Wednesday

September 2, 2015
Number of results: 66,104

**Physics**

Is this correct?? Metal block weighs 500g in air and 446g completely submerged in water. Calculate density and relative density. Density of water = 1000kg/m3 BF (Buoyant force) will be 500g-446g = 0.54 g (or 0.054 kg). For volume: If BF = Density(water)*V*g then V = BF/density...
*April 10, 2015 by Danny*

**science(physics)**

Density is the ratio of mass to volume. Mercury has a density of 1.36 x 10^4 kg/m^3. What is the density of mercury in units of g/cm^3?
*September 5, 2007 by jen*

**Mechnical principles**

Mtal block weighs 500g in air and 446g completely submerged in water. Calculate density and relative density. I know relative density is density of material/density of water (1000kg/m-3)
*April 9, 2015 by Danny*

**Physics**

mass of an unknown sample is 0.240 kg in air and 0.208 kg when in oil of density=800 kg/m^3. Determine volume and density. Is the density 0.240/800?
*December 15, 2012 by Helen*

**physics**

mass of an unknown sample is 0.240 kg in air and 0.208 kg when in oil of density=800 kg/m^3. Determine volume and density. Is the density 0.240/800?
*December 18, 2012 by Helen*

**Physics-Math**

1.5 m3 of water is mixed with 0.50 m3 of alcohol. Density of water is 1000 kg m–3 and density of alcohol is 800 kg m–3. Whats the density of the mixture with volume 2.0 m3?
*September 13, 2011 by rohan*

**science (density)**

1) mass=100g, volume=10ml,density= 2) volume=7ml, mass=70g, density= 3) mass=50g, volume=10cm3, density= 4) volume=30cm3,mas=90g,density= 5) mass=120,volume=6ml,density= Thanks everyone i apresheate your help.
*October 9, 2008 by Carly*

**science (density)**

1) mass=100g, volume=10ml,density= 2) volume=7ml, mass=70g, density= 3) mass=50g, volume=10cm3, density= 4) volume=30cm3,mas=90g,density= 5) mass=120,volume=6ml,density= Thanks everyone i apresheate your help.
*October 9, 2008 by Carly*

**physics**

1.5 m3 of water is mixed with 0.50 m3 of alcohol. Density of water is 1000 kg m–3 and density of alcohol is 800 kg m–3. Whats the density of the mixture with volume 2.0 m3?
*September 13, 2011 by lola*

**physics**

The density of liquid carbon dioxide is about 0.8 g/cm^3. What volume fraction inside the fire extinguisher (when full) is occupied by CO2? The density of CO2 gas is negligible compared to the density of liquid CO2. My answer was 75%. Please verify. Thanks.
*December 23, 2013 by Alice*

**physics**

a) what is the density of a log floating in salt water if 42% of its volume is exposed? The density of salt water is 1025 kg/m^3 (b) What is the density of a sample of metal that sinks in water at 7.2 m/s^2
*November 22, 2009 by Sandhya*

**Physics**

What is the acceleration of an 0.4m aluminum cube with a density of 2.72 in a beaker of methanol, which has a density of .791?
*February 1, 2012 by Daisy*

**physics ( DENSITY )**

Assume that the density of a human is 1.13 g/cm3. What is the volume of a 51.5 kg person?
*May 31, 2012 by alyssa*

**physics**

A 650 kg weather balloon is designed to lift a 4600 kg package. What volume should the balloon have after being inflated with helium at 0 degrees celcius and 1 atm pressure to lift the total load? The buoyancy force must equal the weight lifted. Let V be the volume. g*[(He ...
*May 9, 2007 by Anonymous*

**Physics**

Estimate the density of the water 6.0 deep in the sea. By what fraction does it differ from the density at the surface?
*November 15, 2011 by Anonymous*

**physics**

Why we use square root of density in Grahms law instead of simpl density?
*September 25, 2013 by Anonymous*

**physics**

What is the apparent weight of a 36 kg block of aluminum (density 2700 kg/m3) completely submerged in a fluid with density 1300 kg/m3?
*November 30, 2010 by kate*

**physics**

a physics book has a height of 26cm, a width of 23cm, and a thickness of 3.9cm. what is the density of the physics book if it weighs 17N? the acceleration of gravity is 9.81m/s^2. answer in units of kg/m^3 i know density=mass/volume but it says to answer in units of kg/m^3... ...
*January 19, 2009 by Claudia*

**Physics**

i'm having trouble with this Which of the following statements about floating objects is correct? a. the object's density is greater than the density of the fluid on which it floats b. the object's density is equal to the density of the fluid on which it floats c. the ...
*February 20, 2009 by Bella*

**physics--pressure**

how high would the atmosphere extend if it were of uniform density throughout, equal to half the present density at sea level?
*March 22, 2009 by lisa*

**physics**

a ball of mass of 4kg,of density 4000kg/m3 is completely immersed in water of density 1000kg/m3.find the force of buoyancy.[g=10m/s2]
*October 23, 2012 by keerthiga*

**Ecology**

What are the types of population density measure and how each may be determined? Airkon Population density is a measurement of the number of people in an area. It is an average number. Population density is calculated by dividing the number of people by area. Population ...
*October 8, 2006 by airkon*

**Physics**

what is the general relationship between the density of solids and the density of liquids? Are you talking about the density of substance X in the solid state vs the density of the same substance in the liquid state. GENERALLY, solids have a higher density than the ...
*October 1, 2006 by Katrina*

**chemisrty**

can anybody give me the density of arsenic oxide at STP is this the correct formula volume = mass/ density thanks Yes, but if you want the density, it is density = mass/volume. The number I have seen floating around on this board is 17.8 g/L but the density of a gas and the ...
*February 4, 2007 by bex*

**Chemistry**

If the column of water in the water barometer fore to a height of 35ft, what would the atmospheric pressure be in mm Hg? mmH20X(density of water/density of Hg)= mmHg Density of water=0.99707 Density Hg=13.5340
*February 11, 2011 by Brian*

**chemistry**

given the density of helium is 0.1785g/cm3 and the density of argon is 1.784g/cm.3 estimate the density of neon
*October 28, 2012 by Jessa*

**physics**

A rectangular box of negligible mass measures 5m by 1m by .5m. How many kgs of mass can be loaded onto the box before it sinks in the water? V=5*1*.5 = 2.5m^3 density of water =1g/cm^3 =1000 kg/m^3 I also know that when the density of the mass is greater than the density of ...
*December 3, 2007 by Tammy*

**physics**

A rectangular box of negligible mass measures 5m by 1m by .5m. How many kgs of mass can be loaded onto the box before it sinks in the water? V=5*1*.5 = 2.5m^3 density of water =1g/cm^3 =1000 kg/m^3 I also know that when the density of the mass is greater than the density of ...
*December 3, 2007 by Tammy*

**Chemistry**

The mass of the earth is known to be about 5.98 X10^24kg assume that it is approx. spherical with an average diameter of 1.276X10^7 METERS. from these data calculate the average density of the earth(g/cm^3) could the earth be made mostly of water (density=1.00g/cm^3), abundant...
*August 30, 2011 by ALISON*

**Fluid ''Physics''**

A block of metal floats in oil of density 700Kg/m3 with 3/4 of volume in mass. Find the density of metal.
*November 6, 2011 by Said *

**physics**

AN EMPTY DENSITY BOTTLE WEIGHS 25GRAMS. IT WEIGHS 65GRAMS WHEN FILL WITH WATER. CALCULATE THE DENSITY OF THE LIQUID.
*July 7, 2013 by Anonymous*

**gr.11 physics help!**

When an iceberg floats in the ocean, what fraction of it is visible?( The relative density of ice is 0.92, and hte relative density of sea water is 1.03)
*January 6, 2010 by Andy*

**physics**

A slab of wood with mass m=1.7kg floats 78% submerged.the density of water is 1000kg/m.what is the density of the wood?
*March 25, 2015 by eunice*

**Physics**

The current density of an ideal p-n junction under illumination can be described by: J(V)=Jph−J0(e^qV/kT−1) where Jph is the photocurrent density, J0 the saturation current density, q the elementary charge, V the voltage, k the Boltzmann's constant, and T the ...
*October 3, 2014 by qwerty*

**Physics Fluids**

When a crown of mass 14.7 kg is submerged in water, an accurate scale reads only 13.4 kg. Is the crown made of real gold? Ok How do I do this problem I set up my free body diagram Net Force = ma = 0= Ft + Fb - Fg were Ft is the force of tension on the scale that was used to ...
*October 23, 2009 by Physics Fluids*

**physics**

What is the density of an unknown spherical substance with mass of 30 g and radius of 0.35 inches in kg/m3? (density= mass/ volume)
*October 9, 2010 by May*

**physics**

A person with a density of 980 kg/m3 floats in seawater of density 1025 kg/m3. What fraction of the person is submerged?
*November 26, 2012 by nic*

**Physics**

The density of a gas at s.t.p is 1.3kg/m3. Find the density of the gas at -15 degree celcius and at a pressure of 8cmHg.
*January 30, 2013 by Esther*

**PHYSICS**

A slab of wood with mass m = 1.7 kg floats 78% submerged.The density of water is 1000 kg/m3 . What is the density of the wood?
*April 3, 2015 by MONSOFT*

**physics**

Consider a long wire where the current density is not uniform but instead increases as you approach the center of the wire, so that at a distance r from the center the current density is J(r)= I/ 2PiRr. Find the magnetic field strength both inside and outside of this wire. I ...
*April 8, 2008 by Jessica*

**Density**

Can you identify a metal if you know its density? Explain It depends upon how accurately the density is determined. In some cases, especially where the "unknown" has a density that isn't close to another metal, yes, the density can identify the metal with a high degree of ...
*August 29, 2006 by John*

**Physics**

60 cm^3 of gasoline are mixed with 55 cm^3 of water. What is the average density of the mixture? the density of gasoline: 680
*November 11, 2009 by SB*

**Physics**

60 cm^3 of gasoline are mixed with 55 cm^3 of water. What is the average density of the mixture? the density of gasoline: 680
*November 12, 2009 by SB*

**Science**

What is the mass of 15mL sample of mercury? Look up the density of mercury. mass = volume x density. Make sure the density is in g/mL. If it isn't you will need to convert it. One place to find density of mercury is at www.webelements.com and click on element #80. I don't ...
*November 16, 2006 by Crystal*

**College Physics**

assuming that sea water has a density of 1.05 g/cm^3, what is the density of a submarine running submerged? wouldn't you need to know some other information; like the mass or volume of the submarine?
*November 21, 2011 by Amy*

**Physics**

A medical technician is trying to determine what percentage of a patient's artery is blocked by plaque. To do this, she measures the blood pressure just before the region of blockage and finds that it is 1.20×10^4 Pa, while in the region of blockage it is 1.15×10^4 Pa. ...
*November 12, 2008 by Andrea*

**AP Physics**

Assume that at sea-level the air pressure is 1.0 atm and the air density is 1.3 kg/m3. (a) What would be the height of the atmosphere if the air density were constant? 7.919 km (b) What would be the height of the atmosphere if the air density decreased linearly to zero with ...
*December 3, 2009 by Brian*

**Physics**

An infinitely long line of charge has linear charge density ë. Find the energy density of the electric field at a point a radial distance r from the wire. (Use the following as necessary: å0, ë, r.)
*August 31, 2013 by Lily*

**physics**

If you wanted to make a barometer that had a column of liquid about 6 feet tall, what would the density of the liquid have to be? 1 meter = 3.28 ft 1 inch = 2.54 cm Density Hg = 13.6 g/mL 1atm = 760 torr
*October 12, 2014 by jhon*

**physics**

A foam plastic of density of 0.58g/cm^3 is to be used as a life jacket.What volume of the plastic must be used if it is to keep 20percent by volume of an 80kg physics student above water in a lake if the average density of the student is 1.04g/cm^3
*January 4, 2012 by ceasar3*

**physics**

12. The ratio of the tensile (or compressive) strength to the density of a material is a measure of how strong the material is “pound for pound.” (a) Compare tendon (tensile strength 80.0 MPa, density 1100 kg/m3) with steel (tensile strength 0.50 GPa, density 7700 kg/m3): ...
*November 26, 2012 by mary*

**physics**

The weight of the atmosphere above 1 m^2 of Earth's surface is about 100,000 N. Density, of course, becomes less with altitude. But suppose the density of air were a constant 1.2 kg/m/s^3. Calculate where the top of the atmosphere would be.
*March 28, 2012 by Kristie*

**physics**

The weight of the atmosphere above 1 m^2 of Earth's surface is about 100,000 N. Density, of course, becomes less with altitude. But suppose the density of air were a constant 1.2 kg/m/s^3. Calculate where the top of the atmosphere would be.
*March 29, 2012 by Jim*

**physics**

The weight of the atmosphere above 1 m^2 of Earth's surface is about 100,000 N. Density, of course, becomes less with altitude. But suppose the density of air were a constant 1.2 kg/m/s^3. Calculate where the top of the atmosphere would be.
*March 31, 2012 by C*

**physics**

This is my problem: A particle with a density of 0.9g/ml is suspended in a solution that has a density of 1.1g/ml. It cannot be sedimented. Using the equation that describes the movement of a particle in a centrifugal field, describe why this is true. The issue I'm having is ...
*February 2, 2013 by Dave*

**Physics Archimedes buoyancy lab**

In calculating the density of a heavy solid. The string holding the heavy solid will cause error. specific gravity= (mass object in air)/ (mass object in air- mass object in water) = density When does it lead to an experimental density that is too high? Too low? not sure...
*December 12, 2007 by ~christina~*

**physics**

The nucleus of a hydrogen atom is a single proton, which has a radius of about 1.0 10-15 m. The single electron in a hydrogen atom normally orbits the nucleus at a distance of 5.3 10-11 m. What is the ratio of the density of the hydrogen nucleus to the density of the complete ...
*December 1, 2006 by MIke*

**Physics**

density of ice 917 kg/m^3, density of sea water is 1025 kg/m^3, a piece of ice floating has a volume of 5.2 m^3, what is the weight of the heaviest bear the ice can support without sinking?
*November 29, 2010 by Omar*

**Physics**

Update: Planets are not uniform inside. Normally, they are densest at the center and have decreasing density outward toward the surface. Model a spherically symmetric planet, with the same radius as the earth, as having a density that decreases linearly with distance from the ...
*April 30, 2015 by Katie*

**Physics**

A wooden cube of side 5cm floats in water 200cm^2 of its depth below the water surface and ats sides are vertical calculate the density of the wood in g/cm^3.(1) Density of water in 1g(m^-3).
*February 26, 2012 by Igbekele*

**physics**

Challenger Deep in the Marianas Trench of the Pacific Ocean is the deepest known spot in the Earth's oceans, at 10.922 km below sea level. Taking density of seawater at atmospheric pressure (p0 = 101.3 kPa) to be 1024 kg/m3 and its bulk modulus to be B(p) = B0 + 6.67(p −...
*April 16, 2011 by HELP!!!!*

**physics**

The density of liquid carbon dioxide is about 0.8 g/cm^3. What volume fraction inside the fire extinguisher (when it is full) is occupied by liquid CO2? The density of CO2 gas is negligible compared to the density of liquid CO2. Volume of fire extinguisher is 7.1*10^-3m^3; ...
*December 24, 2013 by Alice*

**physics (graphs)**

Hi, i'm doing a graph for density of an element as a function of atomic number. i'm trying to calculate the slope and it's asking me to include units. if density as a unit: g/cm^3, how would i write the units of the slope? which is basically density over atomic number. would ...
*September 26, 2012 by josh*

**phy**

Calculate the density for a rectangular block using the following measurements. Length: 2.70 cm, Width: 1.10 cm, Height: 9.09 cm, Mass: 72.17 g. Round your answer for density to 2 decimal places. Include the correct unit for density. Show your work
*May 18, 2011 by irtaza*

**Chemistry**

Please help!! If the density of fresh water at 4 degrees Celsius is 1.00g/mL, determine if the following objects will sink or float in water. 1.) A 200 feet (61m) tall pine tree that weighs 11,200 pounds (5,080 kg) and has a density of 0.88g/mL 2.) One gram of lead that has a ...
*February 12, 2015 by Tasha*

**College Physics**

A raft is made of wood with a density of 404 kg/m^3. It is 42 cm thick and its square area is 3.0x3.0 m^2. It is floating in seawater (density = 1025 kg/m^3). How many people of 68 kilogram can the raft hold before they start getting their feet wet?
*April 19, 2010 by L *

**PHYSICS**

Lead has a density of 1.13 104 kg/m3 at 0°C. (a) What is the density of lead at 86°C? ___kg/m3 (b) Based on your answer to part (a), now consider a situation in which you plan to invest in a gold bar. Would you be better off buying it on a warm day? Yes or No Explain.
*November 14, 2012 by Sarah*

**college physics**

find the weight of a piece of wood with a density of .5 g/cm cubed. which when attached to a 5kg stone in water it will sink. the density of the stone is 3g/cm cubed
*June 22, 2010 by josh*

**physics**

a mass of density bottle is 20g,when empty,70g when full of water and 55g when full of a second liquid.calculate the density of the liquid
*April 14, 2011 by frank*

**physics**

A density bottle has a mass of 35g when empty,85g when filled with water and 75g when filled with kerosene.Calculate the density of kerosene in g/cm3
*February 15, 2012 by Luc*

**physics**

A block of mass 200g and density 0.8g/cm3 is submerged in a liquid of density 0.2g/cm3. find minimum force required to keep the block floating.
*February 11, 2012 by Narayanan*

**Physics i.e science**

A density bottle has a mass of 35g when empty, 85g when filled with water and 75g when filled with kerosene. Calculate the density of kerosene in g/cm3.
*February 14, 2012 by Abbie*

**Physics**

A solid of density 5000 kg/m^3 weighs 0.5 kgf in air.It is completely immersed in water of density 1000 kg/m^3. Calculate the apparent weight of the solid in water.
*September 20, 2012 by Mayank*

**physics**

The galaxies in the universe are all flying away from each other. The speeds of nearby galaxies are proportional to the distance the galaxy is away from us. This relation, v=Hd is known as Hubble's law and the constant H is known as Hubble's constant. The evolution of our ...
*May 23, 2013 by hrdcvrdcv*

**Physics**

A plank of wood with a density of ρw = 650 kg/m3 and volume V = 0.65 m3 is floating in the ocean. (Assume the density of salt water is ρs = 1100 kg/m3) What is the volume of the block that is submerged? A) 0.23 m3 B) 0.38 m3 C) 0.42 m3 D) 0.51 m3 E) 0.56 m3
*July 23, 2013 by Trent Joseph*

**Physics**

The density of a solid is 130gcm^-3 at the temperature of 25 degree Centrigate.Find the Density at 150 degree Celcius if the linear expansion of the solid is 2.0*10^(-5)K^-1. I got the answer to be 129.03.
*April 14, 2015 by Sirneij*

**Physics**

The density of a solid is 130gcm^-3 at the temperature of 25 degree Centrigate.Find the Density at 150 degree Celcius if the linear expansion of the solid is 2.0*10^(-5)K^-1. I got the answer to be 129.03.
*April 14, 2015 by Sirneij*

**physics**

Density is calculated by dividing the mass of an object by its volume. The Sun has a mass of 1.99×1030 kg and a radius of 6.96×108 m. What is the average density of the Sun?
*December 5, 2010 by amber gorman*

**physics**

a block off wood (density = 0.5 g/cm^3) is floating in oil (density = 0.75 g/cm^3). The mass of the wood is 1500 g. Determine the volume of the oil displaced
*December 2, 2011 by steph*

**Chemistry/physics**

i have a density of 1.9x 10 (negative cubed)g/cm cubed.and i have a mass of 50.0 g. do i need to convert my density in order to find my volume?
*February 20, 2013 by Armoured sheperd*

**physics**

A wooden raft has 85% of its volume submerged when it is floating down a river with a density of water being 9.90x10^2 kg/m^3. What is the density of the wooden raft?
*November 11, 2014 by Anonymous*

**Physics**

An object floats in a liquid of density 1.2×10 kg/m3 with one quarter of its volume above the liquid surface. You are required to determine the density of the object
*March 10, 2015 by Kram *

**physics**

When a solid is dropped from the boat (floating in water)into the water ,then the level of water will fall if density of that solid body is greater than density of water i.e when that solid body sinks.WHY?I tried hard ,but i am unable to figured it out according to my ...
*October 1, 2014 by zoha*

**PHYSICS URGENT DUE IN 15 MINUTES**

The figure below (a) shows a sphere with a radius of r = 157 mm (density ñ = 1.24 g/cm³) suspended in water by a string. The ball is completely submerged in the water and the string is attached from the bottom of the water tank to the bottom of the sphere. What is the tension ...
*March 24, 2011 by Anonymous*

**Physics**

A balloon has a volume of 1000 m3 and a mass of 500 kg when empty. When full of helium, what is the maximum mass it can lift off the ground? The density of helium is 0.18 kg/m3 and the density of air is 1.29kg/m3.
*July 25, 2013 by Trent Joseph*

**physics**

a string supports a solid iron object of mass 180g totally immersed in liquid of density 800kg/m3. calculate the tension in the string if the density of iron is 8000kg/m3.
*June 15, 2014 by joelinho*

**physics-Please HELP!**

What percent error is introduced by weighing a Styrofoam block in air, which exerts an upward buoyancy force, rather than in vacuum? The density of air is 1.2 kg/m^3. (The density of Styrofoam is 160 kg/m^3)
*January 16, 2012 by Ashley*

**physics**

the weight of a solid is 80g in air and 50g in liquid of relative density 1.5. calculate the relative density of the solid.
*October 4, 2011 by pavatharani*

**physics ( math)**

Solve the Equations in terms of X: a. x/a = b/c b. s=xt^2/2 d. 4= 10/x e. 5= 5/x-5 f. 40=2((x10)2-5) g. x(y+2)/ (5y +8) 1.What is the average of 2/9 and 4/5? 2. Subtract 4.20 x 10^-5 from 6.468 x 10^-4 3.Given: D= density; M= Mass; V= Volume; and D= M/V a) If an object has a ...
*September 9, 2010 by K.C*

**physics**

mercury has a density of 1.36x10^4 kg/m. what is the density of mercury in units f g/cm?
*September 5, 2011 by amira*

**Urgent - Physics**

The U-shaped glass tube in the figure below contains two liquids in mechanical equilibrium: sea water of density 1.025 kg/L, and an unknown liquid of density ρ. The unknown liquid is in the left tube, floating on top of the water with a clearly visible interface. Use h1...
*January 27, 2009 by Jen*

**physics**

A person weights 685 N in air but only 497 N when standing in water up to the hips. Find (a) the volume of each of the person’s legs and (b) the mass of each leg, assuming they have a density that is 1.05 times the density of water.
*March 25, 2013 by Jess*

**Physics**

A block of mass 0.65 kg and density 650 kg/m³ is forced under the surface of the water by means of a spring (k = 60.0 N/m) that is fixed to the bottom of the container as shown in the figure. How much is the spring stretched? (the density of water is 1000 kg/m³).
*April 9, 2015 by Rutgers*

**Physics**

By how much does the H20 pressure exceed atmospheric pressure at 3 meters below the surface of a pool with fresh H20. I don't know what equation to use. You have to figure the weight of a column of water of some height h, and horizontal area A. Weight= mg= density*volume*g =...
*March 29, 2007 by Kristina*

**Physical Sciance**

Calculate the density for a rectangular block using the following measurements, Length: 2.70cm, Width:1.10cm, Height: 9.09cm, Mass: 72.17g. Round your answer for density to 2 decimal places. Include the correct unit for density.
*February 26, 2008 by Devin*

**physics**

a solid density D has weight W. If it is complerly immeresed ina liquid of density d then the apparent weight of the solid is ............
*December 29, 2011 by preeti*

**Dobson**

a)The element with the greatest density is osmium, which has a density of 22.6g/cm3. Calculate the mass of 32.1 cm3 of osmium. b)A team of students determined the density of a sample of wood to be 0.52 g/cm3. A handbook of chemistry reported the density of 0.548 g/cm3 for the ...
*March 26, 2010 by Anonymous*

**physics**

To determine the density of block of aluminum, you measured the mass at 101.1 g and a volume of 38.2 cm3 . When you looked up the value for aluminum density you found out it should be 2700 kg/m3 What is the percent error for your experimental data? a) 1.98% c) 19.8% b) 0.198...
*January 20, 2011 by Anonymous*

**Physics**

A helium balloon lifts a basket and cargo of total weight 2250 N under standard conditions, at which the density of air is 1.29 kg/m3 and the density of helium is 0.178 kg/m3 . What is the minimum volume of the balloon? The acceleration of gravity is 9.81 m/s2 . Answer in ...
*December 5, 2011 by help*

**Physics please help!!**

A satellite is in a circular orbit very close to the surface of a spherical planet. The period of the orbit is 2.23 hours. What is density of the planet? Assume that the planet has a uniform density.
*March 4, 2013 by Jose*