? Answer: It was that Spain allowed Americans to travel on the lower Mississippi to New Orleans and to ship their goods. "cORRECT right??" mmhmm Can you help me out with this one???? Did you ever

*asked on April 29, 2007* -
## history

What was the name of the sturdy vehicle used to trasport westward bound pioneers and their possessions? covered or "Calistoga" wagon. This type of wagon was also used... for carrying freight. http://en.wikipedia.org/wiki/Conestoga_wagon

*asked on April 27, 2007* -
## history

The precedent that Marbury v. Madison set was a lawsuit right? http://en.wikipedia.org/wiki/Marbury_v._Madison

*asked on April 27, 2007* -
## history

What are 5 ways that Jefferson and Republicans simplified Government? Which Republicans are you refering to? The Democratic-Republican Party of Jefferson or the Republican Party of Lincoln? Jefferson Jefferson

*asked on April 27, 2007* -
## history

can some one check my work? i can where is it It's the one with the one that says order the sequence. Hi! brie. My work is on the 2nd page. Count the BLACK dots next to everybody's name until you find the 35th dot. Check that work. You'll see it next to my

*asked on April 27, 2007* -
## Environmental Science

Could you please explain the distinction between eutrophication and artifical eutrophication sense eutrophication is the natural process by which a body of water gains an abundance of nutrients? One is natural and occured long before man's time. The other

*asked on April 20, 2007* -
## Environmental Science

Here is a sentence that says: In bodies of water polluted by phosphorus, algae can form large floating mats, called algal blooms. What substance causes an alfal bloom to form? (I don't understand the sentence) That's "algal bloom" See:

*asked on April 20, 2007* -
## Environmental Science

Which of the following is one way that a person can conserve water? a.Take a bath instead of a shower b.Wash laundry in small, partial loads c.use a low flow shower head to take short showers d.water the lawn daily and at nidday. I picked a. right? Because

*asked on April 20, 2007* -
## Environmental Science

What is the purpose of adding alum to water during the water treatment process? a.to filter and remove large organisms and trash b.to form flocs that bacteria and other impurities will cling to c.to prevent bacterial growth d.to remove unwanted gases I

*asked on April 20, 2007* -
## Environmental Science

The three major global uses of fresh water are a.manufacturing goods, wastewater disposal, and irrigation. b.drinking, bathing, and growing crops. c.drinking, manufacturing goods, and generating power d.residential,agricultural,and industrial uses. I

*asked on April 20, 2007* -
## Environmental Science

Most of the oil that pollutes the ocean comes from a.operating boats and personal watercraft b.spills from oil tankers c.runoff from cities and towns d.leaking underground storage facilities I picked d. That made sense to me. something that is leaking from

*asked on April 20, 2007* -
## history

What happens in the elections of 1824? Thank you for using the Jiskha Homework Help Forum. I would not say "what happens" but rather "what happened." Here are some links for you: 1. http://en.wikipedia.org/wiki/United_States_presidential_election,_1824 2.

*asked on March 25, 2007* -
## Science

I need help please. I'm really clueless of what the answer is. The theory of demographic transition is based on the idea that industrial development causes ________ and ___________ progress that affect population growth rates. [I really have no clue what's

*asked on March 19, 2007* -
## Science

will someone please answer my question!!!!!!!!!!!! I need finding the missing word. here's what I wrote but i'm not to sure it's the right answer. China has implemented a campaign to reduce birth rates that includes _________ rewards for single child

*asked on March 19, 2007* -
## Science

I need help finding the missing word heres what i wrote. But i'm not to sure this word goes with it. An adequate supply of fuelwood helps to prevent disease by allowing water to be boiled to ____________ it. [Protect???] sterilize

*asked on March 19, 2007* -
## Science

Accordind to the theory of demographic transition,why do birth rates fall during the third stage? Please check your assigned reading and post your answer. We'll be glad to help you when we see your thoughts about this subject. Premature births and

*asked on March 18, 2007* -
## Science

The theory of demographic transition is based on the idea that industrial development causes __________ and ___________ progress that affect population growth rates. Please check your assigned reading and post your answer. We'll be glad to help you when we

*asked on March 18, 2007* -
## Science

The study of human population patterns is called _________________. Thank you for using the Jiskha Homework Help Forum. Here is what the Online Dictionary says: Main Entry: de·mog·ra·phy Pronunciation: di-'mä-gr&-fE Function: noun Etymology: French

*asked on March 18, 2007* -
## Science

[I choose a.] Preserving entire ecosystems rather than individual species is a good conservation strategy because a.only endangered species will be saved b.developers will have greater access to land c.more than one species can be saved d.it will not be

*asked on March 18, 2007* -
## History

What is the theory of mercantilism?

*asked on December 2, 2019* -
## physics

A man can throw a ball a maximum horizontal distance of 142 m. The acceleration of gravity is 9.8 m/s 2 . How far can he throw the same ball vertically upward with the same initial speed? Answer in units of m.

*asked on October 14, 2019* -
## Physics

A 15kg box is resting on a hill forming an angle with the horizontal. The coefficient of static friction for the box on the surface is 0.45. Calculate the maximum angle of the incline before the box starts to move. Steps included would be great, I have the

*asked on June 20, 2018* -
## mathematics

The solution below corresponds to an inequality involving a quartic function. Write a possible quartic polynomial inequality that matches the solution. Prove that your inequality matches the solution. x < 4 and x > 7

*asked on January 7, 2018* -
## Physics

2 Dimensional Motion-Kinematics QS 1: An airplane wishes to travel 800 km northeast of a starting point. There is a wind blow towards the east at 100km/h. Assuming the maximum speed of the plane in still air is 500km/h, a: what course should the pilot

*asked on September 12, 2017* -
## Sociology

According to Parsons, evolutionary change occurs through a two step process involving A) the ideational and the sensate B) differentiation and integration C) core societies and peripheral societies D) industrialization and modernization

*asked on March 29, 2016* -
## algebra

jack can mop a ware house in ten hours. one day his friend Jimmy helped him and it only took 4.44 hours. How long would it take Jimmy to do it alone?

*asked on January 19, 2016* -
## CHEMISTRY

Using a 0.20 M phosphate buffer with a pH of 6.5, you add 0.72 mL of 0.46 M NaOH to 58 mL of the buffer. What is the new pH of the solution? (Enter your answer to three significant figures.) I don't even know where to begin!! I just need a set up of the

*asked on March 3, 2015* -
## physics

How much thrust is required to launch a 5 kg bottle rocket with an upward acceleration of 6.4 m/s2? I've gotten 32 because F=MA but I don't understand how to account for gravity. Please help!

*asked on December 30, 2014* -
## Social Studies

What did Clinton mean by "a dear bought victory, another such would have ruined us"

*asked on November 20, 2014* -
## Math

10 ÷ 4/5

*asked on November 20, 2014* -
## engineering science N4

A steel block is resting on a Flat plank 6m long ,and how high can one end of a plank be lifted For the block to start to move,if the coeficient of friction is 0.3

*asked on October 12, 2014* -
## Math

How do you solve (5,-1) -(2,-6) ________ (?,?)

*asked on October 1, 2014* -
## Math

A door frame that appears rectangular has height 80 in., width 32 in., and one diagonal that measures 86in. Is the door frame actually rectangular?

*asked on September 28, 2014* -
## math (fractions)

Three people share a sum of money. The first receives 2/7 and the second receives a 2/5 share of the money. What fracion does the third receive?

*asked on January 20, 2014* -
## Math

An object is projected vertically upward from the top of a building with an initial velocity of 144 ft/sec. Its distance s(t) in feet above the ground after t seconds is given by the function s(t) = −16t2 + 144t + 120. A) Find its maximum distance above

*asked on July 11, 2013* -
## AP US History

One of the ironies of World War I was that in a war 'to make the world safe for democracy,' the government attacked the civil liberties that make democracy possible.

*asked on April 24, 2013* -
## Probability

Roberto has 10 different colored sheets of paper and 3 different colored envelopes. How many different letters can he make consisting of one colored sheet of paper and one colored envelope??? Please explain!

*asked on May 11, 2012* -
## alg 1 college

can you guys please help me wwith a math problem, its asking to solve this equatoion, sqare root5x-4=3x-18. to fkire off first 5x-4= 3x-18 squared. foil thatand you are looking AT 9x squared -54x -54x+324/ add the -54 to 108x.then shoot the 5x to to the

*asked on March 20, 2012* -
## statistics

A company markets educational software products, and is ready to place three new products on the market. Past experience has shown that for this particular software, the chance of "success" is 80%. Assume that the probability of success is independent for

*asked on February 4, 2012* -
## Physics

A 90 kg mover climbs a ladder to a height of 8 m in 32 s. Find the power rating of the mover. I solved by using P= mgh/t and came up with 220.5 watts. Is this correct or am I suppose to use P=w/t and not use gravity in the equation?

*asked on December 5, 2011* -
## physics

A 90 kg mover climbs a ladder to a height of 8 m in 32 s. Find the power ratingof the mover. I solved by using P= mgh/t and came up with 220.5 watts. Is this correct or am I suppose to use P=w/t?

*asked on December 4, 2011* -
## physics

A 500g ball is dropped into a well that is 10m deep. A)What is the ball's potential energy before it is dropped? Take the bottom of the well to be at zero height. I solved by using PE=mgh and came up with 49J. B) What are the kinetic energy and potential

*asked on December 4, 2011* -
## Physics

A 500g ball is dropped into a well that is 10m deep. A)What is the ball's potential energy before it is dropped? Take the bottom of the well to be at zero height. I solved by using PE=mgh and came up with 49J. B) What are the kinetic energy and potential

*asked on December 4, 2011* -
## physics

A 160g stone, tied to a thread, swings in a horizontal circle with a 100 cm diameter. If the maximum tension the thread can withstand before snapping is 28n, find the A) Maximum speed of the stone. B) Acceleration of the stone at this speed. For A I used

*asked on November 22, 2011* -
## Physics

A 160g stone, tied to a thread, swings in a horizontal circle with a 100 cm diameter. if the maximum tension the thread can withstand before snapping is 28 N, find the A) Maximum speed of the stone B) Acceleration of the stone at this speed. I solved A

*asked on November 19, 2011* -
## physics

A ball weighing 1.78 N is shot through a launcher, achieving a speed ( from rest) of 41 m/s in 0.28 s. A) What is the mass of the ball? B) What is the acceleration of the ball as it moves through the launcher? C) What average force acted on the ball to

*asked on November 19, 2011* -
## physics

the centers of two 5000 kg blocks are separated by 1.13 m. What is the gravitational force between the two blocks? What must be the distance between the centers of the blocks if the gravitational force decreases 25 times?

*asked on November 19, 2011* -
## statistics

What SPECIFIC statistical test would be applied to these data collected to answer the following questions? What’s the average amount of pain Mr. Smith reported yesterday? Is there a significant difference in depression levels (using a scale of 0-60)

*asked on October 7, 2011* -
## physics

what is the momentum of a cart with a mass of 30 kg which is moving at rate of 54 km/hr?

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

A football is kicked stright up into the air it hits the ground in 4.6 sec later, what was the greatest height reached?

*asked on September 3, 2011* -
## chemistry

what products would be formed if glycerol were combusted? wright a balanced equation for the combuntion reaction of glycerol (C3,H8,O3).

*asked on June 16, 2011* -
## Trig

What is the vertical asymptote of y=tan(x-pi/3)?

*asked on April 28, 2011* -
## Trigonmetry

If an airplane is traveling at 750 mph bearing of S 65 W for 3 hours how far will the plane travel? And what bearing should they travel home?

*asked on April 28, 2011* -
## science

what is silica content of earths crust under the oceans?

*asked on October 20, 2008* -
## math

-2(18+19)8th x 19 +18 divided by 9 seventh power x 6

*asked on September 15, 2008* -
## MATH HELP!

HELP! I REALLY NEED HELP IN BASIC SKILLS MATH! Can you please find me a GOOD web site that will help me in random basic skills math?

*asked on May 7, 2008* -
## Physics

A runner weighs 560 N (about 130 lb), and 74% of this weight is water. (a) How many moles of water are in the runner's body? moles (b) How many water molecules (H2O) are there? molecules

*asked on April 19, 2008* -
## Math

Open Ended Nick is starting college in the fall. She has purchased a Star Phone card for $30.00for long didtance calls. The calls cost 10 cents per minute nation wide during the daytime, 6 a.m - 6 p.m and 5 cents per minute nationwide at night, 6 p.m-6a.m.

*asked on March 3, 2008* -
## Math

Open ended Need HELP PLEASE!!! Mr.Guy isfinishing his patio. The Patio is 14ft. by 4yds. -If each square tile is 2 by 2, how many will he need? -If the tile is 5 dollars each, but he gets every 5th one free, how much will it cost? -If tiles are also sold

*asked on March 3, 2008* -
## Math

To confuseing I need help. In honor of school spirit week, the student council decided to decorate lockers in the main lobby. The 9th graders officers stuck a decal of Smiley, the school mascot, on every third locker, starting with the third. The 10th

*asked on March 3, 2008* -
## American Sign Language

What is a asl classifier for President? What is a asl classifier for woman? What is a asl classifier for letter? What is a asl classifer for brother?

*asked on February 18, 2008* -
## English 4

what are the steps in writing a good essay?

*asked on February 9, 2008* -
## African American History

I needed to put these in chronological order: David Walker's appeal, American Colonization Society formed, Paul Cuffe leads African American to Sierra Leone. I wrote American Colonization Society formed for 1, Davis Walker's appeal for 2, and Paul Cuffe

*asked on January 29, 2008* -
## African Amer. Study

Who lead the most forceful strategy in order to bring an end to slavery?

*asked on January 29, 2008* -
## African Amer. Study

What was the name of the abolitionist paper of William Lloyd Garrison?

*asked on January 29, 2008* -
## African Amer. Study

Who was the 1st American woman to address male audience in public?

*asked on January 29, 2008* -
## African Amer. Study

Who was involved in the Baltimore Alliance?

*asked on January 29, 2008* -
## African Amer. Study

Where and When was the 1st female anti- slavery established?

*asked on January 29, 2008* -
## African Amer. Study

What was the Baltimore Alliance?

*asked on January 29, 2008* -
## African Amer. Study

What's another name for Jack Pritchard?

*asked on January 29, 2008* -
## African Amer. Study

Who published Freedom's Journal?

*asked on January 29, 2008* -
## African Amer. Study

Who was the first women to address male audience in Public?

*asked on January 29, 2008*