Density is used to measure the matter in a unit volume of an object whereas weight refers to the gravitational force applied of any object. The components of Density are mass and volume whereas, on the other hand, the components of weight are mass and gravity.

Here’s what some of the 5th graders have to say about density: Araceli: Density definition: density is how tightly pack the particles are in a object. If an object sinks it is more dense than the liquid you put in. If it floats it is less dense.

Fun Facts

• The density of an object is determined by two things: the mass of the molecules in the object, and how tightly packed the atoms are together.
• A brick has high density because it is made from molecules that have a lot of mass.
• Styrofoam is low density.
• Density and buoyancy are interconnected.

1. Density is the only thing affecting whether something floats or sinks. If an object has a higher density than the fluid it is in (fluid can mean liquid or gas), it will sink. If it has a lower density, it will float.

It seems to defy the laws of physics, but a paper clip made of steel can indeed float on the water surface. The high surface tension helps the paper clip – with much higher density – float on the water. The cohesive forces between liquid molecules are responsible for the phenomenon known as surface tension.

Key Concepts

1. The density of an object determines whether it will float or sink in another substance.
2. An object will float if it is less dense than the liquid it is placed in.
3. An object will sink if it is more dense than the liquid it is placed in.

The positioning of molecules affects the density of an object. Objects with tightly packed molecules are more dense than those where the molecules are spread out. Density plays a part in why some things float and some sink. Objects that are more dense than water sink and those less dense float.

Density is a measure of how heavy something is compared to its size. If an object is more dense than water it will sink when placed in water, and if it is less dense than water it will float.

Ice is less dense than liquid water which is why your ice cubes float in your glass.

An object floats when the weight force on the object is balanced by the upward push of the water on the object. If the weight force down is larger than the upward push of the water on the object then the object will sink. If the reverse is true then the object will rise – rising is the opposite of sinking.

As long as the water your body displaces weighs more than you do, you float. A human submerged in water weighs less (and is less ‘dense’) than the water itself, because the lungs are full of air like a balloon, and like a balloon, the air in lungs lifts you to the surface naturally.

Those with more body fat and less muscle usually float more easily. On average females have a higher body fat % 21-24% than males 15%-20%. Consequently females generally float more easily than males.

Hicks explained not everyone can float — it depends on body density and their ability to displace enough water to float. People with smaller or muscular body types tend to have trouble. RelaxNSwim further explains fat is less dense than muscle and bones, so fat floats more easily.

If an object has a greater density than water, it sinks. If it is less dense than water, it floats. Which type of body material—muscle or fat—had greater density than water and which had a lower density? So, as it turns out, athletes with very little body fat might have to work harder to stay afloat in the water.

The air that is inside a ship is much less dense than water. That’s what keeps it floating! As a ship is set in water, it pushes down and displaces an amount of water equal to its weight.

With a lack of oxygen, a person becomes unconscious and water eventually fills the lungs. A person will experience a laryngospasm, where the vocal chords spasm and seal that pathway. This can be seen in many drowning instances, especially when someone is trying to hold his or her breath underwater.

Normal things, even humans, can levitate if they are placed in a strong magnetic field.

The higher the frequency of the sound, the smaller the diameter of the objects it’s possible to levitate. Objects that are the right size to levitate must also be of the right mass.

Sound Waves Levitate and Move Objects.

Acoustic levitation is a method for suspending matter in air against gravity using acoustic radiation pressure from high intensity sound waves. It works on the same principles as acoustic tweezers by harnessing acoustic radiation forces.

Magnetic levitation (maglev) or magnetic suspension is a method by which an object is suspended with no support other than magnetic fields. Magnetic force is used to counteract the effects of the gravitational acceleration and any other accelerations.