Tuesday

February 21, 2017
Total # Posts: 2,590

**Calculus**

A street light is at the top of a 19 foot tall pole. A 6 foot tall woman walks away from the pole with a speed of 7 ft/sec along a straight path. How fast is the tip of her shadow moving when she is 30 feet from the base of the pole?

*April 3, 2012*

**AP CHEM**

When 0.03 moles of lead(II) nitrate are dissolved in enough water to make 266 milliliters of solution, what is the molar concentration of nitrate ions? Answer in units of M I already tried moles per liter and it says it is wrong.

*April 1, 2012*

**Chemistry**

Yeah I'm referring to the phase diagram and the Solid/Liquid line

*March 29, 2012*

**Chemistry**

I think the negative sign implies that the slope between S and L is negative so as you increase Pressure you will get a small T. But what formula did you use to find delta T.

*March 29, 2012*

**Fantel**

The heat of vaporization of water is 40.66 kJ/mol. Assuming sweat is 100% water, how much heat is removed from your body through the evaporation of 3.50 g of sweat?

*March 28, 2012*

**math**

hi if the second term of a sequence is root(2) and the seventh term is 8 what is the nth term equation(Geometric sequence) thanks

*March 26, 2012*

**statistics**

Elesha.. I don't understand your answers

*March 26, 2012*

**Math**

the volume of a rectangular prism is 256 cubic centimeters. What is the volume of a similar rectangular prism that has edge lengths one fourth as long as the edge lengths of the original prism?

*March 26, 2012*

**science**

a 2000 kg sedan is traveling west at 25m/s. How would the sedan's momentum change if it slowed down to 10 m/s?

*March 25, 2012*

**probability/binomial**

i'm having trouble with probability and the binomial thm, could i get a good website with problems

*March 24, 2012*

**Math**

I think they're all correct

*March 19, 2012*

**English 11**

1d 2a 3c 4 d

*March 12, 2012*

**alg2trig**

1-(1/a)/1-(1/a^2)

*March 11, 2012*

**physics**

A 1.1 kg hammer slams down on a nail at 5.0 m/s and bounces back at 1.0 m/s. If the impact lasts 1.0 ms, what average force is exerted on the nail?

*March 11, 2012*

**chemitry**

thanks

*March 9, 2012*

**chemitry**

I have a list of chemicals, how do i know if they are alkanes and alcohols

*March 9, 2012*

**Math**

Transform the equation by completing the square: y^2 + 2x - 6y - 7 = 0

*March 8, 2012*

**calculus**

Find a unit vector U such that the rate of change of f in the direction of U at the given point is maximum. point being (3,5,pi) I know hos to do this when given a direction but since im asked to ind the unit vector first it kinda throws me off. do i just use my point? like ...

*March 8, 2012*

**physics**

A high-speed sander has a disk 8.00 cm in radius that rotates about its axis at a constant rate of 1100 revolutions per minute. Determine the angular speed of the disk in radians per second.

*March 7, 2012*

**chemistry**

what are van der waals forces

*March 7, 2012*

**Physics**

Haha this is a trick question. Electricity is a hoax

*March 6, 2012*

**Chemistry**

is this answer correct? these form need to verify is these answers are correct. ty

*March 5, 2012*

**algebra**

M times 2/3 equals 1 - 13/15

*March 4, 2012*

**physics**

216000000

*March 4, 2012*

**math**

12 students wanted to go on a field trip. that was 3/4 of the class. how many students are in the class

*March 4, 2012*

**chemistry**

what is the difference between an inhibitor and a catalyst in a chemical process?

*March 1, 2012*

**physics**

A science museum has asked you to design a simple pendulum that will make 25.0 complete swings in 85.0 {\rm s}. How long should the pendulum be? in meters

*February 29, 2012*

**physics**

FFFFFFFFFFFFUUUUUUUUUUUUUU

*February 28, 2012*

**physics**

A 750.0 N man, carrying a 1.9 kg physics textbook, stands at the center of a frozen pond of radius 9.0 m. He is unable to get to the other side because of a lack of friction between his shoes and the ice. To overcome his difficulty, he throws his textbook horizontally at a ...

*February 27, 2012*

**physics**

A 750.0 N man, carrying a 1.9 kg physics textbook, stands at the center of a frozen pond of radius 9.0 m. He is unable to get to the other side because of a lack of friction between his shoes and the ice. To overcome his difficulty, he throws his textbook horizontally at a ...

*February 26, 2012*

**physics**

A car is sitting at the top of an inclined plane, which is 5.2 meters long and meets the horizontal at an angle of 12 degrees. The cart is then allowed to roll to the bottom of the incline. What will be the velocity of the cart at the bottom of the incline. (4.61m/s) Please ...

*February 25, 2012*

**chemistryhelp**

for example will AlCl3 conduct less electricity than NaCl

*February 24, 2012*

**chemistryhelp**

i also had a question on conductivity, if i have an ionic solution with 2 salts at same mass will the one with least molecular mass conduct more electricity (bc there are more ions)

*February 24, 2012*

**chemistryhelp**

but can i use other salts?

*February 24, 2012*

**chemistryhelp**

if i made a simple circuit with an NaCl in between is that similar to what the electrolyte in a battery does so does that mean that i can put NaCl in substitute of whatever is currently in the battery

*February 24, 2012*

**chemistryhelp**

also I was researching and I was wondering what an ionic current was

*February 24, 2012*

**chemistryhelp**

can the electrolyte be a salt (NaCl of KCl)

*February 24, 2012*

**chemistryhelp**

so it transfers the electrons (based on what I know)

*February 24, 2012*

**chemistryhelp**

what does the electrolyte in batteries do?

*February 24, 2012*

**highschool bio**

Cells are specialized in structure to match their function. Compare cell specialization in gametes with other examples of cell specialization.

*February 22, 2012*

**Physics**

A child pushes a merry go-round from rest to a final angular speed of 0.78 rev/s with constant angular acceleration. In doing so, the child pushes the merry-go-round 1.6 revolutions. What is the angular acceleration of the merry go-round? v=d/t .78rev/s = 1.6 rev / t t= 1.6 ...

*February 21, 2012*

**physics**

A 67.7 kg person jumps from rest off a 3.11 m-high tower straight down into the water. Neglect air resistance during the descent. She comes to rest 1.04 m under the surface of the water. Determine the magnitude of the average force that the water exerts on the diver. This ...

*February 20, 2012*

**physics**

A 690 kg elevator starts from rest. It moves upward for 2.56 s with constant acceleration until it reaches its cruising speed, 1.84 m/s. What is the average power of the elevator motor during this period?, What is the power of the elevator motor during an upward cruise with ...

*February 19, 2012*

**statistics**

Suppose that the weights of airline passenger bags are normally distributed with a mean of 48.08 pounds and a standard deviation of 3.13 pounds. A)Let X represent the weight of a randomly selected bag. For what value of c is P(E(X) - c < X < E(X) + c)=0.84? Give your ...

*February 19, 2012*

**physics**

On a frozen pond, a 13.2 kg sled is given a kick that imparts to it an initial speed of v0 = 2.48 m/s. The coefficient of kinetic friction between sled and ice is μk = 0.123. Use the work kinetic energy theorem to find the distance the sled moves before coming to rest.

*February 18, 2012*

**Math ratios**

The ratio of cars to vans in a parking lot was 5 to 2. There were 28 cars and vans in the parking lot. How many cars were in the parking lot? How many vans were in the parking lot?

*February 18, 2012*

**Biology**

Sure.

*February 17, 2012*

**physics**

A wave traveling in the + x direction has an amplitude of 0.35 m, a speed of 5.2 m/s, and a frequency of 14 Hz. Determine: 3.1.the wavelength, (2) 3.2.the wave number, (2) 3.3the angular velocity, (2) 3.4. the equation of the wave

*February 16, 2012*

**emergency physics**

The 2nd harmonic of a string of length 40cm and linear mass density 1.11g.m has the same frequency as the 5th resonance mode of a closed pipe of length 1.4m. Find the tension in the string. use 340 for speed of sound

*February 15, 2012*

**Math**

33.4 because it takes into consideration probability, you have to look at the number and depending on weether it is even or odd you either increase or decrease

*February 15, 2012*

**physics**

The rider sees a traffic queue ahead. He applies the brakes and reduces the speed of the motorbike from 18 m/s to 3 m/s. Use the equation in the box to calculate the kinetic energy lost by the motorbike. 1 over 2× mass × speed

*February 15, 2012*

**Math**

An airplane leaves the airport and flies due west 170 miles and then 240 miles in the direction 200°30'. Assuming the earth is flat, how far is the plane from the airport at this time( to the nearest mile)?

*February 14, 2012*

**physics**

A car travels at a constant speed around a circular track whose radius is 2.60 km. The car goes once around the track in 344 s. What is the magnitude of the centripetal acceleration of the car?

*February 13, 2012*

**networking**

In an analog cellular structure, what is needed to establish a valid authentication?

*February 13, 2012*

**Physics**

If a total mass of 11.1 kg falls 5.23 m and all of the mechanical energy is converted to internal energy, by how much will the internal energy of the water increase? The acceleration of gravity is 9.81 m/s 2 . Assume no energy is transferred as heat out of the vessel to the ...

*February 12, 2012*

**math word problem**

lexi and maria had $250.oo altogether. After lexi spent 2/5 of her money and Maria spent $40.00 they had the same amount of money left.How much money did lexi have in the beginning?

*February 12, 2012*

**Mathematics**

OPQRS is a right pyramid whose base is a square of sides 12cm each. Given that the slant height of the pyramid is 15cm. Find the height of the pyramid, the volume of the pyramid, and the total surface area of the pyramid by first drawing the net of the pyramid.

*February 11, 2012*

**Physics**

A rocket of mass 4.5 e5 kg is in flight. Its thrust is directed at an angle of 58.5° above the horizontal and has a magnitude of 7.50e6 N. Find the magnitude and direction of the rockets acceleration. Give the direction as an angle above the horizonal.

*February 10, 2012*

**trigonometry**

the bases of a trapezoid are 22 and 12 respectively. The angles at the extremities of one base are 65 degree and 40 degree respectively find the two legs. Answer using law of sines pls

*February 10, 2012*

**Mathematics**

The mass of Aravin to the mass of Bob is in the ratio 17 : 13. If the difference in their masses is 12 kg, find their combined mass.

*February 8, 2012*

**math**

a rope 60m long and 5cm in diameter is coiled tightly. Estimate, correct to one significant figure, the radius of the 'circle' formed. ( please could we have working out).

*February 7, 2012*

**physics**

At a time t after being projected from the ground, a projectile is displaced x units horizontally and y units vertically above its point of projection. (Use any variable or symbol stated above along with the following as necessary: g.) (a) What are the horizontal and vertical ...

*February 6, 2012*

**physics**

a box slides down a frictionless hill. the spring stops it. when the box stops how much has the spring compressed. the hill is 5m high, the mas of the box is 20 kg, and the spring constant is 350 n/m

*February 5, 2012*

**physics**

A person throws a 2.5 lb stone into the air with an initial upward speed of 15 ft/s. Make a free-body diagram for this stone (a) after it is free of the person’s hand and is traveling upward, (b) at its highest point, (c) when it is traveling down ward, and (d) while it ...

*February 1, 2012*

**math**

The diagram shows a shape, all the corners are right angles, all the measurements are in cm explain why (x+4) (x +5) - 6 15

*January 31, 2012*

**chemistry**

Suppose that 1.78 x 10^3 kg of Fe are obtained from a 5.80 x 10^3 kg sample of Fe2O3. Assuming that the reaction goes to completion, what is the percent purity of Fe2O3 in the original sample?

*January 31, 2012*

**Measurement:: Metric Units**

A classroom table is 1 m wide and 1.75 m long. How many 39 cm wide chairs can fit around the table?

*January 31, 2012*

**math**

Our big black cat had some kittens, one was white one was black and one was tabby. How many cats lived in our house?

*January 30, 2012*

**chemistry**

correct answer is: -5133.3-[(8x-393.5)+9(-241.8)] = 190.9 since it is an enthalpy of formation, the value has to be negative, thus the correct answer is -190.9

*January 29, 2012*

**physics**

A 0.25 kg cube of iron is heated and its temperature rises from 23.0 C to 45.0 C. How much heat entered the cube in Joules and in Calories?

*January 26, 2012*

**physics**

anyway can you help me solve this problem please

*January 19, 2012*

**physics**

yes i did pay but they are not going to help

*January 19, 2012*

**physics**

yea i put in masterphyics hw and it said its wrong i did it 3 times this question is driving me crazy

*January 19, 2012*

**physics**

A helicopter 7.60m above the ground and descending at 3.90m/s drops a package from rest (relative to the helicopter). We have chosen the positive positive direction to be upward. The package falls freely. part A- Just as it hits the ground, find the velocity of the package ...

*January 19, 2012*

**math**

Scott uses three 14 gallon tanks of gas a month. What is the average number of gallons he uses daily in a 30 day month? Give your answer to the nearest half gallon

*January 19, 2012*

**physics help**

well i square rooted 164.17 and gave me 12.8128 then i put - 12.8 and it gave me a wrong anwser for my hw problem

*January 19, 2012*

**physics help**

i didn't put 7.60m and 3.90m/s in the question problem

*January 19, 2012*

**physics help**

for A is it 164.17 b. would be a upward direction

*January 19, 2012*

**physics help**

A helicopter 7.60 above the ground and descending at 3.90 drops a package from rest (relative to the helicopter). We have chosen the positive positive direction to be upward. The package falls freely. A)Just as it hits the ground, find the velocity of the package relative to ...

*January 19, 2012*

**Math**

x-5 MOST research shows x-5 though i think it is a sentence......not sure about answer so if you think its wrong it probably is wrong

*January 17, 2012*

**Math**

Simplify 2x(x+3) Is it suppose to be 2x^2+6 or 2x^2+6x?

*January 17, 2012*

**arithmetic**

find the cost of 100grams of rice per 1/2 a kilogram

*January 16, 2012*

**geometry**

The graphs y=2x+1 and 2y+x=2 contain 2 sides of a rectangle.if 1 vertex of the rectangle has coordinates (6,3), draw the rectangle.

*January 11, 2012*

**statistics**

Mean class scored 74 w/ standard deviation of 4.3. What is range of scores for 68% of class?

*January 10, 2012*

**trigonometry**

okay i understand what u r saying...i think LOL we have a right triangle A= right verticle B= bottom horizontal (called the base when i was in school.thousand years back.) and C= adjascent line copleting triangle. A is on left, so we are on the same pagefrom the bottom of A ...

*January 7, 2012*

**trigonometry**

plz, forgive me, it has bee a while since i have worked with angle and terminology. i meant having a right angle triangle (the bottom or lowest horizontal line being the BASE line , the 90 degree line being the right angle. say the horizontal line is .5 inches the right angle ...

*January 7, 2012*

**trigonometry**

what is th decimal equiavalent of three degrees of a 90 degree angle with a .1666 long base

*January 7, 2012*

**physics**

An oxygen molecule consists of two oxygen atoms whose total mass is 5.3 x 10-26 kg and whose moment of inertia about an axis perpendicular to the line joining the two atoms, midway between them, is 1.82 × 10-46 kg·m2. From these data, estimate the effective ...

*January 2, 2012*

**physics**

A wheel of diameter 28.0 cm is constrained to rotate in the xy plane, about the z axis, which passes through its center. A force = (-38.0 + 39.0 ) N acts at a point on the edge of the wheel that lies exactly on the x axis at a particular instant. What is the torque about the ...

*January 2, 2012*

**Math grade 12**

10b-b+1

*January 1, 2012*

**math**

72 tires are changed between a small and large truck over 8 weeks. The large truck has 3 times as many tires as the small truck. How many tires does the small truck have?

*December 21, 2011*

**Pre-Cal**

find the value of the function k(p/q)

*December 16, 2011*

**Electric Power Tools**

I need help with my test, I don't know if they are all right or not. I answered the questions to the best of my ability. My answers are marked with an *. 1. What is the typical no-load speed of a high-speed drill? A. 1,000 rpm *B. 2,500 rpm C. 3,000 rpm D. 3,500 rpm 2. Why...

*December 15, 2011*

**English**

Do I need a comma in this sentence or can it be improved on? This dream signifies Gabriel’s hope for Roy to follow in his footsteps and become a religious figure like him.

*December 15, 2011*

**statistics**

If 20% of the people in a community use the emergency room at a hospital in one year, find the probabilities for a sample of 10 people, a.At the most three use the emergency room. b.Exactly three use the emergency room c.At least five use the emergency room.

*December 13, 2011*

**english**

Should i use the word by, of, as..in this sentence? John doesn’t know who or what to believe, for he has never experienced the cruelties by white people, like his father had.

*December 13, 2011*

**english**

Is this properly written? Ichiro Yamada, a no-no boy, struggles with an identity crisis as he returns home to Seattle after World War II.

*December 12, 2011*

**literature**

Full Powers

*December 12, 2011*

**literature**

"The poem of the Full Powers by Pablo Neruda" I need to know what is the poem about? I already read this poem but i don't really understand it :(

*December 12, 2011*