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 measure it's apparent weight

- Ft = Fb - Fg
Ft = Fg - Fb
Ft = (mass of object)g - (density of fluid)g(volume of fluid)

density of object = (mass of object)/(volume of object)

mass of object = (density of object)(volume of object)

plug chug

Ft = (density of object) (volume of object)g - (density of fluid)g(volume of fluid)

ok were do I go from here I think that the volumes are suppose to be the same but I do not see how.

  1. 👍 0
  2. 👎 1
  3. 👁 1,325
  1. IF the thing is submerged, then


    The bouyant force is volumedisplaced*denstitywater.

    bouyantforce= 14.7/densitymaterial*density water.

    according to the measurements, the bouyant force is 14.7-13.3=1.4g

    then calculate the density of material:

    density material= 14.7/1.4 * 1g/cm^3
    which is about 10.5g/cm^3 So is this Gold?

  2. why are the volumes the same

    1. 👍 0
    2. 👎 0
  3. Fg on object = (it's density)(it's volume)g

    Fb = (density of water)(volume of water underneath object pushing it up)gravity

    your suppose to divide the two gravity is suppose to cancel out and the volume but the volumes are two different objects why are they the same

    1. 👍 0
    2. 👎 0
  4. What objects do you know when submerged change volume? Certainly chunks of metal do not.

Respond to this Question

First Name

Your Response

Similar Questions

  1. Physics Fluids

    When a block of volume 1.00 × 10–3 m3 is hung from a spring scale, the scale reads 10.0 N. When the same block is then placed in an unknown liquid, it floats with 2/3 of its volume submerged. The density of water is 1.00 × 103

    asked by Drew on April 6, 2015
  2. Physics

    The density of gold is 19 times that of water. If you take a gold crown weighing 32 N and submerge it in water, how much upward force must you exert on the submerged crown to keep it from accelerating?

    asked by Kelsey on October 8, 2013
  3. chemistry

    A 32.2 g iron rod, initially at 22.3 C, is submerged into an unknown mass of water at 63.9 C, in an insulated container. The final temperature of the mixture upon reaching thermal equilibrium is 58.6 C. What is the mass of the

    asked by HELP on March 19, 2012
  4. physics

    What is likely identity of a metal, if a sample has a mass of 67.5g when measured in air and an apparent mass of 59.5g when submerged in water?

    asked by fillemon on May 31, 2010
  5. physics

    A 5.0 kg block of some unknown material is suspended from a spring scale and submerged in water.? The spring scale reads 39.3 N. What is the specific gravity of the block? I get 5051.5 kg/m^3 but its incorrect.

    asked by Joseph on June 27, 2012
  1. physics

    When a container of water is placed on a laboratory scale, the scale reads 120 g. Now a 20-g piece of copper (of density 8.9 g/cm3) is suspended from a thread and lowered into the water, not touching the bottom of the container.

    asked by Anonymous on November 22, 2014
  2. physics

    the gravitational force exerted on a solid object is 5.00N.when the object is suspended from a spring scale and submerged completely in water the scale reads 3.50N. find the density of the object.

    asked by gosa on August 16, 2013
  3. physics

    You need to determine the density of a ceramic statue. If you suspend it from a spring scale, the scale reads 35.4 N. If you then lower the statue into a tub of water, so that it is completely submerged, the scale reads 12.4 N.

    asked by Kristen on April 11, 2012
  4. Physics

    Archimedes purportedly used his principle to verify that the king's crown was pure gold, by weighing the crown while it was submerged in water. Suppose the crown's actual weight was 14.0 N. The densities of gold, silver, and water

    asked by Victor on December 3, 2012
  5. physics

    a metal object is suspended from a spring balance scale. the scale reads 800 N when it is suspended in air and 700 N when the object is completely submerged in water. find the buoyant force, the volume and the density of the

    asked by ryan on February 3, 2015

You can view more similar questions or ask a new question.