Saturday
December 3, 2016

# Posts by Rachel

Total # Posts: 1,501

Chemistry
A small pebble is heated and placed in a foam cup calorimeter containing water at 25 °C. The water reaches a maximum temperature of 27 °C. If the pebble released 532.1 J of heat to the water, what mass (in g) of water was in the calorimeter?
April 30, 2014

Chemistry
If 82.4 g of cold water (initially at 22 °C) is mixed in an insulated container with 96 g of hot water (initially at 88 °C), what will be the final temperature of the water in °C?
April 30, 2014

Calculus
if the work required to stretch a spring 1 ft beyond its natural length is 12 ft-b, how much work is needed to stretch 9 inches beyond its natural length?
April 30, 2014

Math
A ball is thrown downward from the top of a 100-foot building with an initial velocity of 14 feet per second. The height of the ball h after t seconds is given by the equation h=-16t^2-14t+100. How long after the ball is thrown will it strike the ground?
April 28, 2014

Algebra
How can I solve 1/2x+1/x=-12?
April 16, 2014

Chemistry
. 0.1M Urea
April 10, 2014

physics
A weight oscillates in a vertical motion according to the position function y(t)=-5cos t. Assuming t>=0 (greater than or equal to), when will the acceleration of the weight be zero for the first time?
March 27, 2014

math
Thomas bought a 3-foot sandwich for his .Hew figured out that each guest can have 1 1/2 inches of the sandwich . HOW MANY guest does Thomas have.
March 24, 2014

algebra
FOR CA STUDENTS!!! 1. A 2. B 3. D 4. D 5. A
March 5, 2014

Consumer Math
I am purchasing a house for \$235,000 and have excellent credit. If I pay \$1,678.93 at the end of the first month, how much is applied to the principal balance?
March 3, 2014

algebra
Here are the answers for the whole QC for CA students. 1. C 2. A 3. no 4. c 5. A
March 1, 2014

Science
One gram of platinum has 3.09 × 1021 atoms, and each platinum atom has 78 electrons. How many electrons are contained in 4.00 g of platinum? The elemental charge is 1.6 × 10−19 C. Answer in units of electrons
February 26, 2014

Algebra II
Suppose that the profit, p, for selling bumper stickers is given by p(x) = 0.1x2 + 8x - 50. What is the minimum number of bumper stickers that must be sold to make a profit? a. 6 c. 10 b. 2 d. 15
February 25, 2014

algebra
Yes ashley
February 24, 2014

Math
sally bakes two cakes, a square and a circle. the length of the side of the square cakes is 8 inches. find the perimeter of the cake (the cake is in the shape of hearth )
February 22, 2014

SCIENCE HELP ASAP! :)
5 is a. 7 is d. 10 is a.
February 19, 2014

Physics
1. Two points in a plane have polar coordinates (2.5 m, 30 degrees) and (3.8 m, 120 deg). Determine (a) the cartesian coordinates of both points and (b) the distance between the points. 2. Vector A has magnitude 29 units and points along +y. When vector B is added to the ...
February 17, 2014

Math
3 similar shirts and 4 similar jackets cost \$360. 1 such shirt and 3 such jackets cost \$220. Find the cost of each shirt.
February 16, 2014

Calculus
Line l is tangent to the graph of y= x - x²/500 at point Q & it crosses the y-axis at (0, 20) a). Find the x-coordinate of point Q b. Write an equation for line l c) Suppose the graph of y=x-x^2/500, where x and y are measured in feet, represents a hill. There is a 50-...
February 15, 2014

chem
How do I calculate the rate of a reaction of a substance using the slope of the lines and stoichiometry of the reactions in moles/sec. I also know that the molarity of that substance.
February 13, 2014

Calculus
The position of a function of a moving particle is s(t)=5+4t-t^2 for 0<t<10 where s is in meters and t is measured in seconds. What is the maximum speed in m/sec of the particle on the interval [0,10]?
February 13, 2014

Calculus
Let f be the function defined by f(x)=x^3 + x. If g(x)= the inverse of f(x), and g(2)=1, what is the value of g'(2)?
February 13, 2014

math
Find the altitude of an isosceles triangle whose base is 8 cm and whose legs are 5 cm?
February 13, 2014

chemistry
Three part question Two students each measured the density of a quartz sample three times: Student A Student B 1. 3.20g/mL 2.82g/mL 2. 2.58g/mL 2.48g/mL 3. 2.10g/mL 2.59g/mL mean 2.63g/mL 2.63 g/mL a. which student measured density with the greatest precision? explain your ...
February 11, 2014

chemistry
The directions state "weigh about 5 grams of sodium chloride". Give minimum and maximum amounts of sodium chloride that would satisfy these instructions.
February 11, 2014

Physics
A car is speeding up in the forward direction on a level road. a. The frictional force acting from the road on the tires is pointed forward. b. The frictional force acting from the road on the tires is pointed backward. c. There is not enough information to determine the ...
February 3, 2014

Spanish
Tienes
January 31, 2014

Calculus
Thank you!
January 31, 2014

Calculus
Let f be the function given by f(x)= 2x/(sqrt(x^2 +x +1)) c. Write an equation for each horizontal asymptote of the graph of f. d. Find the range of f. Use f'(x) to justify your answer.
January 31, 2014

Math
Jody deposited \$65 into her savings account. The next day, she withdrew \$24. how much of her deposit remains in the account?
January 30, 2014

Calculus
Let g and h be any two twice-differentiable functions that are defined for all real numbers and that satisfy the following properties for all x: I) (g(x))^2 + (h(x))^2=1 ii) g'(x)= (h(x))^2 iii) h(x)>0 iv) g(0)=0 a)Justify that h'(x)=-g(x)h(x) for all x b) Justify ...
January 30, 2014

English
I have an art presentation and I need to find a piece of literature written around late 1800s to early 1900s to relate to my art (The Brooklyn Bridge photograph- Walker Evans). It'll probably need to be industrialization related. Thanks.
January 26, 2014

Math
2 5/8 divided by 7= Answer in simplest form
January 22, 2014

science
Why did Charles Darwin talk about pigeons (how breeders produced many shapes, sizes, and colors of pigeons, all starting from a wild pigeon) in his book On the Origin of Species?
January 21, 2014

PHYSICS
A crate is pushed horizontally with a force. The acceleration of gravity is 9.8 m/s2 . Calculate the acceleration of the crate. Answer in units of m/s2 1570 N 198 kg μ = 0.44
December 18, 2013

physics
A 1900 kg car moves along a horizontal road at speed v0 = 26.4 m/s. The road is wet, so the static friction coefficient between the tires and the road is only μs = 0.17 and the kinetic friction coefficient is even lower, μk = 0.119. The acceleration of gravity is 9.8...
December 18, 2013

geometry
A diameter of a circle is perpendicular to a chord whose length is 12 inches. If the length of the shorter segment of the diameter is 4 inches, what is the length of the longer segment of the diameter?
December 3, 2013

geometry
A diameter of a circle is perpendicular to a chord whose length is 12 inches. If the length of the shorter segment of the diameter is 4 inches, what is the length of the longer segment of the diameter?
December 3, 2013

geometry
A diameter of a circle is perpendicular to a chord whose length is 12 inches. If the length of the shorter segment of the diameter is 4 inches, what is the length of the longer segment of the diameter?
December 3, 2013

geometry
Two secant segments are drawn to a circle from a point outside the circle. The external segment of the first secant segment is 8 centimeters and its internal segment is 6 centimeters. If the entire length of the second secant segment is 28 centimeters, what is the length of ...
December 3, 2013

geometry
Two secant segments are drawn to a circle from a point outside the circle. The external segment of the first secant segment is 8 centimeters and its internal segment is 6 centimeters. If the entire length of the second secant segment is 28 centimeters, what is the length of ...
December 3, 2013

Math
12; 3/12 is reduced down to 1/4
November 14, 2013

math
a. n/16
November 14, 2013

Physics
Calculate the water pressure at the bottom of the 100-m-high water tower
November 10, 2013

Physics
How much force is needed to hold a nearly weightless but rigid 1-L carton beneath the surface of water?
November 10, 2013

Physics
A certain spring stretches 5.8cm when a load of 38N is suspended from it. How much will the spring stretch if 48N is suspended from it (and it doesn't reach its elastic limit)?
November 10, 2013

science
A I no. I love so😵😲😤😖
November 10, 2013

Math
Mortgage lenders base the mortgage interest rate they offer you on your credit rating. This makes it financially critical to maintain a credit score of 700 or higher. How much more interest would you pay on a \$195,000 home if you put 20% down and financed the remaining with a ...
November 9, 2013

MATH
Find the y- intercept of the graph of each function. y=3x+3
November 6, 2013

US History/Literature
What specific literary connection (Romanticism) can I make from John Mix Stanley's painting, "Osage Scalp Dance?"
November 4, 2013

Health
You have to show You have courage in yourself
October 23, 2013

Math
There are 22 gloves in a drawer. 5 brown pair, 4 green pair, and 2 blue pair. If you had the reach into the drawer and it was dark, how many must you choose to ensure that you have a matching pair?
October 20, 2013

Math check
If the angle is supplementary to another angle that would mean it would have to be verticle to itself. Since there are 360 degrees in a circle and you are trying to figure 4 angles you do 57+57 and get 114. You then subtract that from 360 to get 246. Since you are putting that...
October 20, 2013

A coffin is given an initial speed of 4.4 m/s up the 17.8º inclined plane with a coefficient of kinetic friction of 0.4. How far up the plane will it go?
October 16, 2013

Science
A coffin is given an initial speed of 4.4 m/s up the 17.8º inclined plane with a coefficient of kinetic friction of 0.4. How far up the plane will it go?
October 16, 2013

math
Danny has a 15-foot board that he wants to use as a motorcycle ramp. If Danny wants the end of the ramp to be 4 feet off the ground, what angle will be formed between the board and the ground?
October 10, 2013

CHEMISTRY........
Danny has a 15-foot board that he wants to use as a motorcycle ramp. If Danny wants the end of the ramp to be 4 feet off the ground, what angle will be formed between the board and the ground?
October 10, 2013

Chemistry
Convert 355.3 kg to tons. I start the problem: 355.3 kg to 1 kg then 1 x 10 to the third power, then I have 1g. My problem is that I don't know what to do with my 1 g. What is the next step?
October 1, 2013

An important factor of being judged a best company to work for is the input provided by company employess.
September 21, 2013

physics
A space probe has two engines. Each generates the same amount of force when fired, and the directions of these forces can be independently adjusted. When the engines are fired simultaneously and each applies its force in the same direction, the probe, starting from rest, takes...
September 15, 2013

Chemistry
A glass can be filled slightly above the rim with water. Explain why the water does not overflow.
September 7, 2013

Chemistry
Identify the predominant intermolecular forces between molecules of each of the following compounds: a. CCl4 b. HF c. SO2 d. CH3COOH e. HI
September 7, 2013

Chemistry
Predict which compound from each of the following pairs will have the highest boiling points and why? NH3, He, Ar, LiF
September 7, 2013

jru-physics
what potential energy is acquired by a block of steel whose mass is 50 kg when it is raised 200 cm?
September 4, 2013

Physics
Julie throws a ball to her friend Sarah. The ball leaves Julie's hand a distance 1.5 meters above the ground with an initial speed of 24 m/s at an angle 32 degrees; with respect to the horizontal. Sarah catches the ball 1.5 meters above the ground. What is the maximum ...
September 3, 2013

Math
OF ALL THE SHIRTS aRTHUR`S WARDROBE, HALF ARE BLUE, ONE-QUARTER ARE WHITE AND ONE-EIGHT ARE STRIPED, THE REMAINING TWO SHIRTS ARE PLAID. HOW MANY SHIRTS DOES ARTHUR HAVE ALTOGETHER?
September 2, 2013

Physics
If theta equals 60 and F equals 450 Newtons, determine the magnitude of the resultant force and its direction, measured counterclockwise from the positive x axis.
August 28, 2013

Chemistry II
Consider the following balanced chemical equation: 3(NH4)2CrO4 + 4Al + 24HCl --> 3CrCl2 + 6NH4Cl + 4AlCl3 + 12H2O. a) How many moles of HCl would be required for the reaction of 0.0123 moles Al? b) How many grams Al would be required for the reaction of 2.00g (NH4)2CrO4? ...
August 26, 2013

Bus management
the first step in developing the compensation plan for a sales force is to:
August 15, 2013

geometry
consider a circle of radius 1, and corresponding inscribed and circumscribed polygons with the number of sides n = 3, 4, 5, 6, and 8. A: For each n = 3, 4, 5, 6 & 8, what are the areas of the inscribed and circumscribed polygons with n sides?
July 27, 2013

Is "pharmacy" a business or a profession?
July 5, 2013

algebra 2
Consider the exam data below. Algebra score: 20 35 13 29 40 23 Calculus score: 41 69 34 72 86 58 Use your calculator to find the regression line for this data, and graph it on your scatterplot. b. Interpret the slope and intercepts of this line in the context of the problem. c...
July 5, 2013

Physics
d=1/2gt^2 acceleration due to gravity= 32 ft/s^2 100= 1/2(32)t^2 100=16t^2 100/16 = 6.25 t^2= 6.25 t= 2.5
June 14, 2013

Maaaath
a stone thrown upward from the top of a 320-foot cliff at 128 ft/sec eventually falls to the beach below? how long does the stone take to reach its highest point?
June 13, 2013

success in college requires:
June 11, 2013

Math
D. The mean of the first three tests.
June 4, 2013

math
Find the area of the other figure to the nearest whole number. The area of the smaller trapezoid is 771 m2.
May 21, 2013

math
An unknown radioactive element decays into non-radioactive substances. In 100 days the radioactivity of a sample decreases by 64 percent. a)(a) What is the half-life of the element? half-life: b)How long will it take for a sample of 100 mg to decay to 51 mg? time needed:
May 18, 2013

math
If a number increases from 47 to 70.5 what is the rate of increase?
May 15, 2013

math
What is 7,000 decreased by 62%?
May 15, 2013

chem
the mass of the oxygen (o2) in a room is 0.0568 grams. How many oxygen molecules are in the room. 2 conversions are needed.
May 15, 2013

world civilization
which of these ancient civilizations survived, intact, until the twentieth century?
May 9, 2013

algebra 2
A dog kennel is to be constructed alongside a house using 60 m of fencing. Find the dimensions that will yield the maximum area. How do you solve this problem?
May 8, 2013

chemistry
a block of aluminum is placed in 10.0g of water. the initial temperature of the water is 22.0 degrees celcious and its final temperature is 27.0 degrees celcious. what is the amount of heat released by the block of aluminum in calories if it had an initial temperature of 48.0 ...
April 30, 2013

Biology
i love bio i thinks its lifes greatests moments like you can do labs and fill out reports just like a real scientist
April 29, 2013

Biology
biology isnt hard you just have to work at it and you should take good notes and pass the class cause if you don't youll fail the test lol
April 29, 2013

physics
Construct a 5th mode standing wave on a string that has an unknown mass hanging from one end. The distance between fixed ends of the string is 0.9 meters. If the wave speed on the 1.3 meter string is 216 meters per seconds and the string has a mass of 3 grams, what is the ...
April 28, 2013

spanish
Donde compraste esa falda cara?
April 24, 2013

english
What kind of fallacy are these 2 examples? 1. "Fresh fruits and veggies make life better." 2. "Fairway coffee is the essence of life itself."
April 22, 2013

Physics
A string fixed at both ends is 9.31 m long and has a mass of 0.125 kg. It is subjected to a tension of 100.0 N and set oscillating. (a) What is the speed of the waves on the string? m/s (b) What is the longest possible wavelength for a standing wave? m (c) Give the frequency ...
April 16, 2013

Physics
A projectile is fired vertically from Earth's surface with an initial speed v0. Neglecting air drag, how far above the surface of Earth will it go? (Use any variable or symbol stated above along with the following as necessary: ME for the mass of the Earth, rE for the ...
April 11, 2013

tg3x-1=0
Find solutions
April 11, 2013

physics
The mean diameters of X and Y, two planets in the same solar system, are 7.0 103 km and 1.4 104 km, respectively. The mass of X is 0.15 times the mass of Y. The value of g on Y is 8.6 m/s2. (a) What is the ratio of the mean density of X to that of Y (ρX / ρY)? (b) ...
April 8, 2013

Physics
Divide the negative charge by two. Since the total charge of the dipole is zero, you must have the two positive charges (which are the same), cancel out the sole negative charge. -15.9/2 = -7.95, and then flip the sign because the two sides are positive, so +7.95µC
April 2, 2013

government?
C. principle of popular sovereignty
March 28, 2013

physics
A man lifts various loads with the same lever. The distance of the applied force from the fulcrum is 2.00 m and the distance from the fulcrum to the load is 0.500 m. A graph of resistance force vs. effort force is shown. What is the mechanical advantage of the lever? What is ...
March 20, 2013

math
105.4
March 12, 2013

chemistry
A white solid was found in an unmarked bag. Describe an experiment that can be set up to determine if the solid is either MgSO4*10H2O or KCL*2H2O
March 4, 2013