# Posts by mary

Total # Posts: 3,822

**Chemistry **

calculate the delta G^o and Kc for the reaction: 2Al + 3I2 = 2Al^3+ + 6I-

**Chemistry**

The delta G^o for a reaction : h2 (g) + i2 (g) = 2HI(g) Is 2.6 kj/moles. In one experiment the initial pressures are P h2 = 4.26 atm, P i2 = 0.024 atm, P hi = 0.23 atm. Calculate delta G

**Chemistry**

The delta G^o for a reaction : h2 (g) + i2 (g) = 2HI(g) Is 2.6 kj/moles. In one experiment the initial pressures are P h2 = 4.26 atm, P i2 = 0.024 atm,

**stats**

Consumer Reports rated airlines and found that 80% of the flights involved in the study arrived on time (that is within 15 minutes of scheduled arrival time). Assuming that the on-time arrival rate is representative of the entire commercial airline industry, consider a random...

**science**

2. Compare and contrast deductive reasoning and inductive reasoning. Based on the information given here, answer the following questions about the experiment: • What are the qualities of deductive reasoning? • What are the qualities of inductive reasoning? • ...

**Math**

Start at 500. Create a pattern that subtracts 4 from each number. Stop when you have 5 numbers.

**Math**

Store a has a promotion if you Bryce three shirts you get 25% off the total price of the three shirts store be has the same shirts on sale with a promotion that if you buy three shirts you get the third shirt on a 50% discount store see has the same shirts on sale with a ...

**math**

If two trapezoids have the same perimeter do they have the same area?

**Maths**

60?

**English**

What are some of the differences between old money and new money characters in the great gatsby? Is this distinction important in today's society? Why is the novel narrated from Nick's perspective?

**Algebra **

One number is 2/3 of another number. The sum of the two numbers is 40. Find the two numbers. Use a comma to separate your answers.

**English**

how does the history of the American Dream show a difference between our ideals and the reality of growing inequality and lack of social mobility.

**Math**

The ratio of blue to red cars in a parking lot is 4/7. If there are 168 blue cars about how many red cars are there? 4/7=x/168 672=7x x=96

**math- integral**

Find the derivative of: G(x) = ?(top x) t^5 sin(?7t?4)dt . (bottom 9)

**Math**

How do I find the value of sin ( A-B) When tan A= 4/3 Cot B= 5/12

**physic**

Two currents from different sources flow in opposite directions through a resistor. I1 is measured as 79 mA on a 100 mA analog instrument with an accuracy of ±3% of full scale. I2, determined as 31 mA, is measured on a digital instrument with a ±100 µA ...

**math**

Find the degree 7 Taylor polynomial for f(x )= 2cos(3x) centered at x = 3?/2 . Thanks for your help

**core mathematics **

Two boats are 70m and on opposite sides of a lighthouse.from the two boats,the angles of elevation of the lighthouse are 71 and 45 respectively.find the height of the lighthouse.

**Chemistry**

Consider 1.00 L of the buffer system that contains 0.200 M hydrocyanic acid(HCN) and 0.150 M sodium cyanide (NaCN). The pKa of hydrocyanic acid is 9.31. What is the [HCN] after 0.020 mol of HCl is added?

**alegebra**

A study recently confirmed that of every 100100 citizens of a certain? state, 6060 are considered overweight. There were 299299 million citizens of this state in 2001. How many would be considered? overweight? nothing million citizens would be considered overweight.

**Physics**

How much does it cost to operate a 23-W porch light for 24 h if electric energy costs 8¢/kWh?

**math**

A college student takes a standardized test and scores a 163. If the mean is 155 and the standard deviation is 7, what is the student’s percentile rank? (Assume a normal distribution.)

**Physics**

1. Calculate the kinetic energy of a 5.2kg object moving at 2.4 m/s 7. Calculate the potential energy of a 5.2kg object positioned 5.8m above the ground 21. Calculate the speed of a 5.2 kg object that possesses 26.1 J of kinetic energy.

**Grade 6: money and measures**

12

**chemistry**

a student performs the lab on an unknown metal and obtain the following data

**Physics**

a=47.6-0/17.6 a=2.705 seconds

**Physics**

The velocity graph of a particle moving along the x-axis is shown. The particle has zero velocity at t=0.00s and reaches a maximum velocity, vmax, after a total elapsed time, t total. If the initial position of the particle is x0 =6.22m, the maximum velocity of the particle is...

**Physics**

t= sqrt (8.306) = 2.88s d= 234m/s * 2.88s = 674.40m Thanks!

**Physics**

A cannon ball is fired horizontally from a cannon that is 40.7m above the ground. The initial velocity of the cannon ball is 234m/s. How much time does the cannon ball spend in the air?

**Math**

cos(x)/(1-tan(x)) + (sin (x))* cos(x))/ sin (x)-cos(x))

**chemistry**

the value would be too high because the density should have had a denominator that was a bit lower and a numerator of grams

**chemistry**

a pipet can be calibrated. we expected the volume to be 25.00ml, but the actual volume was significantly less. if you had measured the density of an unknown with this pipet and assumed that v=25.00ml, your result would not be correct. would it be too high or too low? Explain

**Science**

The surface r of a liquid depends on the density p acceleration due to gravity g nd height h use the method of dimension to derive the actual relationship between this quantities. An object is tie to the end of a string move in a circle the force exerted by the string depend ...

**chemistry**

Express the composition of each of the following compounds as the mass percents of its elements...? 59) Express the composition of each of the following compounds as the mass percents of its elements. a) formaldehyde, CH2O b) glucose, C6H12O6 c) acetic acid, HC2H3O2

**Math**

How do you find P if A=1/2a+P, and you have both the values of a and A?

**Writing Skills**

Just took the test and it actually was C. reference book

**Writing Skills**

B. Medicine, Thank you for the help

**Writing Skills**

The call number of the book that you're looking for is R865.2. What do you know about the book based on this information? A. It's a book of or about Roman literature. B. It's a book about medicine. C. It's a reference book. D. It's a book that can be gained...

**History**

If The British Government Could Do It Over Again The British governing policy of salutary neglect gave the young colonial governments a chance to "experiment" with their own self-governance. Gaining confidence in their abilities to rule the people without the British...

**Math**

Susie spent 4 1/4 hours on Monday and 3 5/8 hours on Tuesday working on a history project. About how long did she spend working on the project?

**Civic education**

alienable fundamental rights to whichie inherently entitled sumply because he or she is a human being.

**algebra**

I have to write and solve as literal equation.

**algebra**

I want to visit a friend that lives 200 miles away. Gas is $4 a gallon. My car gets 50 miles every 2 gallons of gas. How can I solve this using an literal equation?

**Maths**

A right circular cone of base radius 5 cm and depth 20 cm is held with its vertex downwards. If water is leaking through a small hole in the vertex at the rate of 8 cm^3/s, find the rate of change of the water level in the cone when the radius of the water surface is 4cm, ...

**Math**

The total number of football (x) and basketball (y) is 180. There are 30 more football than basketball. How many of each basketball and football are there?

**Physics**

Hello, Could anyone help me with something about rolling motion? Well the question is the next: Does static friction cause a positive work in the rolling motion? I really don't get how the static friction is involved in rolling and if it causes work Please help

**Algebra**

Hello....I was helped on this question earlier, but I don't understand why we divide by 2? Please help, please see the below: The president will order 5 turkey sandwich combos and 7 steak lunches and spends $124.00. The other president will get 10 turkey combos and 5 steak...

**Algebra**

Please help: The president will order 5 turkey sandwich combos and 7 steak lunches and spends $124.00. The other president will get 10 turkey combos and 5 steak combos for $140.00. How much is a turkey sandwich combo? Write a system of equation. 5x + 7y = $124.00 10x + 5y= $...

**Math**

The rating for a tv show dropped a total of 10 points in 2 weeks. What integer represents the average change in points per week?

**Physics**

ou build a loop-the-loop in your backyard. It has a diameter of 3.10 m. a) How fast will you have to be moving at the top of the loop to avoid falling off? b)If you'll be coasting from the time you get to the bottom of the loop, how fast will you have to be going at the ...

**Physics**

A 15 kg box is given an initial push to start it moving up a frictionless ramp with angle theta = 30 degree and length delta r = 22m. What horizontal force F will keep the box moving with constant speed to the top of the ramp?

**Physics**

Material X has a coefficient of linear expansion a = 0.00000271/degree C. What value would you expect its volume coefficient of expansion to be

**physics**

Suppose Captain Marvel leaps from the top of a 20 m tall building. If his initial speed is 12 m/s, then what is his speed just before he lands on the ground?

**maths**

if a room is 5500 sq metres the romm lenth is 6 times the width what is the length of the room

**Physics**

An aluminum (with Young's modulus 7 x 10^10 Pa) rail is 88.0 m long and has cross-sectional area 0.00050 m^2. The rail is fixed at one end and a 4000 N force is applied at the other end. By how much does the bar stretch?

**AP Calculus**

I am doing the 100 meter men's freestyle swimming lab (in case you know what I am referring to) and I need to fibd the lower limit analytically. I am given a table of data containing the years after 1900 and the time in second of each country , for example: Time. Country. ...

**math**

A(x)=x^2+6x^2 A(x)= 7x^2

**Physics**

A satellite orbits the Earth in an orbits 750 km high. Find (*) the satellite's orbital speed and (**) period. (The mass and radius of the Earth are 5.98E + 24 kg and 6370000 m, respectively.)

**English comp 1**

Revise the following paragraph, improving it without changing its overall meaning. Pay particular attention to any potential sentence fragments. I love Impressionist art. When I was a child, I went to the museum. The art museum. I stood in front of Monet'...

**science**

Thanks , that's exactlywhat I thought, but did something wrong when solving and thought I was wrong . THANKS!!

**science**

If a penny prior to 1982 weighted 3.1 grams and a current one weighs 2.5 grams how many pennies weighing 3.1 and 2.5 will I need in a combination of ten in total to have 25 grams??

**Physics**

An angle of a circle with a 2 m radius is delta theta = 20 degree. What is the corresponding arc length delta s?

**Physics**

A wheel is rotating with angular velocity 14 rev/s. What angular acceleration would be needed to bring the wheel to rest in a single rotation?

**math**

78, 69, 45, 89, 74, 37, 99, 77, 100, 82. What is the interquartile range of these scores?

**Math**

Test 62,004 for divisibility by 2, 3, 5, 9, or 10. Please help!!

**Math**

How do you write 1,840 in scientific notation?

**Math**

Write the expression using an exponent. 4^2 - (2 • 2^4) a -16 b 30 c -240 d 224 (-3)^3 a 0 b -9 c -27 d 27 37 • 5^2 - 9 • 4^2 a 9,472 b 781 c 256 d 2,816

**Chemistry**

What mass of hydrogen gas is produced when 3.0 mol of iron react with excess hydrochloric acid according to the reaction below 2Fe + 6HCl --> 2FeCl3 + 3H2

**Chemistry**

What mass of hydrogen gas is produced when 3.0 mol of iron react with excess hydrochloric acid according to the reaction below 2Fe + 6HCl --> 2FeCl3 + 3H2

**Chemistry**

What mass of hydrogen gas is produced when 3.0 mol of iron react with excess hydrochloric acid according to the reaction below 2Fe + 6HCl --> 2FeCl3 + 3H2

**Chemistry**

What mass of hydrogen gas is produced when 3.0 mol of iron react with excess hydrochloric acid according to the reaction below 2Fe + 6HCl --> 2FeCl3 + 3H2

**Chemistry**

What mass of hydrogen gas is produced when 3.0 mol of iron react with excess hydrochloric acid according to the reaction below 2Fe + 6HCl --> 2FeCl3 + 3H2

**physics**

A can of Coke moving 15.6 m/s toward the right(the positive direction) collides with a can of Pepsi moving 3.21 m/s toward the left, and both cans are badly crunched. If the final velocity of the can of Coke is 2.48 m/s still toward the right, then what is the final velocity ...

**SS**

how did Alexander Hamilton plan to pay off the national debt? by creating a population tax by printing new currency by taxing imports** by increasing exports

**Statistics**

Please help me with this homework you roll two fair dice, a green one and a red one? (a) are the outcomes on the dice independent? (b)Find P(1 on green die and 2 on red die) (c)Find P(2 on green die and 1 on red die) (d)Find P(1 on green die and 2 on red die) or (2 on green ...

**physics**

The answer is #4. I had that same question and got it right.

**Physics**

Several forces are applied to an object. If the object 40 m along the horizontal, and if one of the forces is a constant 5.0 N in the opposite direction, then what is the worst done on the object by that force?

**Ela**

Can you help me with the final check:Relating to Parents chapter 17

**calc**

How do I find the inverse of a picewise function???

**Math**

The diameters of a circle is 50cm how far does the wheel travel for 1 turn

**Physics**

You toss a tennis ball straight upward. At the moment it leaves your hand it is at a height of 1.3 m above the ground, and it is moving at a speed of 7.4 m/s. (a) How much time does it take for the tennis ball to reach its maximum height? (b) What is the maximum height above ...

**Statistics**

Write an inequality that represents all of the data values X, that fall between the values of the mean +/- the standard deviation

**college algerbra**

Describe how you know if an inequality is an “and” or an “or” problem. (use -3 < x+5 < 8).

**pre-calc**

e^-1 cost +sint(-e^-t)=0

**pre-calc**

Solve for t if 0<t<2pi Note: both are less than or equal to . Please help!! I am not sure what I should do.

**physics**

Two objects are positioned and moving . m 1 = 7 kg ,m 2 =11 kg, and the coefficient of kinetic friction between object 1 and the tabletop is uk = 0.14. Find the acceleration of object 2(assuming up is the positive direction) as well as the tension in the string.

**Chemistry**

These were all correct 100%

**Chemistry**

What do you mean "ok"? Are they correct?

**Chemistry**

1) How does the atomic radius change from left to right across a period in the periodic table? A) It tends to decrease*** B)It tends to increase C) It first increases, then decreases D) It first decreases, then increases 2) What is the charge of a cation? A) A positive charge...

**Math**

How many square tiles with sides 1 foot long would be needed to cover the floor of an 8' x 10' room

**Engineering**

Would someone please help me to set this problem up. Thanks

**Engineering**

If the cost of a .75 x 6.o x 19.0 sheet of ABS plastic is $18.00, what is the cost to make 20 parts? each part has a mass of .437lb.

**Engineering**

.437 lbs

**Engineering**

Damon the mass is .437 per part. It should be a simple problem for me but I am not sure right now. Thanks for your help.

**Engineering**

If the cost of a .75 x 6.0 x 19.0 sheet of ABS plastic is $18.00, what is the cost to make 20 parts?

**Chemistry**

1) How does the atomic radius change from left to right across a period in the periodic table? A) It tends to decrease*** B)It tends to increase C) It first increases, then decreases D) It first decreases, then increases 2) What is the charge of a cation? A) A positive charge...

**Science/Math**

You put 50 mL of water in a graduated cylinder, then you place an object in the water. The level rises to 55 mL. What is the volume of the object?

**Physics**

A projectile is launched horizontally from a cliff and has initial speed 30 m/s. The projectile will hit the ground 10 s later. What is the horizontal component of the projectile's velocity 5.0 s after launch. Assume air resistance is negligible.

**Physics**

A man chased by the army, leaps with speed 12 m/s at a 47 degree angle above the horizontal from the top of a building. If he lands 40.0 m from the base of the building, then finds the height of the building

**Math**

eat this hw t