Help with density of objects?
H! asked:
I need to make a prediction about the density of the following objects: liquid water, wooden cube, chunk of modeling clay, piece of Styrofoam, pack of 5 pennies, and a piece of potato. So obviously pennies don’t float because they have high density. Most woods do. But i have no idea how to rank the other objects. Could you please help me?
This is my prediction *from highest to lowest*
I need to make a prediction about the density of the following objects: liquid water, wooden cube, chunk of modeling clay, piece of Styrofoam, pack of 5 pennies, and a piece of potato. So obviously pennies don’t float because they have high density. Most woods do. But i have no idea how to rank the other objects. Could you please help me?
This is my prediction *from highest to lowest*
1. The coins
2. Chunk of modeling clay
3. Piece of a potato
4. Piece of Styrofoam
5. Wooden cube
6. Liquid water
water has the density of .5 so anything above that wont float
the density equation is:
mass / volume = density
Example: a wooden cude’s mass is 4g (grams). the volume of a penny is 2cm^3. the density of the penny is 2 grams per cm^3, the density.
to get the mass of the wooden cude just weigh it in grams.
to get the volume of the penny use the equation L*W*H Length times Width times Height or you can use the water displacement method to get mililiters.
Water’s density is 1000 kg/m^3. If an object floats (i.e. wood block, styrofoam) then its density is less than water.
From highest (likely to float)
1. styrofoam
2. potato
3. wooden cube
4. moddeling cube
5. coins
6 water because it wouldn’t float because it would just make itself part of the water that it’s in.
1
Materials listed with Densities as follows:
Liquid water 1000 kg/m3
FLOAT
Styrofoam 28-45 kg/m3
Wood 500-800 kg/m3
SINK
Potato 1056 kg/m3
Modelling clay 1400-1600 kg/m3
Pennies ~7000 kg/m3
The potato will be borderline whether it floats. Whole potatoes sink, but a piece may float depending on the shape, and if the water is pure.
Gain extra marks but pointing out that the clay could be moulded into a boat shape, and would then float.
Ok, in order to predict the density of objects you can use water as the reference to know which one is denser. According to Archimedes, water will displace the volume of water that will have a mass equal to the mass of the object that is immersed into it. This is what makes objects float, if an object is less dense than the water, then this one will displace a smaller volume of water than it would if it was denser than water. So knowing this, rearranging the materials you give by saying which one will sink the most you can know what their relative densities are.
From bigger density to lower density:
pennies
modeling clay
potato
water
wood
styrofoam
hope this helps.