# Posts by Rachel

Total # Posts: 1,592

**English**

How much control should students have over their education?

**ratios**

20

**English**

Amelia was too tired to walk her dog, after running the half marathon. Is that right? And thank you.

**English**

Rewrite the following sentences in order to correct the punctuation. In the morning Shelby ate a peanut butter sandwich and an apple she rode her bike to school. After running the half marathon; Amelia was too tired to walk her dog.

**math**

John and Smith went to a stationery shop. John bought 6 pens, 4 pencils and 3 erasers. Smith bought 3 pens, 8 pencils and 6 erasers and spent 20% more than John. What percentage money did John spend on pens? How can I form an equation and solve?

**math**

The sum of two numbers is 4 and the reciprocal of one exceeds the reciprocal of other by twice the product of their reciprocals. What is the product of the reciprocals of two numbers? Please help me solving.

**chemistry**

The number of protons in an anion must always be ________ the number of electrons. the same as We can’t tell. less than greater than

**chemistry**

A metal oxide will form an acid when it is dissolved in water. T/F

**chemistry**

When an acid and a base react in a neutralization reaction, the products will be acidic. T/F

**Chemistry**

Temperature is a measure of the amount of heat an object contains. T/F

**Chemistry**

An archeological artifact was subjected to radiocarbon dating. The artifact showed a carbon-14 decay rate of 13.8 disintegrations/ min per gram of carbon. Carbon-14 has a half-life of 5715 years, and currently living organisms decay at the rate of 15.3 disintegrations/ min per...

**math**

I don't know

**math**

A test had 200 questions .Each correct answer carried 2 marks.Each wrong answer carried -1/2 marks and unanswered question fetched no marks .Ajay attempted all the question in the test and he scored 360 marks.What would his marks be, if for each correct answer he got 1/2 marks...

**AP CALC. AB**

1. Let f be the function given by f(x)=x^2+4x-8. The tangent line to the graph at x = 2 is used to approximate values of f . For what value(s) of x is the tangent line approximation twice that of f ? I: -√2 II: 1 III: √2 Select one: a. III only b. I and III only c...

**Algebra**

What is the range of the function f(x)=3-2*51^x? Give your answer as an interval.

**Math**

Hi Reiny, Thank you for answering my question, but I don't think there is ã2 at the top because, my teacher said it is just supposed to be whole numbers in the denominator and numerator.

**Math**

No problem.

**Math**

10 divided by 4/5 is the same thing as multiplying it's reciprocal. 10 * 5/4 = 50/4 (All you have to do is flip 4/5 to 5/4) You can simplify 50/4 to 12 1/2.

**Science**

What would happen if cells didn't have the following? : -Nucleus -Ribosomes -Endoplasmic Reticulum -Cell Wall

**Algebra**

A kite is tied to the ground. The rays from the sun hit the kite perpendicular to the kite string, casting a shadow of the kite on the ground. The coordinates in the diagram are given in feet. What is the distance from where the kite is tied to the shadow? Coordinates are (3,...

**Statistic**

A major airline company is concerned that its proportion of late arrivals has substantially increased in the past month. Historical data shows that 18% of the company airplanes have arrived late. In a random sample of 1,240 airplanes, 310 airplanes have arrived late. a. ...

**Cal-help-Plz?**

Me confuseddd

**Cal**

Which of the following functions is continuous but not differentiable at x = 1? Functions: I.y=3√x-1 II.y={x^2,x≤1 2x,x>1 III. y={x,x≤1 1/x,x>1 I'm not really sure how to do this, but I've been trying and I keep getting both I and III.. am I ...

**CAL**

Okay I sure will! Thanks

**CAL-Reinyyy**

The equation is y= x cubed over x minus x so; y= x^3 / x -x Sorry for being confusingg

**AP CALC. AB**

A particle moves along a line so that at time t, where 0<=t<=pi, its position is given by s(t)= -4cost-((t^2)/2)+10 What is the velocity of the particle when its acceleration is zero? a. 8.13 b. 1.32 c. 0.74 d. -5.19 e. 2.55 I know that c and b are incorrect Please help me

**Algebra**

I don't understand

**Algebra**

What is the equation in the slope intercept form for the line that passes through the points (1,-3) and (3,1)? Y=3x+1 Y=x-3 Y=2x+5 Y=2x-5

**Algebra**

What is an equation in slope intercept form for the line that passes through the points (1,-3) and (3,1)?

**AP CALC. AB**

I am really confused on part 1. I don't even know what u did. For part 2 where did u get .75 and did you mean to solve for dh/dt

**AP CALC. AB**

Please help me with this problem and please walk me through each step i am really confused. Sand is falling from a rectangular box container whose base measures 40 inches by 20 inches at a constant rate of 300 cubic inches per minute. a) how is the depth of the sand in the box...

**AP Calc. AB**

If f(x)=2x+sin(x) and the function g is the inverse of f, then g'(2)=?? a. 0.40 b. 0.38 c. 0.34 d. 0.32 e. 0.36

**Finance**

The 6 percent, semi-annual bonds issued by Black Water Mills mature in 9 years and have a face value of $2,200. What is the current value of one of these bonds if the market rate of return is 11.10 percent?

**Chemistry**

do you know anyone who can help me with those questions if you do can you please let them know thanks

**Chemistry**

the one that says science rachel

**Chemistry**

did you write anything because it doesnt show

**science**

drbob222 can you please answer the science questions on my post

**science**

do you know anyone who can help me?

**science**

dr bob 222 or ms.sue can you please answer these questions

**math**

which number has the greatest value? a 3.5 b square root of 15** c square root of 1/16 d 26/100 which number is an irrational number? a 3.5 b square root of 36 c square root of 48 d 37/100*** If a is a rational number and b is an irrational number, then the sum a + b is A)...

**science**

1. Tommy performed an experiment to test the solubility of sodium chloride in water. After he completed his experiment, he discovered that he had a few unused grams of NaCl leftover in a beaker. What should he do with the excess NaCl? A. Pour the excess back into the original ...

**AP Calc. AB**

If f and g are functions such that f(g(x))=g(f(x))=x for all x in their domains, and if f(a)=b and f'(a)=c, then g'(b) =? a) g'(a)=1/c b) g'(b)=1/c c) g'(b)=-1/c d) g'(b)=1/a e) g'(a)=-1/c

**Chemistry**

3NO2(g) + H2O(l) → 2HNO3(aq) + NO(g) standard enthalpy: -133.5 Find the change in internal energy for this reaction. Enter in kJ.

**Statistics**

Suppose a certain species bird has an average weight of grams. Based on previous studies, we can assume that the weights of these birds have a normal distribution with grams. For a small group of 13 birds, find the margin of error for a 70% confidence interval for the average ...

**US History**

This is a letter from George Washington to Patrick Henry: September 24, 1787 I don't understand what his purpose and point of view is. Please help me!!! Dear Sir: In the first moment after my return I take the liberty of sending you a copy of the Constitution which the ...

**AP CALC. AB**

1.The position of a particle moving on the line y = 2 is given by x(t)= 2t^3-13t^2+22t-5 where t is time in seconds. When is the particle at rest? a. t =0.268, 2.500, and 3.732 b. t = 0, 1.153, and 3.180 c. t = 1.153, 2.167 and 3.180 d. t = 2.167 e. t = 1.153 and 3.180 2.A ...

**physics**

A cyclist maintains a constant velocity of 4.1 m/s headed away from point A. At some initial time, the cyclist is 244 m from point A. What will be his displacement from his starting position after 60 s?

**Economics**

explain why positive and negative externalities are market failures

**US History**

The Revolutionary War could be considered an international war. Explain if this statement is true or false using examples.

**US History**

Were the colonists politically independent before the French and Indian War?

**US History**

the seven years of war led to taxation without representation because of the debt that king george had to pay for. therefore this angered the colonies and was a turning point to english and colonists relationships

**US History**

i am writing an essay so i need to write about multiple reasons

**US History**

taxation without represent ions that the only one that i know

**US History**

Why was seven years of war a turning point in British colonial society and their relationship with England? Please give me 4 different reasons.

**physics**

A diver achieves a horizontal velocity of 3.76 m/s from a diving platform located 6m above the water. How far from the edge will the diver be when she hits the water?

**AP CALC. AB**

Let f(x)=3/x. If the rate of change of f at x = c is three times its rate of change at x = 2, then c = ?

**AP Calc. AB**

At how many points on the curve y=4x^5-3x^4+15x^2+6 will the line tangent to the curve pass through the origin?

**Social Studies**

angel, which answer did you get wrong?

**AP Calc. AB**

1.If an arrow is shot upward on the moon with a velocity of 50 m/s its height (in meters) after t seconds is given by H = 50t - 0.66t2. With what velocity will the arrow hit the moon? a. -49.5 b. -47 c. -50.1 d. -50 e. -51 2.If an arrow is shot upward on the moon with a ...

**math statistics**

A group of teenager smoking rate dropped 8.5% in 2007 from 17.6% in 2001 and 23% in 1997. 1. Calculate the probability that at least one in a group of 10 teenagers smoked in 2007.2. Calculate the probability that at least one in a group of 10 teenagers smoked in 2001. 1. ...

**statistics**

Teenage smoking rate dropped to 8.5% in 2007 from 17.6% in 2001 and 23% in 1997. 1. Calculate the probability that at least one in a group of 10 teenagers smoked in 2007. 2. Calculate the probability that at least one in a group of 10 teenagers smoked in 2001. 3. Calculate the...

**AP Calc. AB**

is it 57 m/s??

**AP Calc. AB**

If an arrow is shot upward on the moon with a velocity of 57 m/s its height (in meters) after t seconds is given by H= 57t-0.06t^2. With what velocity will the arrow hit the moon?

**AP Calc. AB**

Thanks Steve ur a life saver!!

**AP Calc. AB**

1.Which function is NOT continuous everywhere? A.y=(4x)/(x+1)^2 B.y=|x| C.y=(x)/(x^2+1) D.y=√(x^2+1) E.y=x^(2/3) 2.State the domain f(x)= √((x+6)) sinx 3. Let h(x) {(sin2x)/x, if x ≠ 0 {a, if x=0 find the value of a so that hi s continuousat x=0 a. it is sot ...

**US History**

What factors made New England so different from the middle and southern colonies? Consider such things as economics, environment, social make up, philosophy, and religion?

**US History**

Thank You!!!

**US History**

Why is the landing at Plymouth Rock seen as just as important as Jamestown, or more so, in the founding of our country?

**English**

Would just in this sentence be considered and adverb? Now when they were first made, the bears were covered with hair and had sharp claws. Would this be an example of adverb modifying a verb

**algebra**

Find the center and radius of the circle whose equation is 5x^2−6x+5y^2+8y−9=0.

**algebra**

Find the domain and range of: F(x)=sqrt(x)+16

**English**

What is the tone in When Grizzlies Walked Upright?

**Biology**

Is respiratory control more sensitive to small changes in arterial PO2 or in arterial PCO2?

**Biology - very urgent**

Is respiratory control more sensitive to small changes in arterial PO2 or in arterial PCO2?

**Marketing**

How would you classify Wal-Mart in terms of its position on the wheel of retailing versus that of an off-price retailer?

**Math**

At Lucy's Restaurant,1 3/4 a serving of tomato soup is cups. Lucy makes 63 cups of tomato soup each day. How many servings of tomato soup does she make?

**Chemistry**

Calculate the concentrations of all species in a 1.17 M Na2SO3 (sodium sulfite) solution. The ionization constants for sulfurous acid are Ka1 = 1.4× 10–2 and Ka2 = 6.3× 10–8. I found Na+ = 2.34 SO3^2- = 1.17 H2SO3 = 7.14 x10^-13 I can't find HSO3...

**Chemistry**

Phosphoric acid, H3PO4(aq), is a triprotic acid, meaning that one molecule of the acid has three acidic protons. Estimate the pH, and the concentrations of all species in a 0.200 M phosphoric acid solution. pKa1 = 2.16 pKa2 = 7.21 pKa3 = 12.32 Ok I haven't been able to ...

**analytic geometry**

the three vertices of a triangle are at A (-4,5), B(-5,3) and C (3,-4), show that the line joining the midpoint of the sides AC and BC is parallel and equal to one-half of AB . solve

**analytic geometry**

the three vertices of a triangle are at A (-4,5), B(-5,3) and C (3,-4), show that the line joining the midpoint of the sides AC and BC is parallel and equal to one-half of AB . solve

**science**

A comet is in an elliptical orbit around the Sun. Its closest approach to the Sun is a distance of 4.8 x10^10 m (inside the orbit of Mercury), at which point its speed is 9.1 x10^4 m/s. Its farthest distance from the Sun is far beyond the orbit of Pluto. What is its speed when...

**math**

what is the integral from 2 to 1 of 15sqrt(4x^2-3) dx

**science**

A 25 kg box is being pushed across the floor by a constant force ‹ 100, 0, 0 › N. The coefficient of kinetic friction for the table and box is 0.15. At t = 6.0 s the box is at location ‹ 14, 3, −4 › m, traveling with velocity ‹ 6, 0, 0 › m/s...

**Chemistry**

Fish breathe the dissolved air in water through their gills. Assuming the partial pressures of oxygen and nitrogen in the air are to be .20 atm and .80 atm respectively, calculate the mole fractions of oxygen and nitrogen in the air dissolved in water at 298 k. The ...

**geometry**

Ralph the monkey is looking down at a 31° angle from the top of a tree. There are bananas on the ground 12.4 ft from the base of the tree. If Ralph flies down from the tree at a diagonal path, shown in the diagram by x, what distance would he travel? Round to the nearest ...

**maths**

calculate the values of p and q Analytical geometry

**physics**

A moving object has a kinetic energy of 147 J and a momentum of 22.3 kg·m/s. a) Find the speed of the object. Answer in units of m/s

**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? can you show me what ...

**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?

**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?

**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?

**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?

**Algebra**

How can I solve 1/2x+1/x=-12?

**Chemistry**

. 0.1M Urea

**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?

**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.

**algebra**

FOR CA STUDENTS!!! 1. A 2. B 3. D 4. D 5. A

**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?

**algebra**

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

**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