Saturday

May 23, 2015

May 23, 2015

Total # Posts: 1,979

**Physics**

An ice puck of mass m revolves on an icy surface in a circle at speed v at the end of a horizontal string of length L. The tension in the string is T Find the mass of the puck when the length of the string is 2.2m , string tension is 5.0N , and the tangential speed of the puck...
*March 20, 2014*

**Physics**

An ice puck of mass m revolves on an icy surface in a circle at speed v at the end of a horizontal string of length L. The tension in the string is T Write the equation for centripetal force, and substitute the values T and L appropriately. Then with a bit of elementary ...
*March 20, 2014*

**Physics**

The diameter of the base of a tapered drinking cup is 6.6cm . The diameter of its mouth is 9.8cm . The path of the cup curves when you roll it on the top of a table. How much faster does the mouth move than the base? Express your answer using two significant figures.
*March 20, 2014*

**Physics**

Calculate the tension in a horizontal string that whirls a 1.9-kg toy in a circle of radius 2.3m when it moves at 2.8m/s on an icy surface. Express your answer to two significant figures and include the appropriate units. 1.9(2.8)^2 .. then divid by 2.3 I got 12.30 N , is this...
*March 20, 2014*

**Physics**

A Plane flies north at 215 km/h. A wind from the east blows at 69km/h. What is the plane's new velocity with respect to the ground in standard position
*March 19, 2014*

**Chemistry**

Suppose you tried to carry out a double replacement reaction by mixing equal voulumes of a solution that contains dissolved NAOH and a solution that contains dissolved NACL. WHat would you expect to happen when the two solutions were mixed? Expain?
*March 18, 2014*

**finance**

Linda Scales is now employed as the managing editor of a well-known business journal. Although she thoroughly enjoys her job and the people she works with, what she would really like to do is open a bookstore of her own. She would like to open her store in about eight years ...
*March 18, 2014*

**PHYSC101**

Hormones that regulate the development and functioning of reproductive organs are called ________ hormones.
*March 18, 2014*

**Physics**

The coefficient of static friction between the m = 3.20-kg crate and the 35.0° incline of the figure below is 0.260. What minimum force vector F must be applied to the crate perpendicular to the incline to prevent the crate from sliding down the incline?
*March 4, 2014*

**Math**

Need help with this problem: Isolate the variable: -4(2x - 7) = -36
*February 25, 2014*

**Math**

Need help with a few: Perform the indicated operation. Write your answer in simplest form: 4|5 / 20|3
*February 25, 2014*

**Math**

if i think i got this you would divide 697.50/55= which gives 12.68 an hour
*February 24, 2014*

**Biochemstry**

I got to that part where to find the moles of KH2PO4 but why base/ acid would equal the same. this is how i went about it then i got stuck 11.7 g of KH2PO4/136.08g/mol=.085 mol of KH2PO4 then to find M: 500 ml/1000ml=.5L .085/.5=17 M KH2PO4 then o lost myself
*February 24, 2014*

**Biochemstry**

1. A buffer was prepared by dissolving 11.7 g of KH2PO4 in 400 mL of water, and with the addition of concentrated solution of KOH the pH was adjusted to 7.10. The volume was then adjusted to 500 mL. What are the [PO43-], [HPO42-], [H2PO41-], and [H3PO4]? Use pKa values of 2.12...
*February 24, 2014*

**physics**

A block weighing 71.5 N rests on a plane inclined at 24.1° to the horizontal. The coefficient of the static and kinetic frictions are 0.26 and 0.13 respectively. What is the minimum magnitude of the force F, parallel to the plane, that will prevent the block from slipping...
*February 22, 2014*

**Physics**

What would be the answers to A and B?
*February 20, 2014*

**Physics **

A car is parked on a cliff overlooking the ocean on an incline that makes an angle of 21.0° below the horizontal. The negligent driver leaves the car in neutral, and the emergency brakes are defective. The car rolls from rest down the incline with a constant acceleration ...
*February 20, 2014*

**Science**

Which statement best describes the composition of magma?
*February 17, 2014*

**physics**

1 An object is thrown upward from the edge of a tall building with a velocity of 10 m/s. Where will the object be 3 s after it is thrown? Take g=10ms−2 15 m above the top of the building 30 m below the top of the building 15 m below the top of the building 30 m above ...
*February 17, 2014*

**Physics**

An electron with speed 2.35×107m/s is traveling parallel to a uniform electric field of magnitude 1.16×104N/C . How far will the electron travel before it stops? A=0.135m How much time will elapse before it returns to its starting point? I solved for the time it ...
*February 16, 2014*

**finance**

Mary Watson is 24 years old and single, lives in an apartment, and has no dependents. Last year she earned $45,000 as a sales assistant for Focused Business Analytics: $3,910 of her wages was withheld for federal income taxes. In addition, she had interest income of $142. ...
*February 6, 2014*

**Ghana National Lotto game**

I want to know the nexy ghana lotto drawn
*January 31, 2014*

**physics**

If the total positive charge is Q = 1.62×10−6C , what is the magnitude of the electric field caused by this charge at point P, a distance d = 1.53m from the charge? (Figure 1) Enter your answer numerically in newtons per coulomb.
*January 27, 2014*

**physics**

What is the magnitude of the electric field a distance 3.0mm from an electron? Express your answer to two significant figures and include the appropriate units
*January 27, 2014*

**physics**

Two small charged balls have a repulsive force of 0.20N when they are separated by a distance of 0.90m . The balls are moved closer together, until the repulsive force is 0.58N . How far apart are they now? Express your answer to two significant figures and include the ...
*January 27, 2014*

**physics**

Three charges are fixed in the x−y plane as follows: 1.5nC at the origin (0, 0); 2.6nC at (0.65m , 0); –1.8nC nC at (0, 1.50m ). Find the force acting on the charge at the origin. Express your answers using two significant figures. Enter the x and y components of ...
*January 27, 2014*

**physics**

Three charges are fixed in the x−y plane as follows: 1.7nC at the origin (0, 0); 2.3nC at (0.60m , 0); –2.0nC at (0, 1.20m ). Find the force acting on the negative charge. Express your answer using two significant figures. Enter the x and y components of the force ...
*January 27, 2014*

**Physics**

What is the net force exerted by these two charges on a third charge q 3 = 45.0nC placed between q 1 and q 2 at x 3 = -1.145m ? Your answer may be positive or negative, depending on the direction of the force. Express your answer numerically in newtons to three significant ...
*January 27, 2014*

**Physics**

Two Ping-Pong balls each have a mass of 2.6g and carry a net charge of 0.500ìC . One ball is held fixed. At what height should the second ball be placed directly above the fixed ball if it is to remain at rest there? Express your answer to two significant figures and ...
*January 24, 2014*

**Physics**

A free electron and a free proton are exactly 0.70cm apart. Find the magnitude of the acceleration of the proton. Express your answer with the appropriate units. Find the direction of the acceleration of the proton. Find the magnitude of the acceleration of the electron. ...
*January 24, 2014*

**Physics**

Two small spheres spaced 20.0 centimeters apart have equal charge. How many excess electrons must be present on each sphere if the magnitude of the force of repulsion between them is 4.57×10 −21 newtons?
*January 24, 2014*

**Physics**

How much charge is contained in 9kg of protons? Express your answer to two significant figures and include the appropriate units.
*January 24, 2014*

**Physics**

How much charge is contained in 9kg of electrons? Express your answer to two significant figures and include the appropriate units.
*January 24, 2014*

**Math**

Three out of 200 machine parts were found to be defective. About how many parts would be expected to be defective out of 2500 parts?
*January 24, 2014*

**Math**

Three out of 200 machine parts were found to be defective. About how many parts would be expected to be defective out of 2500 parts?
*January 24, 2014*

**math**

The large container has 13.5 liters of milk. Chen wants to fill as many 3/4 liter containers as possible with this milk. How many containers will he be able to fill?
*January 22, 2014*

**Spanish**

I posted this yesterday and didn't get help. Now it is buried on the 3rd page. I am posting again. I hope that is ok. Are these correct? Complete the following statements with the correct form of the verb in parentheses. Some will be conjugated, while others will be left ...
*January 16, 2014*

**Spanish 1**

Thank you
*January 15, 2014*

**Spanish 1**

Are these correct? Complete the following statements with the correct form of the verb in parentheses. Some will be conjugated, while others will be left in the infinitive. 1. Mi esposo __________ que viajar a Panamá en agosto. (tener) -tiene 2. Todos nosotros queremos ...
*January 15, 2014*

**math**

A triangle has vertices with coordinates (2, 0), (3, -1), and (-2, -5). If the triangle is dilated by a scale factor of 3 with the origin as the center of dilation, what are the coordinates of the vertices of the image.
*December 19, 2013*

**math**

A triangle has vertices with coordinates (2, 0), (3, -1), and (-2, -5). If the triangle is dilated by a scale factor of 3 with the origin as the center of dilation, what are the coordinates of the vertices of the image.
*December 19, 2013*

**physics**

A thick metal slab carries a current I A uniform magnetic field B points perpendicular to the slab (and into the page). If point P on the slab is at a higher potential than point Q , what can we say about the charge carriers that produce the current in the slab? Need some help...
*December 18, 2013*

**Physics and magnets**

A rectangular loop of wire of mass m and resistance R slides on a friction-free horizontal table. There is a region of uniform magnetic field perpendicular to the table. What type of graph best describes the speed v of the loop as a function of time?
*December 18, 2013*

**magnetism**

infinitely long wire carries a current I100A. Below the wire a rod of length L 10cm is forced to move at a constant speed v=5m/s long horizontal conducting rails. The rod and rails form a conducting loop. The rod has resistance of R 0.4ohms. The rails have neglibible ...
*December 17, 2013*

**manetism help!**

A charged particle with charge q is moving with speed v in a uniform magnetic field. A second identical charged particle is moving with speed 2v perpendiculuar to the same magnetic field. The time to complete one full circular revolution for the first particle T1. The time to...
*December 17, 2013*

**magnetic**

A charged particle with charge Q is moving with speed V in a uniform magnetic field. A second identical charged particle is moving with speed 2V perpendiculuar to the same magnetic field. The time to complete one full circular revolution for the first particle is t1 . The time...
*December 17, 2013*

**Quick science question**

In the newspaper one day, you read that the highest tides of the season are expected in the next month. What can you infer about the positions of the Sun, Earth, and the Moon? What phase of the Moon will probably be visible?
*December 16, 2013*

**Civics**

What happened as a result of the so-called Intolerable Acts?
*December 14, 2013*

**Algebra**

-847
*December 13, 2013*

**Math**

A marching band was in a parade. The band members marched in 8 rows. There were 6 band members in each row. Explain how the fact that 5X6=30 can help you find 8X6. I need help with this question
*December 10, 2013*

**math**

Which of the following statements is always true of similar polygons
*December 9, 2013*

**Physics magnetism**

The inductor in the circuit has a resistance of 100 ohms connected to a long solenoid with a loop density of 100 turns per centimeter and 59 H inductance connected to a 12 V battery. When the switch has been closed for a long time, what is the magnetic field magnitude inside ...
*December 7, 2013*

**physics**

The circuit shown below has a 100 Ohm resistor and 50 Volt-sec/amp (a unit of inductance called the Henry) inductor connected to a 12V battery. It is a freshman physics tradition that inductors are very poorly The switch is closed at t = 0 seconds. What is the magnitude of the...
*December 4, 2013*

**physics**

An obnoxious brat assigns his 0.0221-kilogram pet mouse Mickey the role of stunt mouse by stuffing him into a spring gun and shooting him up into the air at some angle. During the launch process the spring transfers 0.707 J of energy into the \'mouse Earth gravitational ...
*December 3, 2013*

**physics**

An obnoxious brat assigns his 0.0221-kilogram pet mouse Mickey the role of stunt mouse by stuffing him into a spring gun and shooting him up into the air at some angle. During the launch process the spring transfers 0.707 J of energy into the \'mouse Earth gravitational ...
*December 3, 2013*

**Science, Physics, math, calculus**

You would like to shoot an orange out of a tree with your bow and arrow. The orange is hanging 5.00 m above the ground. You fire the arrow at 35.0 m/s oriented 30.0° above the horizontal from a height of 1.30 m while standing 47.0 m away on your first try. You may neglect ...
*November 24, 2013*

**Science, Physics, math, calculus**

Pool players often pride themselves on their ability to impart a large speed on a pool ball. In the sport of billiards, event organizers often remove one of the rails on a pool table to allow players to measure the speed of their break shots (the opening shot of a game in ...
*November 24, 2013*

**Science, Physics, math, calculus**

A toy rocket is fired at v0 = 41.2 m/s at an angle of è = 73.8 degrees with respect to the horizontal on flat level ground. Assuming that air resistance is negligible, what is its maximum height (H) and how far (R) will the rocket have traveled in the horizontal ...
*November 24, 2013*

**current and magnetism**

A current loop with radius 20 cm and current 2 A is in a uniform magnetic field of 0.5 T. Considering all possible orientations of the loop relative to the field, what is the largest potential energy difference (in Joules) you can find between two orientations? I tried the ...
*November 24, 2013*

**into computers**

What overriding philosophy of the Windows 8 operating system makes it unique compared to earlier Microsoft operating systems?
*November 20, 2013*

**magnets**

A proton with a velocity of 2.0 x 10^7 m/s in the horizontal (+x) direction enters a region of uniform magnetic field that is 1 meter wide and points out of the page with a magnitude of 0.05 Tesla. At what angle below the x-axis, in degrees, does the proton's trajectory ...
*November 20, 2013*

**magnetism**

A current of 20 mA flows in a single circular loop with a radius of 2 meters. A uniform magnetic field of 1.2 T points parallel to the plane of the loop. What is the magnitude of the magnetic moment of the loop in A-m^2? What is the magnitude of the torque on the loop in N-m?
*November 20, 2013*

**magnetism**

A current of 20 mA flows in a single circular loop with a radius of 2 meters. A uniform magnetic field of 1.2 T points parallel to the plane of the loop. What is the magnitude of the magnetic moment of the loop in A-m^2? What is the magnitude of the torque on the loop in N-m?
*November 20, 2013*

**Physics**

3. A positive helium ion He+ is released from rest at the surface of a +1000 V flat electrode. It travels in the +x-direction (in vacuum) across a 1 mm gap, passes through a small hole in a +0 V electrode that is parallel to the first one, and enters a region of magnetic field...
*November 19, 2013*

**physics**

Two forces act on an object. The first force has a magnitude of 17.0 N and is oriented 68.0° counter-clockwise from the x axis, while the 2nd force has x- and y-components (-19.0 N, 16.5 N). Express the magnitude and direction of the net force.
*November 14, 2013*

**Physics**

Three people pull simultaneously on a stubborn donkey. Jack pulls eastward with a force of 93.3 N, Jill pulls with 73.1 N in the northeast direction, and Jane pulls to the southeast with 181 N. (Since the donkey is involved with such uncoordinated people, who can blame it for ...
*November 14, 2013*

**Physics**

A 14.9-kg object hangs in equilibrium at the end of a rope (taken as massless) while a wind pushes the object with a 67.7-N horizontal force. Find the tension in the rope and the rope\'s angle from the vertical. The acceleration due to gravity is 9.81 m/s2.
*November 14, 2013*

**Physics**

To better understand the concept of static equilibrium a laboratory procedure asks the student to make a calculation before performing the experiment. The apparatus consists of a round level table in the center of which is a massless ring held in place with a pin. There are ...
*November 14, 2013*

**physics urgent help !**

if a 3e charge is at the origin and a magnesium nucleus is 3 cm from the originin the x-axis direction.what is the magnitude of the net electrostatic force a Boron nucleus would experience at the point half way between magnesium nucleus and 3e charge on the y-axis in N
*November 11, 2013*

**physics**

if 3e charge is at the origin and magnesium nucleus is 3 cm from the origin in the x-direction. what is the magnitude of the net force a boron nucleus would experience half way between magnesium nucleus and 3 e charge
*November 11, 2013*

**physics**

The magnitude of each force is 283 N, the force on the right is applied at an angle 41 and the mass of the block is 27 kg. The coefficient of friction is 0.283. The acceleration of gravity is 9.8 m/s2 . 27 kg μ = 0.283 283 N 41 degrees 283 N What is the ...
*November 10, 2013*

**physics**

A block is at rest on the incline shown in the figure. The coefficients of static and kinetic friction are μs = 0.7 and μk = 0.59, respec- tively. The acceleration of gravity is 9.8 m/s2 What is the frictional force acting on the 29 kg mass? Answer in units of N (...
*November 10, 2013*

**PreCal**

go to wolfram alpha and plug it in
*November 10, 2013*

**physics**

A block accelerates at 3.3 m/s2 down a plane inclined at an angle 27.0. m μk 3.3 m/s2 27 Find μk between the block and the in- clined plane. The acceleration of gravity is 9.81 m/s2 .
*November 10, 2013*

**physics**

Masses 19 kg and 9 kg are connected by a light string that passes over a frictionless pulley as shown in the figure ( The figure shows the 19 kg block on the table connected by a string through a pulley which is connected to the 5 kg block hanging off the table). The ...
*November 10, 2013*

**physics**

Masses 19 kg and 9 kg are connected by a light string that passes over a frictionless pulley as shown in the figure ( The figure shows the 19 kg block on the table connected by a string through a pulley which is connected to the 5 kg block hanging off the table). The ...
*November 10, 2013*

**physics**

A capacitor has a circular plate of radiusr=12cm that are at a distance of .2cm part.this is hooked up to 12 V battery. if this caoacitor is submerged in water what happens to the capacitance?
*November 10, 2013*

**physics**

if 3e charge is at the origin and magnesium nucleus is 3cm fom thr origin in the x-axis. what is the magnitude of the net electrostatic force a Boron nucleus would experience at a point half way between magnesium nucleus and 3e.
*November 10, 2013*

**physics**

if 3e charge is at the origin and the magnesium nucleus is 3cm from the origin in the +x direction, at what position along the x- axis should an electron be placed so that the electron experiences no net force?
*November 9, 2013*

**math**

Mortgage lenders base the mortgage interest rate they offer you on your credit rating. This makes it financially critical to maintain a credit score of 700 or higher. How much more interest would you pay on a $195,000 home if you put 20% down and financed the remaining with a ...
*November 9, 2013*

**calculus**

a spherical balloon filled with gas has a leak that permits the gas to escape at a rate of 1.5 cubic meters per minute. how fast is the surface area of the balloon shrinking when the radius is 4 meters?
*November 7, 2013*

**physics**

A body of mass 25kg moving at 3m/s on a rough horizontal floor is brought to rest after sliding through a distance of 2.5m on the floor.calculate the coefficient of sliding friction(g=10m/s^2)
*October 26, 2013*

**economics**

Clearly explain the different market structure and how they determine the degree of competition among firms and how they maximise profits in the short run and long run Cite the source within the text and bibliography
*October 19, 2013*

**Gen Chm II**

Determine the pressure-based Keq for the reaction: 2SO2(g) + O2(g)<--->2SO3(g) given that 1.00×10−2 moles of SO2 and 2.00×10−2 moles of O2 were initially placed in a 2.00 L reaction chamber. The chamber contained 7.5×10−3 moles of SO3 ...
*October 7, 2013*

**Chem**

An 80.0-gram sample of a gas was heated from 25 °C to 225 °C. During this process, 346 J of work was done by the system and its internal energy increased by 6635 J. What is the specific heat of the gas?
*October 6, 2013*

**Chem**

An 80.0-gram sample of a gas was heated from 25 °C to 225 °C. During this process, 346 J of work was done by the system and its internal energy increased by 6635 J. What is the specific heat of the gas?
*October 6, 2013*

**Chemistry **

Can someone walk me through how to work this I have no clue where to start. I have converted grams to moles and Celsius to kelvin but I don't know where to go from there. Thank you! A piece of dry ice (solid CO2, d = 0.900 g/mL) weighing 21.0 g is placed in a 0.870 L ...
*October 4, 2013*

**Brief Calc**

Very nice, thanks Reiny
*September 25, 2013*

**Brief Calc**

i submitted the answer steve had first and it came out correct for the previous question
*September 25, 2013*

**Brief Calc**

thank you that one was correct, i just had one other i couldn't get, the problem is find dy/dx using implicit differentiation: 4x+3y=xy i found the derivative to be... y-4/3-x same question as the last one, y=? dy/dx=? Thanks again for your help
*September 25, 2013*

**Brief Calc**

e^x y =3 find dy/dx using implicit differentiation the answer is -y Compare your answer with the result obtained by first solving for y as a function of x and then taking the derivative. y=? dy/dx=? help me out with these last two please I don't know what they are asking
*September 25, 2013*

**Chemistry**

A sample of impure magnesium was analyzed by allowing it to react with excess HCl solution: Mg(s) + 2 HCl(aq) → MgCl2(aq) + H2(g) After 1.27 g of the impure metal was treated with 0.100 L of 0.768 M HCl, 0.0125 mol HCl remained. Assuming the impurities do not react, what...
*September 22, 2013*

**Science/ Chemistry**

When 0.422 g of phosphorus is burned, 0.967 g of a white oxide (a compound of phosphorus and oxygen) is obtained. a. Determine the empirical formula of the oxide. So for the empirical Formula I got P_2O_5 now it wants me to Write a balanced equation for the reaction of ...
*September 22, 2013*

**Chemistry**

What is the maximum mass of S8 that can be produced by combining 85.0 g of each reactant? 8SO2 + 16H2S yields 3S8 +16H2O
*September 21, 2013*

**Calculus**

Find the Indefinite Integral without u substitution of the following a)(8x-3)/(12x^6) b) 2sqrtx(5x-6) c) (4x+3)/xsqrtx d) (5x-6)^2 / sqrt x e) 16x^2 + x - 20 / 4x^2
*September 18, 2013*

**further Mathematics**

Let A=(cosA -sinA) (sinA cosA) show that A^2=(cos2A sin2A) (sin2A cos2A)
*September 17, 2013*

**further mathematics**

Let P=(cosA sinA) (sinA cosA) Q=(cosB sinA) (sinB cosA) show that PQ=(cosA(A-B) sin(A B)) (sinA(A B) cos(A-B))
*September 17, 2013*

**math**

In a regular hexagon, what is the ratio of the length of the shortest diagonal to the length of the longest diagonal? Express your answer as a common fraction in the simplest radical form.
*September 8, 2013*

**physics**

A boy sledding down a hill accelerates at 1.20 m/s2. If he started from rest, in what distance would he reach a speed of 7.00 m/s?
*September 4, 2013*

**physics**

A boy sledding down a hill accelerates at 1.20 m/s2. If he started from rest, in what distance would he reach a speed of 7.00 m/s?
*September 4, 2013*