Monday

February 8, 2016
Total # Posts: 986

**Precalculus**

I have been trying to verify the below identity. I have been at it for hours, can anyone please help? 1+ cos(theta)/Cos(theta) = tan^2(theta)/sec(theta)-1
*October 29, 2012*

**physics**

A 50 kg uniform ladder, 5.0 m long, is placed against a smooth wall at a height of h = 3.7 m. The base of the ladder rests on a rough horizontal surface whose coefficient of static friction is 0.40. An 80 kg block is suspended from the top rung of the ladder, just at the wall...
*October 29, 2012*

**Physics**

What force do the blades of a 4200 kg helicopter exert on the air when the helicopter is dropping at 23 m/s with speed decreasing at 3.7 m/s^2?
*October 26, 2012*

**Math**

What is the volume in cubic feet, of a box that is 3ft long, 8th wide, and 16ft high?
*October 22, 2012*

**Physics(please bobpursley)**

A girl coasts down a hill on a sled, reaching level ground at the bottom with a speed of 6.7 m/s. The coeﬃcient of kinetic friction between the sled’s runners and the hard, icy snow is 0.048, and the girl and sled together weigh 615N. The acceleration of gravity is...
*October 21, 2012*

**physics**

block A (mass 2.04kg) rests on a tabletop. It is connected by a horizontal cord passing over a light, frictionless pulley to a hanging block B (mass 3.00kg ). The coefficient of kinetic friction between block A and the tabletop is 0.215. After the blocks are released from ...
*October 11, 2012*

**Stats**

Calculate the expected value and standard deviation of X, the number of on the job accidents: Accidents 0,1 2 Probability .5, ?, .2 P(X=1) = E(x) = µx = Standard deviation =
*October 11, 2012*

**Stats**

Let Y be a random number between 0 and 1 produced by the idealized uniform random number generator with density curve pictured in the following figure: P(<Y<0.4) = P(0.4<Y<1) = P(0.3<Y<0.5)+
*October 11, 2012*

**Trigonomety question**

How do you find the exact value of Sin(13pi)?
*October 8, 2012*

**Chemistry**

A compound Contains 14.5g of magnesium and 3.5 g of oxygen. what the mass of oxygen in the compound ?
*October 5, 2012*

**Algebra**

How did you arrive at that answer?
*October 3, 2012*

**Algebra**

A bean sprout grows 3 inches in its first week, 2 inches in its second week, and 1.333 inches in its third week. If the sprout's growth follows this pattern, how much will the bean sprout have grown in its fourth week?
*October 3, 2012*

**science**

The universal wave equation states that v = fë, therefore wavelength is directly related to the speed of the wave. That means that if the frequency is increased, the speed is also increased and vice versa, as long as frequency is kept constant.
*October 3, 2012*

**math**

2x+x=72 3x=72 x=24 2x=48 The two lengths of rope are 24 and 48 inches
*October 3, 2012*

**Physics**

lololololol
*September 26, 2012*

**Physics**

mia you are so smart and beautiful
*September 26, 2012*

**Precalc/Trig**

wave is modeled by the function ... h(t) = 3cos(p/10)*t What is the period of the wave (T) *frequency (F) is defined as the number of cycles of the motion per second. What is the relationship between F and T? Find the wave height (H) which is the vertical distance between the ...
*September 26, 2012*

**math**

I agree with Ms. Sue, Sneha, and pete
*September 24, 2012*

**Physics**

A child’s toy consists of plastic attached to a spring. The spring is compressed against the floor a distance of 1.48 cm, and the toy is released. The acceleration of gravity is 9.8 m/s2 . If the toy has a mass of 109 g and rises to a maximum height of 58.7 cm, estimate ...
*September 19, 2012*

**Chemistry**

My question is 'what does the area under the curve represent?' it's a Maxwell-Boltzmann curve. My first idea was the number of particles but that's just what the y axis says and surely that wouldn't just mean under the curve. My second idea was to write ...
*September 16, 2012*

**physics**

, block A (mass 2.04)kg rests on a tabletop. It is connected by a horizontal cord passing over a light, frictionless pulley to a hanging block B (mass 3.00 )kg. The coefficient of kinetic friction between block A and the tabletop is 0.215. After the blocks are released from ...
*September 12, 2012*

**physics**

The highest George can suck water up a very long straw is 2.0m What is the lowest pressure he can maintain in his mouth? Express to two sig figs
*September 7, 2012*

**Statistics**

87
*September 4, 2012*

**Math**

Sam has a savings account that increased in value over 12 month period from $8765.00 to $9006.04. He made no deposits or withdrawals in that time. What annual percent interest did he receive for the 12 month period?
*August 20, 2012*

**math**

determine the domain and range for the function f(x,y)=Sq.Rt. 1-x*2-y*2
*August 14, 2012*

**physics**

An aircraft is flying at the speed of 354km/hr relative to the air is observed from the ground to have a velocity of 300km/hr in the north east direction. The wind is blowing from east. Find the speed of the wind and the direction to which the aircraft is heading.
*August 10, 2012*

**home**

how many grams of lead are in a 3/4 inch ball of lead
*July 6, 2012*

**physics**

What is the moment of inertia of a solid cylinder of radius R=0.9550m,thickness t= 0.015m, and total mass M= 3.565 kg?
*June 12, 2012*

**math**

36x3.14x8=?
*June 6, 2012*

**MATH**

5.3
*May 29, 2012*

**chemistry**

Current is applied to a molten mixture of CuF, ZnCl2, and AlBr3. What is produced at the cathode? a)F2 b)Al c)Cu d)Zn e)Cl2 f)Br2 What is produced at the anode? Same options as above.
*May 29, 2012*

**Geometry**

2.36 gallons. Correct?
*May 7, 2012*

**Geometry**

A flush tank on a toilet is rectangular with dimensions of 21 inches by 6.5 inches and contain water to a depth of 12 inches. How many gallons of water per flush will be saved if the depth of the water is reduced by one-third? 231 cubic inches per gallon)
*May 7, 2012*

**Chemistry**

The volume of a gas is 250 mL at 340.0 kPa pressure. What will the volume be when the pressure is reduced to 50.0 kPa, assuming the temperature remains constant?
*May 6, 2012*

**Calculus I**

At time t in seconds, a particle's distance s(t), in centimeters, from a point is given by s(t) = 4 + 3 sin t. What is the average velocity of the particle from t = pi/3 to t = 7pi/3?
*May 6, 2012*

**Calculus I**

At time t in seconds, a particle's distance s(t), in centimeters, from a point is given by s(t) = 4 + 3 sin t. What is the average velocity of the particle from t = ð/3 to t = 7ð/3?
*May 6, 2012*

**Wastewater treatment**

What is the molarity of 24.5 grams of sulfuric acid dissolved in a liter of water?
*May 4, 2012*

**Math**

what is $10.5002 rounded to the nearest cent, dime, and dollar. My work: cent: $10.50 dime: $10.50 dollar: $2:00 Did I do good?
*April 27, 2012*

**physics**

The balloon contains 0.30 {\rm mol} of helium starts at a pressure of 115 {\rm kPa} and rises to an altitude where the pressure is 55.0 {\rm kPa}, maintaining a constant 300 {\rm K} temperature. (A)By what factor does its volume increase? (B)How much work does the gas in the ...
*April 22, 2012*

**Physics**

I got like, 7431, is that correct? Because that seems rather large.
*April 13, 2012*

**Physics**

Find the speed of sound (in m/s) at -35°C at 1 atm pressure in dry air.
*April 13, 2012*

**Physics**

so do you not need the diameter for anything?
*April 12, 2012*

**Physics**

Rotating initially at 1800 rpm, a wheel with a diameter of 74.0 cm is brought to rest in 11.0 s. Calculate the magnitude of its angular acceleration in radians/second^2
*April 12, 2012*

**chemistry**

we have a bag that can hold up to 775 ml. we have baking soda and 6 molar of hydrochloric acid. how can we find out how much baking soda and acid we need so that when they react, the gas will fill the bag up just enough so that it wont pop
*April 10, 2012*

**what is the interest on $3,400.00 per year**

for twenty years
*March 30, 2012*

**Crime scene chemistry**

we dont know.
*March 28, 2012*

**physics**

A uniform electric field of magnitude 339 N/C is directed along the +y-axis. A 6.00 µC charge moves from the origin to the point (x, y) = (-40 cm, -33 cm).What is the change in potential energy associated with this charge ?
*March 28, 2012*

**math**

yes, excellent, that is correct, as well as the answer
*March 28, 2012*

**algebra**

1st part 69m @ X+5mph 2nd part 23m @ X so,69m/x+5 + 23m/x = 2hours 69/x+5 + 23/x = 2 LCD ==> 69(x)+ 23(x+5)= 2x(x+5) 69x+23x+115=2x^2+10x 92x+115=2x^2+10x 0=2x^2-82x-115 wont factor, use quadratic formula x=(-b}ã(b^2-4ac))/2a x=-(-82)}ã...
*March 28, 2012*

**Geometry**

volume of a sphere (4/3)(3.14)Radius cubed, so, 4/3*3.14*6*6*6 = 904 cubic feet of water, but, you only want it "half" full 904*1/2=452.39 cu. ft. of water
*March 28, 2012*

**trig**

100cos10=x 100sin10=y <x,y>
*March 19, 2012*

**stuck**

wouldnt it just be 16.0m/s + 5.36m/s. Because the car had to be traveling faster than the other to push it? I might be wrong though so don't think mine is perfect. What class is this for?
*March 15, 2012*

**physics**

A ball on the end of a string is revolving at a uniform rate in a vertical circle of radius 98.8 cm. If its speed is 4.60 m/s, and its mass is 0.345 kg, calculate the tension (in newtons) in the string when the ball is at the bottom of the path.
*March 12, 2012*

**walter**

A positive charge of 1.5x10^-8 C experiences a force of 0.025 N to the left in an electric field. What are the magnitude and direction of the field?
*March 8, 2012*

**physics**

A 0.180 kg baseball, traveling 32.0 m/s, strikes the catcher's mitt, which recoils 13.0 cm in bringing the ball to rest. What was the average force (in newtons) applied by the ball to the mitt?
*March 7, 2012*

**Calculus Find max and min and saddle**

Lucy I think you are wrong,what I got is much that I can't type ,mayb some social network or video call .
*February 28, 2012*

**math**

A customer is buying a $100 drill and two $15 drill bit sets. The customer uses a gift card worth $50 to pay for a portion of their bill. How much cash will the customer pay (before taxes)?
*February 27, 2012*

**Economics**

poop
*February 22, 2012*

**AP CHEMISTRY**

thanx very much!!!!!
*February 15, 2012*

**Geometry**

the answer is B. length of jane's garden is double the length of simon's garden
*February 15, 2012*

**chemistry**

A 141-mg sample was placed on a watch glass that weighed 9.203 g. What is the weight if the watch glass and sample in grams?
*February 2, 2012*

**Math**

Subtract: 7 gal 2 qt 1 pt – 5 gal 3 qt ½ pt I'm stuck plz help.
*January 26, 2012*

**Physics**

A water bed that is 1.5 m wide and 2.5 m long weighs 1055 N. Assuming the entire lower surface of the bed is in contact with the floor, what is the pressure the bed exerts on the floor? (Round to the first decimal point and don't forget units.
*December 19, 2011*

**Physics**

A cube of wood with a density of 0.780 g/cm3 is 10.0 cm on each side. When the cube is placed in water, what buoyant force acts on the wood? (ρw = 1.00 g/cm3) a. 5.00 N b. 6.40 N c. 7.65 N d. 7.65 x 10^3 N
*December 19, 2011*

**math**

a 41 inch ribbon was cut into five shorter ribbons of equal length how long was each shorter ribbon
*December 7, 2011*

**chemistry**

magnesium nitrate decompses in water and releases ammonia gas. If 355ml of ammonia is produced at STP, whit is the mass of Magnesim nitrate that reacted. Equation is Mg3N2+6H2O=3Mg(OH)2+2NH3
*December 1, 2011*

**chemistry**

The radius of an atom is about 10,000 times as large as its nucleus. If the atom were enlarged such that the radius of its nucleus was 1 inch, what would be the radius of the atom in meters? I need the formula to follow so that I can solve this problem.
*December 1, 2011*

**physics**

pinecone
*November 28, 2011*

**Math**

2%, am i right?
*November 2, 2011*

**Math**

The annual interest rate on an investment is 8%. What is the quarterly rate? (a) 1% (b)12% (c) 16% (d)2% (e)3% Can someone help me figure out the formula for finding out the quarterly rate?
*November 2, 2011*

**math**

Aldo invested his savings in two investment funds. The $24, 000that he invested in Fund A returned a 1% profit. The amount that he invested in Fund B returned a 5% profit. How much did he invest in Fund B, if both funds together returned a 2% profit?
*October 26, 2011*

**Science Math**

7. Calculate the difference in the lung volumes of a male athlete who is 62 inches tall and a female athlete who is 56 inches tall. Show your work. (2 points)
*October 14, 2011*

**anaheim**

a glacier moves with a speed of 54m/s. how many years wold it take for the glacier to move 0.65 km? assume there are 365 days in a year
*October 14, 2011*

**cost accounting**

D A
*October 14, 2011*

**EXP 105 Personal Dimensions of Education**

Write two to three paragraphs briefly summarizing the theory and discussing at least two of the “Seven Intelligences” that apply most closely to you, providing examples to illustrate your point.
*October 10, 2011*

**Science**

I am making an essay about the conditions of our water resources and the issues concerning our water. What is a good title for the essay?
*October 10, 2011*

**Physics**

An unmarked police car traveling a constant 80 is passed by a speeder traveling 145 .Precisely 2.50 after the speeder passes, the police officer steps on the accelerator; if the police car's acceleration is 1.80 , how much time passes before the police car overtakes the ...
*October 4, 2011*

**AP Chemistry**

I had this question: 3) A certain shell is known to have a total of 16 orbitals. Which shell is it? a) n = 4 b) n = 16 c) n = 8 d) n = 2 and the answer was a) n = 4.
*October 2, 2011*

**geometry**

Point T bisects RS. If R(-2,-5) and S(-14,-21), find the coordinates of point T.
*September 29, 2011*

**Physics 12th grade**

A farm tractor is pulling 2 pieces of equipment east, with each piece of equipment 25 north and south of the x axis. If it takes 50,000 N of force on each chain to keep the equipment moving, then what is the total force of the tractor in the x direction?
*September 26, 2011*

**Math**

For 31 hours of work you are paid $ 361.15. How much would you receive for 33 hours of work? (a) $ 372.80 (b) $ 384.45 (c) $ 42.65 (d) $ 11.65 (e) $ 384.54
*September 15, 2011*

**Math**

Choices are: (a) decimal (b) sum (c) vertically (d) horizontally (e) concentrically
*September 15, 2011*

**Math**

Like fractional notation, __________ notation is used to denote a part of a whole.
*September 15, 2011*

**Math**

When multiplying decimals, the decimal point in the product is placed so that the number of decimal places in the product is equal to the __________ of the number of decimal places in the factors. (a) product (b) sum (c) vertically (d) horizontally (e) and
*September 14, 2011*

**Math**

When writing decimals in words, write " __________ " for the decimal spot. (a) decimal (b) sum (c) vertically (d) horizontally (e) and
*September 14, 2011*

**Math**

Brand A grape juice sells at one pint for $1.65 and Brand B sells at 14 ounces for $ 1.44 . Which brand has the lower unit price? (one pint is equal to 16 ounces ) (a) Brand A (b) Brand B
*September 14, 2011*

**Math**

K thanks
*September 14, 2011*

**Math**

Sandy Sanders has an hourly wage of $ 15.00 and is paid time and one half for all overtime after 40 hours. Calculate Sandy’s gross pay for the week of August 13 for which she worked the following number of hours. Sunday: Monday: 8.5 Tuesday: 9.5 Wednesday: 6.25 Thursday: ...
*September 14, 2011*

**Math**

Ok thanks
*September 14, 2011*

**Math**

The list price of an item is $ 78.99 and the net price is $ 56.67 . Determine the amount of discount.
*September 14, 2011*

**Math**

Ok thanks
*September 13, 2011*

**Math**

The value of 25 coins, consisting of dimes and quarters, is $ 3.55. How many dimes are in the collection?
*September 13, 2011*

**Math**

Ok thanks
*September 13, 2011*

**Math**

John withdrew $ 500 out of his bank savings account. He spent $ 50 on a radio, and 3 / 5 of what remained on gifts for his friends. How much money did John spend on gifts for his friends?
*September 13, 2011*

**Math**

The value of 25 coins, consisting of dimes and quarters, is $ 3.55. How many dimes are in the collection?
*September 13, 2011*

**Math**

Round 0.000453 to the nearest thousandth.
*September 13, 2011*

**Math**

At 4 p.m., what part of a day has elapsed?
*September 13, 2011*

**Math**

Mrs. Hansen has 84 yards of material available to make school uniforms. Each uniform requires 3 / 4 yard of material. How many uniforms can be made?
*September 13, 2011*

**Math - Linear algebra**

Thank you, that was the answer I got too, but in a slightly different method, but I want to learn for how you figure this out, with this problem. I feel like you just you the same method but I am having a little problem with this one: "Suppose you want to make $5 using ...
*September 11, 2011*