Bridge is a very important human invention. It is essential
to our daily life and it facilitates a convenient transport.
Building is a very important human invention that is indispensable
to our daily life. The main functions of a building are
to protect us from wind and rain and provide us a safe and
comfortable environment for working and rest.
In physics, we encountered many numbers
that we believe do not change with time. These numbers
are usually called constants or more appropriate, universal
constants.
Mechanics is the first topic to be
studied in most, if not all, high-school physics courses.
Also, many students think that it is the easiest to understand.
The train moves thousands of passengers
at a hundred km per hour, making frequent stops along
the way. What kind of acceleration is involved? How powerful
is the engine? By using simple Newtonian mechanics, we
can answer these questions quantitatively.
