Saturday

April 25, 2015

April 25, 2015

Total # Posts: 343

**math**

From an observation tower that overlooks a runway, the angles of depression of point A, on one side of the runway, and point B, on the opposite side of the runway are 6 degrees and 13 degrees, respectively. The points and the tower are in the same vertical plane and the ...
*August 21, 2011*

**Math**

From an observation tower that overlooks a runway, the angles of depression of point A, on one side of the runway, and point B, on the opposite side of the runway are, and , respectively. The points and the tower are in the same vertical plane and the distance from A to B is 1...
*August 21, 2011*

**math**

Yes but why is it 45 degrees? I'm dividing 8 into 16 = .5 then cos-1 .5 = 60. Nothing I do is giving me 45 degrees. Hope you get notified when a thread is updated, I'm inclined to repost this incase. Thanks again for your great answering.
*August 21, 2011*

**Mathematics**

thank you
*May 28, 2011*

**Mathematics**

Hi, Can someone check this for me .. please A tuning fork has a wavelength 0f 136 centimetres. Given that the speed of sound is 340 metres per second what is the frequency of the tuning fork ?? Frequency = speed / wavelength Then 340 / 1.36m (136cm) = 250 Hz Thank you try to ...
*May 28, 2011*

**math**

2/27(x-3)√((x^2-6x+23)/y)rearrange the equation to make y the subject
*May 25, 2011*

**algebra**

collect all like terms 3x^2-5x^2+12y-3y+8x =-2x^2+9y+8x
*May 25, 2011*

**Alegbra 1 **

the answer is distance over time. total distance is 1500 miles total time is 3.5 hours. 1500/3.5=428.57 mph.
*May 20, 2011*

**maths**

(a)(i)use the composite rule to differentiate the function f(x)=(x^2-6x+23)^(3/2). (ii)use the composite rule and your answer to part (a)(i) to show that the function g(x)=(x-2)/(x^2-6x+23)^(3/2) has derivative g'(x)=(5+9x-2x^2)/(x^2-6x+23)^(5/2). (iii)find any staionary ...
*May 20, 2011*

**physics**

An inflated basketball has a gauge pressure of 9.0 lb/in^2. What is the actual pressure inside the ball?
*May 12, 2011*

**physics**

A 70 kg person sits on a 3.6 kg chair. Each leg of the chair makes contact with the floor in a circle that is 1.5 cm in diameter. Find the pressure exerted on the floor by each leg of the chair, assuming the weight is evenly distributed.
*May 12, 2011*

**calculus**

An airplane at a height of 2000 meters is flying horizontally, directly toward an observer on the ground, with a speed of 300 meters per second. How fast is the angle of elevation of the plane changing when this angle is 45 degrees?
*April 11, 2011*

**Physics**

Pushing on the pump of a soap dispenser compresses a small spring. When the spring is compressed 0.55 cm, its potential energy is 0.0035 J. What is the force constant of the spring? What compression is required for the spring potential energy to equal 0.0094 ?
*March 22, 2011*

**physics**

You raise a bucket of water from the bottom of a deep well. If your power output is 128 W, and the mass of the bucket and the water in it is 6.00 kg, with what speed can you raise the bucket? Ignore the weight of the rope.
*March 15, 2011*

**physics**

Never mind, i figured it out.
*March 15, 2011*

**physics**

A new record for running the stairs of the Empire State Building was set on February 3, 2003. The 86 flights, with a total of 1576 steps, was run in 9 minutes and 33 seconds. If the height gain of each step was 0.20 m, and the mass of the runner was 68 kg, what was his average...
*March 15, 2011*

**physics**

A 1.1 kg block is held against a spring of force constant 2.0×10^4 N/m, compressing it a distance of 0.20 m. How fast is the block moving after it is released and the spring pushes it away? v=____m/s
*March 15, 2011*

**pyhsics**

never mind, i figured out how to do this problem 1. K = 11J 2. v = 9.1m/s 3. W = 14J the wording was just alittle bit confusing
*March 15, 2011*

**pyhsics**

At t= 1.0s, a 0.61 kg object is falling with a speed of 6.0 m/s. At t= 2.0s, it has a kinetic energy of 25 J. 1. What is the kinetic energy of the object at t= 1.0s? 2. What is the speed of the object at t= 2.0s? 3. How much work was done on the object between t= 1.0s and t= 2...
*March 15, 2011*

**Physics**

A small plane tows a glider at constant speed and altitude. If the plane does 2.00X10^5 J of work to tow the glider 165 m and the tension in the tow rope is 2660 N, what is the angle between the tow rope and the horizontal?
*March 15, 2011*

**physics**

A 55-kg packing crate is pulled with constant speed across a rough floor with a rope that is at an angle of 44.7 degrees above the horizontal. If the tension in the rope is 155 N, how much work is done on the crate to move it 9.0 m? *looking for W=__J
*March 15, 2011*

**Physics**

Early one October, you go to a pumpkin patch to select your Halloween pumpkin. You lift the 2.8 kg pumpkin to a height of 1.4 m, then carry it 50.0 m (on level ground) to the check-out stand. Calculate the work you do on the pumpkin as you lift it from the ground? and How much...
*March 15, 2011*

**Physics**

531684.027J
*February 23, 2011*

**AP PHYSICS**

In a Young's double-slit experiment, the angle that locates the second-order bright fringe is 3.0°. The slit separation is 4.8 10-5 m. What is the wavelength of the light?
*February 16, 2011*

**Physics**

At t=0, a wave disturbance has the waveform that is shown in a figure. The wave has a velocity of 500.0 m/s to the left. What's the values for k and ω if the wave equation is to be written in the form: y(x,t)=A cos(kx±ωt+φo). What is the value for k, ...
*February 13, 2011*

**Physics**

Thanks.
*February 11, 2011*

**Physics**

Two waves are combined to form this standing wave equation of y(x,t) = (3 mm)sin[x/(2 m]cos[(100 rad/s)t] a. What's the amplitude of the right moving wave and left moving wave? b. What's the wavelength of the right moving wave and left moving wave? c. What's the ...
*February 11, 2011*

**AP Physics**

At a height of 5 meters above the surface of a freshwater lake, a sound pulse is generated. The echo from the bottom of the lake returns to the point of origin 0.140 s later. The air and water temperatures are 20°C. How deep is the lake?
*February 9, 2011*

**Science Physics**

A rubber ball of mass m1= 10kg is moving to the right with speed v1= 10m/s. it collides elastically with another ball of mass m2= 50kg, which is sitting at rest. m2 is larger than m1, what are the speeds of the balls, v1 and v2 after the collision?
*February 3, 2011*

**writing paper for political science**

Ok then I will start at that point.
*December 6, 2010*

**writing paper for political science**

Since it only wants recent history I gather then I don't need to go back to far ago. So I should just stick to the most recent events? Or should I start with the korean war? Would it be wise to mention the Korean war briefly if it is important to the current events?
*December 6, 2010*

**writing paper for political science**

Thanks of the responses. I came up with the country in order to do on the conflict with North Korea. Yeah I could use a tip on researching what about the conflict I should focus on. I got a bit overwhelmed. and I also was lost on how to cite sources into a paper with footnotes...
*December 6, 2010*

**writing paper for political science**

Confused on what do to do for this paper I have to write for a class here in a community college. I am to choose a country in asia, africa or Latin America like say South Korea. I am to research recent history and contemporary situation. Identify and explain using factual ...
*December 6, 2010*

**business**

18. Which of the following is not a ramification of too much or too little status in an organization? a. it inhibits communication b. solidarity is not developed c. it interferes with work d. it causes resentment and conflict e. it causes communication underload
*November 28, 2010*

**5th grade**

What is the answer
*November 19, 2010*

**5th grade**

Reggie and jay go for a walk every morning. Reggie walks 2 1/4 jay walks 1 3/8 miles less than reggie what is the total distance they walk every morning
*November 19, 2010*

**Chemical Engineering**

I got the same answer
*November 7, 2010*

**Physics**

can you tell me the magnitude of the force P and the mass of block C? show work please
*October 25, 2010*

**math**

distance over time. 18/2=9 so is traverling at 9 feet per second multiply by the amount need to turn one second into an hour and u will have your answer.60 x 60 just a clue to help.
*October 21, 2010*

**Astrology / Physics**

The calculations/concepts here are actually physics.
*September 20, 2010*

**Astrology / Physics**

How do we calculate the radial velocity after the recession velocity is known?
*September 20, 2010*

**Chemistry**

Does methanol absorb UV light?
*September 12, 2010*

**Chemistry**

Does water and methanol absorb light in the UV-Vis region?
*September 11, 2010*

**algebra**

Find the function value. f(x)=x^3 f(-8)=
*September 5, 2010*

**algebra**

Given the function k described by k(x)=8x, find each of the following. k(-13)= k(6)= k(24)=
*September 5, 2010*

**Chemistry**

In the reaction: Protection of 1-Phenylethanol by 3,4-Dihydro-2H-pyran, 1-phenylethanol, 3,4-Dihydro-2H-pyran and anhydrous ether were added first and stirred in ice-water bath before acid catalyst p-toluenesulfonic acid monohydrate was added. The reaction was kept at 0 deg ...
*September 4, 2010*

**Statistics**

One of the tests for Outlier is anything greater or smaller than 1.5 IQR. Why is 1.5 chosen to be the benchmark, instead of 2 or 1 IQR?
*August 31, 2010*

**Chemistry**

An NMR spectrum of fumaric acid in acetone was run. The following results were obtained: 1 sharp peak with 5 splittings at around 2 ppm (belonging to acetone) 1 broad peak at 3.789 ppm (integration 0.63) 1 sharp peak at 6.779 ppm (integration 1.00) (belonging to CH of fumaric...
*August 30, 2010*

**Chemistry**

An NMR spectrum of fumaric acid in acetone was run. The following results were obtained: 1 sharp peak with 5 splittings at around 2 ppm (belonging to acetone) 1 broad peak at 3.789 ppm (integration 0.63) 1 sharp peak at 6.779 ppm (integration 1.00) (belonging to CH of fumaric ...
*August 28, 2010*

**Chemistry**

In general, what are the conditions required for Schiff's Base to polymerise?
*August 21, 2010*

**Chemistry**

Sorry. What I meant was: How do we improve the efficiency of Flash Column Chromatography?
*August 19, 2010*

**Chemsitry**

How do we improve the efficiency of Column Chromatography?
*August 19, 2010*

**Pyschology**

the determining factors of gender identification and gender roles o State the factors that determine gender identity. o Explain how a person’s masculine and feminine traits can be described using the continuum of masculinity-femininity
*May 31, 2010*

**Biochemistry**

Is ATP an allosteric inhibitor for protease?
*April 2, 2010*

**Biology / Biochemistry**

How will the conformation of an Enzyme (a protease) be affected when the amino acid residue is substituted with glutamate instead of glutamine?
*March 28, 2010*

**Chemistry**

Beside the usual method of titrating with KMNO4, what is/are the alternative method/s to test for the presence/amount of oxalate in a compound?
*March 23, 2010*

**math**

-8<3x-5<-4 -8<3x-5 and 3x-5<-4 3x-5>-8 3x<1 3x>-3 x<1/3 x>-1 therefore 1/3>x>-1
*March 23, 2010*

**Chemistry**

Is Al(OH)3 soluble in KOH or K2C2O4•3H2O?
*March 23, 2010*

**Math 30**

Yes, 2^9.
*March 22, 2010*

**Chemistry**

Why is heating required for this formation: 6NaOH (aq) + Al2(SO4)3 (aq) ¨ 2Al(OH)3 (s) + 3Na2SO4 (aq)? Wouldn't freezing favour the formation of Al(OH)3 since freezing lower the KSP and more Al(OH)3 would precipitate?
*March 22, 2010*

**Chemistry**

This is the equation for the formation of Al(OH)3: 6NaOH (aq) + Al2(SO4)3 (aq) ¨ 2Al(OH)3 (s) + 3Na2SO4 (aq) Would any side products be formed if NaOH was added quickly into Al2(SO4)3?
*March 22, 2010*

**Chemistry**

During the preparation of K3[Al(C2O4)3].3H2O, NaOH was added slowly and with stirring over an approximately 10-minute period to a solution of Al2(SO4)3 solution. The combined solution was heated to almost boiling and left to stand for a few minutes. 1. Why does NaOH added ...
*March 22, 2010*

**math**

I calculated the average number of crashes over a 240 week period to be .0875... what formula do I use to calculate the probability that at least 19 crashes would occur over that 240 week period?
*March 16, 2010*

**Physics**

A room has a volume of 120 m^3. An air-conditioning system is used to replace the air in the room every twenty minutes, using ducts that have a square cross ection. Assuming that air can be treated as an incompressible fluid, calculate the length of a side of the square if the...
*March 16, 2010*

**Chemistry**

Cu(NH3)2^+ is a colourless compound. Will there be any absorbance at 600nm?
*March 16, 2010*

**math**

h(x) = 1.95 x + 72.85 h(x) = 1.95(35) + 72.85 h(x) = 141.10
*March 16, 2010*

**apchem**

For a typical commercial vinegar with a 5% acetic acid content, the density is about 1.01 grams per milliliter.
*March 16, 2010*

**apche,m**

For a typical commercial vinegar with a 5% acetic acid content, the density is about 1.01 grams per milliliter.
*March 16, 2010*

**spelling**

The plural of family is families. So the first sentence is right.
*March 16, 2010*

**Chemistry**

What is the colour of: 1. Cu+ 2. Cu2+ 3. Cu3+?
*March 16, 2010*

**Chemistry**

Aspirin equilibrium is : HC9H7O4(aq) + H2O (double arrow)C9H7O4^-(aq) + H3O^+ You have 2 tablets each containing 0.325g of active ingredient that you dissolve in water up to 225ml. Calculate the pH.
*March 14, 2010*

**Math**

x + 2y =1 --- (1) 8x + 8y =4 --- (2) From (1), x + 2y = 1 x = 1 - 2y --- (3) Sub (3) into (2), 8 (1-2y) + 8y = 4 8 - 16y + 8y = 4 -8y = 4 - 8 -8y = -4 y = -0.5 sub y = -0.5 into (3), x = 1 - 2(-0.5) x = 1 + 1 x = 2 CHECK: sub x = 2 and y = -0.5 into (1), 2 + 2(-0.5) = 1
*March 14, 2010*

**math**

-6x + 3 =-7 - 5x -6x + 5x = -7 - 3 -x = -10 x = 10
*March 13, 2010*

**Physics**

energy of 1 photon = (Plank constant x speed of light, c) / wavelength = 6.626 x 10^-34 x 2.998 x 10^8 / 2 x 10^-1 = 9.93 x 10^-25 J energy of 10^12 photons = 9.93 x 10^-25 x 10^12 = 9.93 x 10^-13 J
*March 13, 2010*

**Chemistry**

What is the stoichiometric ratio for Cu2+ ions with cuprizone to form the copper-cuprizone complex?
*March 13, 2010*

**math**

average of: 8; 10; 12; 14; 16 = (8 + 10 + 12 + 14 + 16) / 5 = 60 / 5 = 12
*March 13, 2010*

**math**

x+8y=33 ---- (1) -x+4y=3 ---- (2) (1) + (2), x + 8y + (-x + 4y) = 33 + 3 12y = 36 y = 3 sub y = 3 into (2), -x + 4(3) = 3 -x = 3 - 12 -x = -9 x = 9 CHECK: sub x = 9 and y = 3 into (1), 9 + 8(3) = 33
*March 13, 2010*

**math**

6m+n=47 --- (1) m-4n=12 --- (2) From (2), m = 12 + 4n --- (3) sub (3) into (1), 6(12 + 4n) + n = 47 72 + 24n + n = 47 25n = -25 n = -1 sub n = -1 into (3), m = 12 + 4(-1) m = 8 CHECK: sub m = 8 and n = -1 into (2), 8 - 4(-1) = 12
*March 13, 2010*

**Chemistry**

Copper(I) Iodide is synthesised by the equation: 2CuSO4.5H2O + 2KI + 2Na2S2O3.5H2O --> 2CuI + K2SO4 + Na2SO4 + Na2S4O6 + 10H2O Would it make a difference if anhydrous CuSO4 and Na2S2O3 are used instead? Why hydrous CuSO4 and Na2S2O3 are used instead?
*March 13, 2010*

**Chemistry**

What is the stoichiometric ratio for Cu2+ ions with cuprizone to form the copper-cuprizone complex?
*March 13, 2010*

**Chemistry**

How should I write the balanced chemical equation to represent the oxidation of Cu+ ion by air? [Cu(NH3)3]^+1 + 2H2O + ??? --> [Cu(NH3)3(H2O)2]^+2
*March 13, 2010*

**Chemistry**

Can [Cu(NH3)2]^+ and/or [Cu(NH3)3]^+ be oxidised by air to become [Cu(NH3)2]^2+ and [Cu(NH3)3]^2+ respectively?
*March 13, 2010*

**Chemistry**

What would be the most likely product(s) when you react CuI with NH4OH?
*March 13, 2010*

**Chemistry**

What is the chemical equation for: CuI + NH4OH ---> ??? This equation should oxidise Cu+ to Cu2+.
*March 13, 2010*

**Physics Tough question!**

o wow, i didnt even think of the geometrical way, thanks.
*March 8, 2010*

**Physics Tough question!**

A pond has the shape of an ice cream cone with the tip slices off and has a depth of 5.00m. The atmospheric pressure above the pond is 1.01 *10^5 Pa. The circular top surface (radius = R2) and circular bottum (radis = R1) of the pond are both parrallel to the ground. The angle...
*March 8, 2010*

**Physics**

Also, teacher gave me a hint that "r(radius)" was suppose to cancel during the formula manipulation process..
*March 3, 2010*

**Physics**

A hypothetical spherical planet consists entirely of iron (p=7860 kg/m^3). Calclate the period of a satellite that orbits just above its surface. I started out with the density formula P=M/V, but i kept subbing in other formulas, but i get stuck..can someone help me? thanks. I...
*March 3, 2010*

**Physics, help please!**

Im sorry! I meant density! It was represented by a small p, so i thought pressure >_< Anyways, density = mass/volumne. My teacher gave me a hint about radius cancelling each other off in the formula manipulation. Hope this helps!
*March 2, 2010*

**Physics, help please!**

A hypothetical spherical planet consists entirely of iron (p=7860 kg/m^3). Calclate the period of a satellite that orbits just above its surface. I started out with the pressure formula P=M/V, but i kept subbing in other formulas, but i get stuck..can someone help me? thanks.
*March 2, 2010*

**Physics**

A hypothetical spherical planet consists entirely of iron (p=7860 kg/m^3). Calclate the period of a satellite that orbits just above its surface. I started out with the pressure formula P=M/V, but i kept subbing in other formulas, but i get stuck..can someone help me? thanks.
*March 2, 2010*

**Physics**

Thanks
*February 16, 2010*

**Physics**

A 3.00 uF and a 5.00 uF capacitor are connected in series cross a 30.0V battery. A 7.00 uF capacitor is then connected in parallel across the 3.00 uF capacitor. a)Calculate the equivalent capacitance of the circuit I think the answer is 3.33 uF. b)Determine the voltage across ...
*February 16, 2010*

**Chemistry**

What are the possible side reactions for this case?
*February 12, 2010*

**Chemistry**

I recently did an experiment on Aldol Condensation, by reacting Benzaldehyde with Acetone to form Dibenzalacetone. The proposed stoichiometric ratio of Benzaldehyde:Acetone is 2:1. What would be the implications if either of the reactants is in excess?
*February 12, 2010*

**Phyics**

Thanks a lot!
*February 10, 2010*

**Phyics**

A resistor has a resistance R, and a battery has an internal resistance r. When the resistor is connected across the battery, ten percent less power is dissipated in R than would be dissipated if the battery had no internal resistance. Show that the ratio r/R is equal to 0.054...
*February 10, 2010*

**Geometry**

What is the sum of the measures of the interior angles of a convex octagon? What is the sum of the measures of the interior angles of a convex decagon? What is the measure of one interior angle of a regular polygon with 20 sides? Thank You! (:
*February 3, 2010*

**math**

Isolate x or y in either equation and then subsitute it in to the other equation. x+y=56 x=56-y Subsitute into the other equation: Since x=56-y, the other equation becomes (56-y)+3y=56 56+2y=56 subtract 56 from both sides 2y=0 y=0/2 y=0 then x must be 56
*January 21, 2010*

**physics**

It decreases very very slightly. Mabye from 9.81m/s^2 to 9.80m/s^2, MABYE. Depending on how far you travel away from Earth, the force due to gravity is decreases exponentially. This can be proven with Fg=Gm1m2/r^2 where G=Gravitational constant(6.67*10^-11 N*m^2/kg^2)
*January 21, 2010*