Monday

July 6, 2015

July 6, 2015

Total # Posts: 932

**physics**

A boulder is raised above the ground so that the gravitational potential energy relative to the ground is 360 J. Then it is dropped. What is its kinetic energy just before it hits the ground?
*March 11, 2013*

**physics**

Calculate the work done when a 18 N force pushes a cart 2.5 m.
*March 11, 2013*

**Chemistry**

What is the pH of a 0.77M solution of methylamin at 25 degree C? CH3NH2, Kb= 4.4X10-4? How do I set this up to get the answer?
*March 7, 2013*

**maths**

find the first 3 terms in the expansion of (x+4)(1+3x)^-2 as a series in ascending powers. I expanded the second bracket using binomial expansion and got 1 -6x +27x^2 -108x^3 how do I combine (x+4) with the expansion? Any help would be appreciated.
*March 3, 2013*

**algebra**

X= log base 3 1/27
*March 1, 2013*

**Science**

What is the momentum of a 50 kg carton that slides at 2 m/s across an icy surface? The sliding carton skids onto a rough surface and stops in 3 s. Calculate the force of friction it encounters.
*February 26, 2013*

**science**

A car with a mass of 700 kg moves at 18 m/s. What braking force is needed to bring the car to a halt in 10 s?
*February 25, 2013*

**physics**

In terms of impulse and momentum, why are airbags in automobiles a good idea? A.)Airbags actually do not help if a car is in an accident. B.)They increase the amount of force involved in a collision. C.)They decrease the amount of time for a collision to happen. D.)They ...
*February 25, 2013*

**Math**

sorry i meant u too jj
*February 21, 2013*

**Math**

you too knight
*February 21, 2013*

**Math**

The eggplant ave. bus passes max's house every 8 mins. the cabb creek bus passes it every 12 mins. the last they passed by together was at 9:00 am. when will it happen again
*February 21, 2013*

**Algerbra**

HELP!!!!!!! I have to find a rule for the following in and out. Input: 1,2,3,4 Output: 3,9,18,30
*February 19, 2013*

**Chemistry**

Chromatography relies on the differences in polarity between the compound, the mobile phase and the stationary phase. In your own words explain how polar and non-polar compounds can be separated using cellulose paper and petroleum ether. I have no idea
*February 13, 2013*

**physics**

I know this seems like a silly question but our professor said we should be getting a very small value that will not even make a substantial difference. It is a poorly thought out problem. Yes y/x = 13/125. That's all I can really help with. Sorry :( Thank you for your ...
*February 7, 2013*

**physics**

If the car has a mass of 0.4 kg, the ratio of height to width of the ramp is 13/125, the initial displacement is 1.9 m, and the change in momentum is 0.87 kg*m/s, how far will it coast back up the ramp before changing directions? tinypic(dot)com(slant)r(slant)10dunx3/7 I get ....
*February 7, 2013*

**physics**

A 52.5g super ball traveling at 28.0m/s bounces off a brick wall and rebounds at 18.5m/s. A high speed camera records this event. If the ball is in contact with the wall for 4.10ms, what is the magnitude of the average acceleration of the ball during this time interval?
*February 4, 2013*

**physics**

A car starts from rest and travels for 6.0s with a uniform acceleration of 2.7m/s ^2. The driver then applies the brakes, causing a uniform acceleration of -2.0m/s^2. If the brakes are applied for 2.0s, determine each of the following. a.) how fast is the car going at the end ...
*February 4, 2013*

**physics**

A person driving her car at 56km/hr approaches an intersection just as the traffic light turns yellow. She knows that the yellow light lasts only 20.s before turning to red, and she is 30m away from the near side of the intersection. The intersection is 15m wide. Her car's...
*February 4, 2013*

**physics**

In a test run, a certain car accelerates uniformly from zero to 17 m/s in 2.95s. a.) what is the magnitude of the car's acceleration? b.) how long does it take the car to change it's speed from 8.5m/s to 17m/s? c.) will doubling the time always double the change in speed?
*February 3, 2013*

**physics**

The cheetah can reach a top speed of 114km/h (71mi/h). While chasing its prey in a short sprint, a cheetah starts from rest and runs 50m in a straight line reaching a final speed of 91 km/h. a.) Determine the cheetah's average acceleration during the short sprint. b.) Find...
*February 3, 2013*

**Physics?**

the total mass-energy of one pound of anything is about how many joules
*January 31, 2013*

**physics**

A hiker starts at his camp and moves the following distances while exploring his surroundings: 70.0m north, 2.75 x 10^2m east, 130m at an angle 30.0 degrees north of east, and 1.50 x 10^2m south. a.) find his resultant displacement from camp. (take east as the positive x-...
*January 30, 2013*

**physics**

For 3 vectors, find the magnitude and direction of the vector D=A-B+3C. A of length 6.2 and pointing 52 degrees up from the negative x-axis B of length 6.6 and pointing 27 degrees up from the positive x-axis C of length 2.8 and pointing 57 degrees down from the positive x-axis...
*January 30, 2013*

**Math**

Test Axioms, What are the diagonals of a rectangle?
*January 28, 2013*

**Math**

negative exponents 16^-3/4?
*January 28, 2013*

**Math**

Rational exponents 8^2/3?
*January 28, 2013*

**physics**

A force Farrowbold1 of magnitude 5.00 units acts on an object at the origin in a direction θ = 34.0° above the positive x-axis. (See the figure below.) A second force Farrowbold2 of magnitude 5.00 units acts on the object in the direction of the positive y-axis. Find ...
*January 28, 2013*

**physics**

A man in a maze makes 3 consecutive displacements. His first displacement is 5.40m westward, and the second is 18.0m northward. At the end of his displacement he is back to where he started. Use the graphical method to find the magnitude and direction of his third displacement.
*January 28, 2013*

**Physics**

A baseball is dropped from a tall building and takes 4.1 seconds to hit the ground. From what height was the ball dropped?
*January 27, 2013*

**Precalculus**

I asked this yesterday but I was told my answer was incorrect by my professor. ln x^5 - ln x^2 = 3 solve for the unknown. I have reviewed my Log laws but yet I still cannot figure out what the answers are. The question asks for me to write all answers as a comma separated list...
*January 24, 2013*

**math**

how do you make a model for 1/3 times 18
*January 23, 2013*

**Trigonometry**

Thank you STEVE!!!!! Suppose that Cos (theta) = 1/square root 2 if 0<equal to theta , pi/2 then sin(theta) = tan (theta) = If 3pi/2 less than equal to theta , 2pi then sin(theta) = tan (theta) = I know the trig functions but I feel like I am missing something here. cos (...
*January 23, 2013*

**Logarithms**

lnx^5 - lnx^2 = 3 solve for the unknowns as a list. I tried using my calculator but apparently my answer is opposite ends of the universe
*January 23, 2013*

**chemistry**

how to calculate the mass of hydrogen in 150.0 g of ethene
*January 22, 2013*

**statistics/probability**

The supply office for a large construction firm has three welding units of Brand A and three welding units that are not Brand A in stock. If a welding unit is requested, the probability is .7 that the request will be for Brand A. Find the probability that exactly one of the ...
*January 14, 2013*

**trigonometry**

14. Solve sin 2x + sin x = 0 for 0 ≤ x ≤ 2π. 21. Write 2sin37°sin26° as a sum (or difference).
*January 1, 2013*

**physics**

moving car runs into stationary car, (against a wall)car does not move, however, the wall push back cancelling the force. Explain Newton's law that apply. Thanks, George
*December 22, 2012*

**algebra**

The sum of two numbers is 56. the larger number is 7 less than 3 times the smaller number. Find the smaller number.
*December 19, 2012*

**Pre-Calculus**

Thank You!
*November 18, 2012*

**Pre-Calculus**

Convert the equation y=5 to polar form.
*November 18, 2012*

**engineering**

a bolt located 50mm from the center of an auto wheel is tightened by the couple shown for .10 seconds. determine the resulting angular velocity of the wheel if the wheel has a radius of gyration of 250 mm and a mass of 19 kilograms
*November 17, 2012*

**Math**

Michaels car has a 18.0 gallon tank. If the tank has 5.5 gallons what fraction of the tank is full?
*November 14, 2012*

**Precalc**

Prove or disprove the following identity. cos(-x) - sin(-x) = cos(x) + sin(x)
*November 13, 2012*

**Precalculus**

rewrite the following expression as an algebraic expression in x: cos(arcsin x) I have made X to be X/1 but from there I am lost.
*November 12, 2012*

**Precalculus**

what is the arccos(2)? I have tried to use the unit circle but I do not understand this :/.
*November 12, 2012*

**Math**

5p+2q=3 7p+2q=11
*November 7, 2012*

**ENGLISH LIT**

The theme of the book "Tolstoy" the death of ivan ilyich. i read the book but i don't get the theme.
*November 6, 2012*

**Social Studies**

Yes, Here are my answers, please check them. 1. C - many different goods or services for sale in a market 2. B - lower prices and more choices for buyers. 3. D $199 4. C -price 5. A - a clearance sale
*November 2, 2012*

**Social Studies**

I am having a hard time with economics - we just started in my social studies class. Can I have help with my homework, please? 1. What phrase best defines competition? (1 point) just one main buyer of a good or service just one main seller of a good or service many different ...
*November 2, 2012*

**Math**

Thank you.
*November 1, 2012*

**Math**

After a reflection over the x-axis I have to find the coordinates of A1, B1, C1 I am having trouble with b1. A(1,4) B(3,-2) C(4,2) The reflection should be: A1 should be (1,-4) B1 ?????? C1 should be (4,-2) Can younhelp with the b1 coordinates and check my other coordinates too?
*November 1, 2012*

**psych**

Alfred Binet's work is associated with intelligence testing visual perception psychopathology comparative psychology classical conditioning
*November 1, 2012*

**Precalculus Follow Up 2**

Oh now I see your point. I am sorry I should have stated this before. How do I verify that tan^2(theta)/Sec(theta)-1 is somehow the same as 1+cos(theta)/Cos(Theta)?
*October 29, 2012*

**Precalculus Follow Up**

1+ cos(theta)/Cos(theta) = tan^2(theta)/sec(theta)-1 I am having trouble understanding how this is verified by the previous answer. I am sorry I just want to understand this because I didn't see a tan^2 anywhere :/. Step by step how did you verify the above identity? Please?
*October 29, 2012*

**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*

**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*

**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*