Tuesday

September 16, 2014

September 16, 2014

Total # Posts: 225

**chemistry**

Nitrogen-13 has a half-life of 10 minutes. Given a starting mass of 2.00 g of nitrogen-13, how many grams will remain at the end of 30 minutes?
*June 19, 2012*

**chemistry**

What is the molarity of the solution produced when 14.1 grams of ammonia is dissolved in sufficient water to prepare .100 liters of solution?
*May 22, 2012*

**calculus**

yes, i pretty sure i got it as my answer mathes the back of the book
*April 23, 2012*

**calculus,1**

we got a few examples in class but not understanding it at all
*April 23, 2012*

**calculus**

Can someone please show steps as I am having a hard time understanding. The position (in meters) of a particle is modeled by y=x^3-12.5x^2+51x-67.5, where xis in seconds. Find the max, min and point(s) of inflection.
*April 23, 2012*

**calculus,PSS**

help
*April 23, 2012*

**calculus**

This is just for study for exam coming up and says it could be worth up to 12 marks. Not understanding vry well the two
*April 23, 2012*

**calculus**

The position (in meters) of a particle is modeled by y=x^3-12.5x^2+51x-67.5, where xis in seconds. Find the max, min and point(s) of inflection.
*April 23, 2012*

**calculus**

A balloon is being filled at a rate of 4000 cm^3/min. How fast is the surface area of the ballon increasing when the radius is 125 cm? V=4/3pir^3, SA=4pir^2
*April 23, 2012*

**physics**

A certain dog whistle operates at 23.5 kHz, while another (brand X) operates at an unknown frequency. If neither whistle can be heard by humans when played separately, but a shrill whine of frequency 9200 Hz occurs when they are played simultaneously, estimate the operating ...
*April 23, 2012*

**Physics (Energy and Momentum)**

You are given V and are solving for dM/dt what do you set it equal to?
*April 17, 2012*

**physics**

what is the wave equation?
*April 16, 2012*

**physics**

FM radio signals are electromagnetic waves transmitted between frequencies of 88 MHz and 107 MHz. Find the range of wavelengths for these signals. largest___m smallest___m
*April 16, 2012*

**calculus**

Use Newtons method to find the roots of the equation 1/x=1+x^3
*April 4, 2012*

**Algebra 2**

Hi I need help. Can you show me how to solve this problem? Radical Inequalities. -2 + square root 9-5x greater than or equal to 6
*April 3, 2012*

**trig**

Find the other endpoint of the line segment with the given endpoint and mid point. 1. Endpoint:(-1, 9), midpoint: (-9, -10) 2. Endpoint: (2, 5), midpoint: (5, 1) 3. Endpoint:(9, -10), midpoint: (4, 8)
*March 28, 2012*

**Math**

Find the discriminant. Tell which conic section the graph will be. 3x^2 + 12 xy + 9y^2 + 7x -2y - 100
*March 11, 2012*

**managerial economics**

Qd=15.0-0.2P where Qd is annual quantity demanded in millions of units and P is the wholesale price. Incurred cost of $60 million. Production cost is $5/unit. (1) what is wholesale price, (2) production annually, (3) annual profit? Given this is a monopoly with an expiring ...
*February 29, 2012*

**trig**

does sec(x)tan(x)*tan(x)=[sec(x)(tan^2)x]
*February 23, 2012*

**chemistry**

what are three common ores from which copper can be extracted
*February 22, 2012*

**geometry**

How tall is a tower if it casts a shadow 65 ft long at the same time that a building 160 ft tall casts a shadow 130 ft long?
*February 16, 2012*

**Algebra**

How do you solve: (2x+1)(x-4)=0
*February 1, 2012*

**Language**

thank you
*January 30, 2012*

**Language **

3 disadvantages for town crying
*January 30, 2012*

**chemistry**

A solution was made by dissolving 10.0g of a nonvolatile nonelectrolyte compound in 100.0g of water froze at -0.93C. What is the approximate molecular weight of the substance. (for water..kf=1.86C/m) (m is molality)
*December 12, 2011*

**chemistry**

D=[mol.wt*P)/(R*T) D=(29.0 g/mol*0.97atm)/[(0.0821 atm*L/mol*K)*(303.15 K)] =1.13 g/L
*December 12, 2011*

**calculus**

Given f''(x)=5x−6 and f'(−3)=−6 and f(−3)=2. find f'(x) and f(1)
*November 19, 2011*

**physics**

A missile's trajectory takes it to a maximum altitude of 1300Km. If its launch speed is 5.9 Km/s, how fast is it moving at the peak of its trajectory? answer is in Km
*October 20, 2011*

**Physics.. please help!!!!!**

The third question is wrong...
*October 20, 2011*

**physics**

2.16km
*September 17, 2011*

**Math Help**

700-284=?
*September 13, 2011*

**Physics**

A frog in a hemispherical bowl, as shown below, just floats in a fluid with a density of 1.26*10e3 kg/m3. If the bowl has a radius of 6.16 cm and negligible mass, what is the mass of the frog?
*June 28, 2011*

**business**

Specialization
*April 20, 2011*

**social studies**

idk
*March 24, 2011*

**social studies**

vgvg,c
*March 24, 2011*

**social studies**

describe 2 details about the life of the Incas
*March 19, 2011*

**math**

Jeff is thinking of a function machine.He says that the output is 5 when the input is 4.What are two different rules that he could be thinking of.
*March 10, 2011*

**physics**

train is approaching the station at a speed of 20m.s sounds a 220 hz horn. What frequency does an observer on the station platform hear
*February 28, 2011*

**physics**

What do we know? r=6.38x10^6m T=1 day=86,400s Part A: T=2(pi)r/V ==> V=2(pi)r/T a=V^2/r (Plug & chug) Part B: Now, what do we know? Only T=1 day=86,400s. We no longer know r. Latitude we'll say is represented by "l". So r(l) = r cos l Once you find that radius...
*February 23, 2011*

**ESSAY NEED HELP PLEASE**

I would help but I'm working on one now
*January 24, 2011*

**Physics**

A car is approach a corner too fast and locks up the brakes at point A and holds them on for 12.5 M to point B. The car then moves from point B at a constant speed and does into the corner. At Point C because the car is still going to fast it goes out of control and leave the ...
*January 20, 2011*

**chemistry**

What products are formed when sucrose is heated in an aqueous sulfuric acid solution? What role does the acid play?
*January 16, 2011*

**math**

HELP ME!!! One of your friends missed the class on scientific notation. Describe how you would explain to your friend what it means for a number to be in scientific notation and how to convert a number from standard form to scientific notation.
*January 10, 2011*

**math**

its =
*January 10, 2011*

**math**

|60|___|-60| < > =
*January 10, 2011*

**physics**

4ooN per second
*December 15, 2010*

**calculus**

Let R be the region in the first quadrant bounded by the graphs of y=e^-x, y=1/2x+1, and x=2. Then find the volume of the solid when R is revolved about each of the following lines... the x axis, y=-1, y=2, the y axis, x=-1, and x=3.
*December 15, 2010*

**Chem**

H2SO4(aq) + Ba(NO3)2(aq) = BaSO4(s) + 2HNO3(aq) overall heat gen by reaction answer is supposed to be -659.3 but I keep coming up with something else.
*December 14, 2010*

**Math 8th grade**

.02(2X-3)-0.03(3x(.2)=-.02
*December 12, 2010*

**Calculus**

I got x=10/3 and x=6
*November 16, 2010*

**Calculus**

Find the x-coordinates of all points on the graph of y = x^3 - 4x^2 + 5x at which the tangent line is parallel to 2y - 10x - 7 = 0
*November 16, 2010*

**Calculus**

Thanks
*November 16, 2010*

**Calculus**

Find the x-coordinates of all points on the graph of y=x^3 - 4x^2 + 5x at which the tangent line is horizontal.
*November 16, 2010*

**The Crucible Crossword Puzzle question **

Bitter
*October 30, 2010*

**physics grade 11**

A 4.3 kg bucket of water is raised from a well by a rope. The acceleration of gravity is 9.8 m/s2 . If the upward acceleration of the bucket is 4.6 m/s2, find the force exerted by the rope on the bucket. Answer in units of N. I'm almost sure the answer requires me to use ...
*October 17, 2010*

**physics grade 11**

A 4.3 kg bucket of water is raised from a well by a rope. The acceleration of gravity is 9.8 m/s2 . If the upward acceleration of the bucket is 4.6 m/s2, find the force exerted by the rope on the bucket. Answer in units of N. I'm almost sure the answer requires me to use ...
*October 17, 2010*

**physics**

Why do we not need to convert N into kg?
*October 13, 2010*

**Chemistry**

How many milliliters of 0.230 M Na2S2O3 solution are needed to titrate 2.349 g of I2 according to the equation below? I2(aq)+2S2O3^2-(aq)->S4O6^2-(aq)+2I^1-(aq)
*October 6, 2010*

**Chemistry**

I have the same question and that's all the information that it gives
*September 28, 2010*

**biology**

Are all mixtures solutions? Are all solutions mixtures? Give an example.
*September 9, 2010*

**Fundamentals of Cost Analysis (Economic Analysis)**

1431926
*August 19, 2010*

**Chemistry**

It is difficult to type these but I'll do my best. This is the first question and I just don't get it. My professor is out of the country so any help would be appreciated. Give the IUPAC name for each of the following alkanes: CH3 I a. CH3--CH--CH2--CH2--CH3 b. CH3 CH3...
*July 20, 2010*

**Chemistry**

This is the first in a series of hw pages. If anyone would be able to help me with this one I think I would be able to complete the other 20 hw questions I have. Thanks to anyone that helps. For each definition, find a corresponding term from the following list: alkane,alkene...
*July 20, 2010*

**Physics**

An electromagnetic wave has an electric field strength of 145 V/m at a point P in space at time t. A parallel-plate capacitor whose plates have area 0.109 m2 has a uniform electric field between its plates with the same energy density as the answer to part a. What is the ...
*July 1, 2010*

**Physics**

A solenoid is 10.0 cm long, has a radius of 0.500 cm and has 8000 equally spaced loops. What angular frequency needs to drive this inductor so that it has a reactance of 6.000e+3 ohms?
*June 24, 2010*

**com150**

I can't find anything on the internet to support my subject in my expository essay can anyone help my topic is "Explain the practical value of studying chemistry". thanks
*May 23, 2010*

**soc**

Start by using the facts such as the punishment vs. crime rates for different states this will give your reader a better understanding of how punishment helps to deter crime there is a wealth of knowledge on how states without capital punishment have at least 10% more crime ...
*May 23, 2010*

**chem can u check answer please**

The answer is D because if red litmus is immersed in acid it will not be affected red litmus turns blue only if put in *Base, futhermore Blue litmus immersed in acid will turn red.
*May 23, 2010*

**physics**

A steel cable is stretched across a gorge. The cable is 190 m long and has a mass of 44 kg. When one end of the cable is struck with a hammer, a wave pulse travels down the cable, reflects at the far end, and is detected back at the first end 14 s later. What is the speed of ...
*May 18, 2010*

**physics**

A steel cable is stretched across a gorge. The cable is 190 m long and has a mass of 44 kg. When one end of the cable is struck with a hammer, a wave pulse travels down the cable, reflects at the far end, and is detected back at the first end 14 s later. What is the speed of ...
*May 18, 2010*

**Contemp. World History**

I have to write a paper tonight answering the question: What is the greatest threat to US supremacy today? Its a opinion paper but I need some media sources to back up my argument. I am having a hard time brainstorming ideas and i feel stuck. Any suggestions?
*May 13, 2010*

**BIO. LIFE SCIENCE**

THE OFFSPRING OF A CROSS BETWEEN A PLANT WITH PURPLE FLOWERS AND A PLANT WITH WHITE FLOWERS ARE 23 PLANTS WITH PURPLE AND 26 WITH WHITE FLOWERS. USE THE LETTER P FOR PURPLE AND p FOR WHITE. WHAT R THE GENOTYPES OF THE PARENT PLANTS.
*May 12, 2010*

**BIO. LIFE SCIENCE**

IN GARDEN PEAS, THE ALLELE FOR TELLOW PEAS IS DOMINATE T OTHE ALLELE FOR GREEN PEAS. SUPPOSE YOU HAVE A PLANT THAT PRODEUCES YELLOW PEAS, BUT YOU DONT KNOW WHETHER IT IS HOMOZYGOUS DOMINANT OR HETEROZYGOUS. WHAT EXPERIMENT COULD YOU DO TO FIND OUT?
*May 12, 2010*

**physics**

A 20 kg slender rod pivoted at its center has a length of 6 m. A motor applied a torque of 2400 Nm on the rod to turn it from rest. a) Find the the average power by the motor when the rod rotates an angle of 500 radians. b) Find the instantaneous power of the motor at the ...
*April 28, 2010*

**Chemistry**

The answer is 9.037x10^-3 but I having trouble arriving to this answer.
*April 15, 2010*

**Chemistry**

When a sample of PCl5(g) (0.02087 mol/L) is placed in 83.00 L reaction vessel at 491.0 °C and allowed to come to equilibrium the mixture contains 103.0 grams of PCl3(g). What is the equilibrium concentration (mol/L) of Cl2(g)? PCl5(g) = PCl3(g)+Cl2(g) Molar Mass PCl5(g) ...
*April 15, 2010*

**English**

How Would you make a one paragraph thesis 3rd person on an architecture career
*April 14, 2010*

**physics**

A toy rocket is fired off a platform with an initial speed of 223 ft/sec at an angle of elevation of 32 degrees and achieves a maximum height of 291 ft. How how above the ground was the platform?
*April 6, 2010*

**physics**

Suppose a fixed cannon is to fire a projectile at an enemy tank, which is moving toward the cannon at a speed of 15 mph. If the cannon is to fire at the moment the tank is 3 miles from the cannon and the muzzle speed of the cannon is 1100 mph, what is the correct equation to ...
*April 6, 2010*

**vector geometry**

Suppose a fixed cannon is to fire a projectile at an enemy tank, which is moving toward the cannon at a speed of 15 mph. If the cannon is to fire at the moment the tank is 3 miles from the cannon and the muzzle speed of the cannon is 1100 mph, what is the correct equation to ...
*April 6, 2010*

**physics**

Suppose a fixed cannon is to fire a projectile at an enemy tank, which is moving toward the cannon at a speed of 15 mph. If the cannon is to fire at the moment the tank is 3 miles from the cannon and the muzzle speed of the cannon is 1100 mph, what is the correct equation to ...
*April 6, 2010*

**Physics**

A pilot flies an airplane in a vertical circular loop at a constant speed õ = 160 m/s. If the pilot’s apparent weight at the top of the loop is one-third of his true weight when he is on the ground, find the radius R of the plane’s circular path. answer is ...
*March 19, 2010*

**Calculus**

Verify that the volume of a cylinder of radius r and height h is given be the formula v= pi*r^2*h using cylindrical shell method.
*March 18, 2010*

**Chemistry**

Commercial bleach contains 5.25% (by mass) of NaClO in water. It has a density of 1.08 g/mL. Calculate the molarity of this solution. (Hints: assume you have 1 L of solution (mass 1080 g); molar mass of NaClO is 74.4 g/mol)
*March 3, 2010*

**chemistry**

Commercial bleach contains 5.25% (by mass) of NaClO in water. It has a density of 1.08 g/mL. Calculate the molarity of this solution.
*March 3, 2010*

**Math**

Explain how four red marbles can make up 1/3 of a group of marbles and three blue marbles make up 1/4 of the same group.
*February 23, 2010*

**Physics**

A basketball player attempting a free throw shoots the ball at an angle of 35 above the horizontal. The basket is 4.21 m from the foul line and 3.05 m above the floor. If the ball is released at a height of 1.83 m above the floor and it goes through the basket, what's the ...
*February 11, 2010*

**Physics**

A sprinter starts from rest and reaches his top speed in 4 seconds running with a constant acceleration. He then maintains that top speed and finishes the 100 m in the overall time of 10 seconds. What is his acceleration?
*February 9, 2010*

**Physics**

At t=0 car A and truck B are 350 m apart on a straight road. Starting from rest car A speeds up with a constant acceleration of 10 m/s^2. Truck B is travelling in the opposite direction with a constant speed of 15 m/s. How far away is car A from its starting point when the two...
*February 9, 2010*

**Physics**

A flowerpot falls off a windowsill and falls past the window below. It takes the pot 0.42 s to pass this window, which is 1.90 m high. How far is the top of the window below the windowsill from which the flower pot fell?
*February 8, 2010*

**Chemisty**

ok i got 0.882, is that correct? How do I calculate the mass of water in the container?
*February 6, 2010*

**Chemisty**

A student heats 10.8 g of lead to a temperature of 90.5 C. He places the hot lead into a container of water, initially at a temperature of 24.6 C; the final temperature of the water and lead is 25.2 C. What quantity of heat was lost by the lead?
*February 6, 2010*

**Chemistry**

A student places 100 mL of tap water in a beaker and uses both a thermometer and a temperature probe to measure temperature. The temperature of the water as measured by the thermometer is 27.7 C. The temperature of the water as measured by the temperature probe is 24.9 C. The ...
*February 1, 2010*

**physics**

Find the direction of the vector represented by the following pair of components: Ax= -3.15 m, Ay= 6.85 m. Find theta measured from the +x direction I don't know where to begin on this, could anyone guide me or give me steps?
*January 28, 2010*

**Trig**

Let O represent the origin and P be the point (9, -4). Find the positive angle (counterclock wise direction)that the line segment OP makes with the positive x-axis. the answer is 5.86 radians but i keep getting 0.418 radian. please help and show work
*January 24, 2010*

**Trig**

Let O represent the origin and P be the point (9, -4). Find the positive angle (counterclock wise direction)that the line segment OP makes with the positive x-axis. the answer is 5.86 radians but i keep getting 0.418 radian. please help and show work
*January 24, 2010*

**calculus (related rates)**

A particle moves in the plane along the curve y=xln(x). At what rate is the distance from the origin increasing at the moment its x-coordinate is 2 cm and its x-coordinate is increasing at a rate of 17 cm/sec?
*October 27, 2009*

**calculus**

T^(1/3)=e^(r/10)m^(3/2) If the mass and radius are given as m= 2 mg and r= 5mm, and the rates of change of the temperature and radius are given as 3 deg/sec and 1 mm/sec, what is the rate of change of mass (m)?
*October 27, 2009*

**chemistry**

why can I not use the formula m1v1=m2v2 for the following question: What volume of 1.20 M NaOH will be needed to neutralize 225 mL of 3.0 M sulfuric acid? I get 0.56 L but the answer should be 1.1 L. When am I able to use that formula and when can I not?
*October 18, 2009*

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