Thursday

August 25, 2016
Total # Posts: 3,444

**physics**

Two friends, Al and Jo, have a combined mass of 171 kg. At an ice skating rink they stand close together on skates, at rest and facing each other, with a compressed spring between them. The spring is kept from pushing them apart, because they are holding each other. When they ...
*January 25, 2012*

**Math**

A model rocket is shot straight up from the roof of a school. The height at any time t is approximated by the model h=-t^2+3t+28, where h is the height in meters and t is the time in seconds. When does the rocket hit the ground?
*January 24, 2012*

**physics**

A 0.579 kg basketball is dropped out of a window that is 6.22 m above the ground. The ball is caught by a person whose hands are 1.31 m above the ground. How much work is done on the ball by its weight?
*January 22, 2012*

**trig**

Please explain to me how to get this -- what quadrant tan theta < 0, sin theta < 0 is in.
*January 21, 2012*

**Trig**

what quadrant is this in and please explain... sin theta < 0, cos theta > 0
*January 21, 2012*

**trig**

5pi/7 what quadrant is it in???
*January 21, 2012*

**physics**

A 49.4 kg swimmer is standing on a stationary 214 kg floating raft. The swimmer then runs off the raft horizontally with a velocity of +3.60 m/s relative to the shore. Calculate the magnitude of the recoil velocity that the raft would have if there were no resistance due to ...
*January 19, 2012*

**physics**

A baseball (m = 149 g) approaches a bat horizontally at a speed of 39.8 m/s (89.0 mph) and is hit straight back at a speed of 45.8 m/s (102 mph). If the ball is in contact with the bat for a time of 1.27 ms, what is the average force exerted on the ball by the bat? Neglect the...
*January 19, 2012*

**languag arts**

In the sentence, "Sylvia looks good in her mermaid costume" why is good the correct word used as an adjective, as opposed to using well as an adverb. Isn't "good" describing how Sylvia looks?
*January 16, 2012*

**physics**

The three-toed sloth is the slowest moving land mammal. On the ground, the sloth moves at an average speed of 0.0330 m/s, considerably slower than the giant tortoise, which walks at 0.0800 m/s. After 10.2 minutes of walking, how much further would the tortoise have gone ...
*January 15, 2012*

**physics**

A woman on a bridge 77.4 m high sees a raft floating at a constant speed on the river below. She drops a stone from rest in an attempt to hit the raft. The stone is released when the raft has 7.07 m more to travel before passing under the bridge. The stone hits the water 4.18 ...
*January 15, 2012*

**physics**

An astronaut on a distant planet wants to determine its acceleration due to gravity. The astronaut throws a rock straight up with a velocity of 13.5 m/s and measures a time of 21.8 s before the rock returns to his hand. What is the acceleration due to gravity on this planet? (...
*January 15, 2012*

**physics**

Jordan tosses a ball upwards with an initial velocity of 14.0 m/s. What is the displacement in meters of the ball during the first 2.5 seconds after she threw it? (don't include units in the answer, use 10.0 m/s2 for g and use the upward direction as positive)
*January 11, 2012*

**physics**

Daniel tosses a ball upwards with an initial velocity of 10.0 m/s. In meters/second, what is the velocity of the ball 1.3 seconds after he threw it? (use 10.0 m/s2 for g and use the upward direction as positive)
*January 11, 2012*

**Physics**

Daniel tosses a ball upwards with an initial velocity of 10.0 m/s. In meters per second, what is the velocity of the ball 1.3 seconds after he threw it? (use 10.0 m/s2 for g and use the upward direction as positive)
*January 11, 2012*

**Physics**

A drag racer starts her car from rest and accelerates at 9.0 m/s2for the entire distance of 60.0 m. What is its speed at the end of the run? Answer in units of m/s.
*January 11, 2012*

**physics**

A drag racer starts her car from rest and accelerates at 9.0 m/s2for the entire distance of 105.0 m. What is its speed at the end of the run? Answer in units of m/s.
*January 11, 2012*

**solid geometry**

what are the dimensions of a gallon can of uniform square cross section whose height is twice the length of an edge of its base?
*January 10, 2012*

**statistics**

Records show that deaths occur at the rate of 0.1 per day among patients residing in a large nursing home. If someone dies today, what are the chances that a week or more will elapse before another death occurs? The answer is 0.50 and the problem is in the Poisson section but ...
*December 11, 2011*

**physics**

A merry-go-round in a playground has a mass of 200 kg and radius of 1.50 m. You apply a force F = 23 N tangentially to the edge of the merry-go-round for a time of 6.5 s. The moment of inertia of the merry-go-round is 1/2(mR2). What is the angular acceleration of the merry-go-...
*December 9, 2011*

**HELLLLP Math**

nm figured it out
*December 8, 2011*

**HELLLLP Math**

A steel tube, which is closed at both ends, is filled with air. The air in the tube is vibrating at a frequency of 200·Hz. Use 340·m/s for the speed of sound in air. If the 200·Hz vibration respresents the fundamental standing wave for the tube, how long ...
*December 8, 2011*

**math**

A woman is sitting in a boat at anchor on a lake. Her boat bobs up and down once every 2.0·s. She notices that when the front of her 3.0·m long boat is at one wave crest, a second crest is at the middle of her boat, and a third is at the end. What is the ...
*December 8, 2011*

**physics**

A steel tube, which is closed at both ends, is filled with air. The air in the tube is vibrating at a frequency of 200·Hz. Use 340·m/s for the speed of sound in air. (a) What is the wavelength of the sound waves in the tube? _____ m. (b) If the 200·Hz ...
*December 8, 2011*

**Pensacola State**

The solubility of NH3 in H20 is 518 g/L at a partial pressure of 760.0 torr. 1. Calculate the value of the Henry's Law constant for NH3. 2. calculate the solubility of NH3 in H2O at a partial pressure of 225.0 torr.
*December 6, 2011*

**statistics**

what happens to the width of our confidence interval for mu if we increase the sample size but keep the confidence level the same ? a. it increases b. it stays the same c. it decreases d. it depends on the sample mean and standard deviation
*December 6, 2011*

**statistics**

according to the energy information administration (officially energy statics from the US Government) the mean price for one gallon of unleaded regular gas in the US cities for the year 2007 was 2.80 A random sample of 30 pumps in georgia yielded and average price of 284 per ...
*December 6, 2011*

**statistics**

a recent study suggests that the mean maximum temperature for the month of december in nyc is different from 41 degrees F. provide the null and alternative hypotheses for this test.
*December 6, 2011*

**statistics**

we are interested in testing at level of significance alpha =10 whether the population mean is different than 15. a random sample of size 25 is taken with a mean of 13.9. assume standard deviation is 2 and normally distributed population. find the values for zcrit
*December 6, 2011*

**statistics**

Assume that body temperatures of healthy adults are normally distributed with a mean of 98.2 degrees F and a standard deviation of .62 degrees F. suppose we take a sample of eight healthy adults. what is the probability that their mean body temperature will be greater than 98.4
*December 6, 2011*

**statistics**

Assume that body temperatures of healthy adults are normally distributed with a mean of 98.2 degrees F and a standard deviation of .62 degrees F. suppose we take a sample of eight healthy adults. what is the probability that their mean body temperature will be greater than 98.4
*December 6, 2011*

**pre-algebra**

We need more info. What is the full problem?
*December 6, 2011*

**geometry**

(1)r y-axis °r x-axis (2)T 2,-3 °y=x (3)r y=-x °D 3 (4)R o °R o HELP!!
*December 4, 2011*

**geometry**

Which composition would produce an image triangle whose area is not equal to the area of the original triangle?
*December 4, 2011*

**math**

Suppose that fifteen observations are chosen at random from the pdf f_Y(y) = 3y^2, 0<=y<=1. Let X denote the number that lie in the interval (1/2, 1). Find E(X). E(X) is the expected value or average.
*November 29, 2011*

**finance**

I am thinking that the answer is c because if the company is operating above its breakeven point and the fixed costs are constant then the profits should increase by more than 15% since they aren't receiving any additional costs.
*November 27, 2011*

**finance**

If a company has fixed costs and is operating above the breakeven point, when sales increase by 15%, profits will: a. increase by less than 15% b. increase by 15% c. increase by more than 15% d. decrease by less than 15%
*November 27, 2011*

**math**

two integers have sum of 23 and a difference of 7. which of the following is also true about these integers? A they have a product of 161. B they have a qoutient 4. C they have a product of 120. D they have a qoutient of 2.
*November 23, 2011*

**american history**

Yo chill anonymous :(
*November 19, 2011*

**physics**

A .1kg mass is located on the line between a 5kg mass and a 10kg mass. It is 4m to the right of the 5kg mass and 6m go the left of the 10kg mass. What is the magnitude and direction of the net force on the .1kg mass?
*November 17, 2011*

**math**

an amount invested in an account that offers 5% interest which is compounded annually. how long will it take for this amount to double?
*November 17, 2011*

**physics**

a helicopter has a speed relative to the air of 76km/h northeast. The speed of the wind relative to the ground is 28km/h south. 2 hours after leaving the ground, what is the displacement of the helicopter relative to the ground?
*November 11, 2011*

**math**

a) 7.49 miles b) 0.12 miles per minute
*November 10, 2011*

**Biology**

How can you experimentally determine the total volume of blood in a human?
*November 6, 2011*

**Science**

Are you then suggesting that because humans are not predators, their eyes have a more constricted view than owls?
*November 6, 2011*

**Science**

Why are your ears at the side of your head and not in front where your eyes are?
*November 6, 2011*

**chemistry**

sample of argon gas collected at a pressure of 1.11 atm and a temperature of 28.0 oC is found to occupy a volume of 20.3 liters. How many moles of Ar gas are in the sample?
*November 5, 2011*

**Physics**

A rock thrown with an initial velocity of 35 m/s at an angle of 48° with respect to the horizontal has a range of 963 m on a certain planet. What is the acceleration of gravity on this planet?
*November 4, 2011*

**MATH**

Assume that the population of heights of male college students is approximately normally distributed with mean of 72.83 inches and standard deviation of 6.86 inches. A random sample of 93 heights is obtained. Show all work. (A) Find the mean and standard error of the x ...
*November 3, 2011*

**MATH...PLZ HELP**

The width of the Confidence Interval is inversely related to the Maximum Error of Estimate. T or F? Why or why not?
*November 3, 2011*

**MATH....**

Determine the level of the confidence given the confidence coefficient z(α/2) for the following situation: z(α/2) = 1.96
*November 3, 2011*

**MATH**

Given a binomial distribution with n = 21 and p = 0.76, would the normal distribution provide a reasonable approximation? Why or why not?
*November 2, 2011*

**Math**

pattern rule for 2,3, ___, 7, 11, 13, 17, ___
*November 2, 2011*

**physics**

thank you so much!!!
*November 2, 2011*

**physics**

thank you! From here how would I get this: Suppose the torque you found for the last part is being produced by a force applied at a point 0.15·m from the axis. If the direction of the force is perpendicular to a line from the axis to that point, what is the magnitude of...
*November 2, 2011*

**physics**

Consider a 8·kg rod with a length of 0.6·m and rotating about an axis passing through its center. (a) What is its rotational inertia? (B) Suppose the rod is rotating counterclockwise and speeding up with a rotational acceleration of 7·rad/s2. What is the ...
*November 2, 2011*

**math**

Consider a 8·kg rod with a length of 0.6·m and rotating about an axis passing through its center. (a) What is its rotational inertia?
*November 2, 2011*

**math**

Consider a 8·kg rod with a length of 0.6·m and rotating about an axis passing through its center. (a) What is its rotational inertia?
*November 2, 2011*

**Biology**

Can genetic mutations also occur within mitochondria and cause diseases? if yes, how common are these diseases?
*October 31, 2011*

**Chemistry**

Hydrogen sulfide is an impurity in natural gas that must be removed. One common removal method is called the Claus process, which relies on the reaction: 8 H2S(g) + 4 O2(g)--> S(l) + 8 H2O(g) Under optimal conditions the Claus process gives 98% yield of S8 from H2S. If you ...
*October 31, 2011*

**Chemistry**

Which of the following solutions is the most basic? (a) 0.6 M NH3, (b) 0.150 M KOH, (c) 0.100 M Ba(OH)2. Explain.
*October 31, 2011*

**MATH**

A set of 50 data values has a mean of 18 and a variance of 4. I. Find the standard score (z) for a data value = 20. II. Find the probability of a data value < 20.
*October 30, 2011*

**math**

nevermind got it :-)
*October 27, 2011*

**math**

A large truck with a mass of 6500·kg and going 20·m/s east collides with a car whose mass is 1100·kg and which is at rest. If the impulse exerted on the car by the truck is 12000·N·s east, find the impulse exerted by the car on the truck. ...
*October 27, 2011*

**math**

Thank you sooo much!!! I wasnt dividing by the right number! can you also explain how to find the impulse of this problem? A large truck with a mass of 6500·kg and going 20·m/s east collides with a car whose mass is 1100·kg and which is at rest. If the ...
*October 27, 2011*

**MATH**

i'm not sure how that site relates to my question at all???
*October 27, 2011*

**MATH**

Find the z-score for the standard normal distribution where: Area = 0.95 to the left of z
*October 27, 2011*

**MATH**

What percentage of the area of the standard normal distribution is between z = -1.00 and z = +1.00? How do you know this?
*October 27, 2011*

**Did i do this right??? STATS**

3. In testing a new drug, researchers found that 10% of all patients using it will have a mild side effect. A random sample of 14 patients using the drug is selected. Find the probability that: (A) exactly two will have this mild side effect (B) at least three will have this ...
*October 26, 2011*

**Math**

In testing a new drug, researchers found that 10% of all patients using it will have a mild side effect. A random sample of 14 patients using the drug is selected. Find the probability that: (A) exactly two will have this mild side effect (B) at least three will have this mild...
*October 26, 2011*

**math**

block A: mass = 100·g, spring stretched 10·cm block B: mass = 400·g, spring stretched 20·cm block C: mass = 200·g, spring stretched 20·cm block D: mass = 200·g, spring stretched 20·cm Rank the blocks, from largest to ...
*October 25, 2011*

**chemistry**

write a balanced equation for photosynthesis. express the answer as a chemical equation. identify all of the phases in the answer. during photosynthesis, plants use energy from sunlight to form glucose (C6H12O6(s)) and oxygen from carbon dioxide and water
*October 25, 2011*

**chemistry**

honestly all we do is labs during class i would love to take notes
*October 25, 2011*

**chemistry**

we dnt take notes thats why im so lost
*October 25, 2011*

**chemistry**

use standard enthalpies of formation to calculate delta Hrxn for the following reaction. 2H2S(g)+3O2(g)-->2H2O(l)+2SO2(g) express the answer using four significant figures Delta Hrxn = ? kJ
*October 25, 2011*

**chemistry**

use standard enthalpies of formation to calculate delta Hrxn for the following reaction. 2H2S(g)+3O2(g)-->2H2O(l)+2SO2(g) express the answer using four significant figures Delta Hrxn = ? kJ
*October 25, 2011*

**Stats....PLZ HELP....**

A bag of colored blocks contains the following assortment of colors: red (18), blue (14), orange (20), purple (14), green (10), and yellow (4). Construct the probability distribution for x.
*October 25, 2011*

**Stats**

Find the mean and standard deviation of the following probability distribution: x 1 2 3 P(x) 0.3 0.5 0.2
*October 25, 2011*

**Stats**

x y 1 -10.0 2 -20.0 3 -30.0 4 -40.0 5 -50.0 - What would be the slope of this regression line? - Would the correlation between x and y be positive or negative? - How would you interpret these data in terms of linear regression?
*October 25, 2011*

**Stats**

In testing a new drug, researchers found that 10% of all patients using it will have a mild side effect. A random sample of 14 patients using the drug is selected. Find the probability that: (A) exactly two will have this mild side effect (B) at least three will have this mild...
*October 25, 2011*

**math**

Consider the experiment of simultaneously tossing a fair coin and rolling a fair die. Let X denote the number of heads showing on the coin and Y the number of spots showing on the die. a. List the outcomes in S. b. Find Fx,y(1,2). Part a is easy. It's part b that I don'...
*October 25, 2011*

**eth**

should united states government policy favor certain kinds of immigrants?
*October 23, 2011*

**statistics**

Seventy million pounds of trout are grown in the U.S. every year. Farm-raised trout contain an average of 32 grams of fat per pound, with a standard deviation of 7.5 grams of fat per pound. A random sample of 34 farm-raised trout is selected. The mean fat content for the ...
*October 23, 2011*

**statistics**

Seventy million pounds of trout are grown in the U.S. every year. Farm-raised trout contain an average of 32 grams of fat per pound, with a standard deviation of 7.5 grams of fat per pound. A random sample of 34 farm-raised trout is selected. The mean fat content for the ...
*October 23, 2011*

**Math**

You are given the following data. # of Absences Final Grade 0 96 1 92 2 71 3 66 4 60 5 51 A. Find the correlation coefficient for the data. B. Find the equation for the regression line for the data, and predict the final grade of a student who misses 3.5 days.
*October 21, 2011*

**Math**

Three cards are selected, one at a time from a standard deck of 52 cards. Let x represent the number of tens drawn in a set of 3 cards. (A) If this experiment is completed without replacement, explain why x is not a binomial random variable. (B) If this experiment is completed...
*October 21, 2011*

**Math**

A. If the correlation coefficient is 0.65, what is the sign of the slope of the regression line? B. As the correlation coefficient decreases from -0.97 to -0.99, do the points of the scatter plot move toward the regression line, or away from it?
*October 21, 2011*

**Math**

This is so confusing to me :( what would i do next??
*October 21, 2011*

**Math**

For the table that follows, answer the following questions: x y 1 1/2 2 1 3 3/2 4 - Would the correlation between x and y in the table above be positive or negative? - Find the missing value of y in the table. - How would the values of this table be interpreted in terms of ...
*October 21, 2011*

**Can somehelp me with this ASAP plz?!?!?! Stats**

For a particular sample of 63 scores on a psychology exam, the following results were obtained. First quartile = 57 Third quartile = 87 Standard deviation = 9 Range = 51 Mean = 72 Median = 72 Mode = 98 Midrange = 57 I. What score was earned by more students than any other ...
*October 19, 2011*

**Stats**

In each of the four examples listed below, one of the given variables is independent (x) and one of the given variables is dependent (y). Indicate in each case which variable is independent and which variable is dependent. I. Rainfall; Crop yield II. Taxi fare; Length of ride ...
*October 19, 2011*

**Stats**

For a particular sample of 63 scores on a psychology exam, the following results were obtained. First quartile = 57 Third quartile = 87 Standard deviation = 9 Range = 51 Mean = 72 Median = 72 Mode = 98 Midrange = 57 I. What score was earned by more students than any other ...
*October 19, 2011*

**Stats....how do i do this??**

It doesn't show .16, it shows .15 as p-value of 0.4404 and z as 1.15....what do i do??
*October 18, 2011*

**Stats....how do i do this??**

SAT I scores around the nation tend to have a mean scale score around 500, a standard deviation of about 100 points, and are approximately normally distributed. What SAT I score within the population would have a percentile rank of approximately 16? Im not sure how to do this...
*October 18, 2011*

**Stats...is this correct??**

Scores on the Stanford-Binet Intelligence scale have a mean of 100 and a standard deviation of 16, and are presumed to be normally distributed. A person who scores 68 on this scale has what percentile rank within the population? z = (68-100)/16 z = -32/16 = -2 So would it be ...
*October 18, 2011*

**Stats...is this correct?**

Yay!! Thank u!!
*October 18, 2011*

**Stats...is this correct?**

A sample of purchases at the local convenience store has resulted in the following sample data, where x = the number of items purchased per customer and f = the number of customers. x 1 2 3 4 5 f 5 15 8 8 7 1. What does the 15 stand for in the above table? 2. Find the midrange...
*October 18, 2011*

**Stats**

I. Dependent variable; Independent variable II. Independent variable; Independent variable III. Independent variable; Dependent variable IV. Dependent variable; Dependent variable Sorry I misread it. Is this correct?
*October 18, 2011*

**Stats**

6. In each of the four examples listed below, one of the given variables is independent (x) and one of the given variables is dependent (y). Indicate in each case which variable is independent and which variable is dependent. I. Rainfall; Crop yield II. Taxi fare; Length of ...
*October 18, 2011*

**Stats**

For a particular sample of 63 scores on a psychology exam, the following results were obtained. First quartile = 57 Third quartile = 87 Standard deviation = 9 Range = 51 Mean = 72 Median = 72 Mode = 98 Midrange = 57 I. What score was earned by more students than any other ...
*October 18, 2011*