Skip to main content

Physics of Media Arts: Conceptual Physics for Students of the Media Arts

Aaron Wong

Section 3.4 Derived Units

“-----”
―-----
We can think of the SI units as the building blocks for more complicated concepts. For example, speed is the measure of how far an object travels in a particular amount of time. This means that we can’t have speed unless we have both distance and time. The purpose of the SI base units is that it gives us the foundation upon which we can build all of the other physics concepts. Everything from here forward will involve some combination of those units.
Here are some examples of some physics concepts and their associated units:
  • Speed (\(\frac{\text{m}}{\text{s}}\)): A measure of how far an object travels in a particular amount of time.
  • Acceleration (\(\frac{\text{m}}{\text{s}^2}\)): A measure of the change of speed over a period of time.
  • Force (\(\frac{\text{kg} \cdot \text{m}}{\text{s}^2} = \text{N}\)): A measure of the push or pull applied to an object. Since this unit is used so frequently in combination with other units, it is given its own symbol \(\text{N}\) (Newtons). Mathematically speaking, this unit is just a substitution that allows us to write certain combinations of units in a less complicated manner.
Some of the units are given names to simplify the concepts. For example, the unit of force is a Newton, and it can be understood as the amount of force needed to accelerate a one kilogram mass at the the rate of one meter per second squared. There are also some concepts that have units that are easily calculated, but are extremely challenging to describe directly. For example, momentum is calculated as the product of mass and velocity, but what it measures might be described as the amount of stored motion within a mass.
It would be good to review Section 2.4 for multiple unit conversions and unit conversions involving exponents.

Activity 3.2. Unit Calculation Practice.

Intro Text

Instructions.

Instructions
PrevTopNext