Physics is the science that studies motion and matter and how both work with forces and energy. It is a really big subject that has a lot of different “branches” of scientific study that include motion, sound, waves, electricity, light, sound, and even astronomy.
This science covers the tiniest particles and atoms all the way to the largest objects in the universe.When scientists talk about the “mass” of an object they are really referring to how much matter is in the object. It’s a total of all of the atoms, the density or how compact the atoms are, and the type of atoms in the object.
Scientists have decided that mass is usually measured in “kg” or kilograms, but figuring out the mass of an object is kind of complex. They use two common ways to get an objects mass:
The weight of an object is different from its mass. Weight is the measurement of the gravitation force on an object and it can change based on where it’s located. An object’s mass will never change.
An example of the weight change can be someone on Earth that weighs 100 lbs but would be weightless in outer space or weigh 38 lbs on Mars. The mass of that person would always be the same.
We sometimes calls “size” volume. This is because the type of molecules or atoms that make up an object also determine their “density” which helps to figure out its mass.
An example of this is a helium-filled balloon. It has a lot less mass than the same sized item that is made of solid steel. It shows that the size of an object doesn’t determine its weight.
One of the laws that seems odd but makes a lot of sense is the “law of conservation of mass.” This says that the mass of a closed system must remain constant over time, even when changes are made to the objects within the system.
An example of this would be to add sugar to water and then mix the contents. When you weigh the mixture the weight shows the weight of both the sugar and the water, even though it looks like the sugar dissolved in the water.
What is the measurement that scientists use for mass?
kg or kilograms
Are mass and weight the same?
no
What are the two methods used by scientists to figure out an objects mass?
inertial mass and gravitational mass
Which always remains the same: mass or weight?
mass
What is the definition of weight?
the measurement of the gravitation force on an object and it can change based on where it’s located
What is another word sometimes used for size?
volume