Fictitious Force

A fictitious force (also called a pseudo force) is an apparent force that acts on all masses in a non-inertial frame of reference, such as a rotating reference frame. So, a fictitious force is one that seems to exist because a frame of reference is accelerated. The forces may be treated algebraically like a real force, but the fictitious forces do not necessarily obey Newton’s first law.

One example is the centrifugal force, another one is the Coriolis force.

Wikipedia entry

Conservation of mechanical energy

Conservation of mechanical energy (potential energy + kinetic energy) discussed in a class given at MIT by Prof. Walter Lewin (course 8.01, Physics I: Classical Mechanics, fall 1999). Motion of car in a loop explained at 23:50, with a (deadly) amusing experiment at 45:40.

Topics covered in this lecture:

Work – Conservative forces – Potential energy – Kinetic energy – Mechanical energy

(Young and Freedman, chap. 6)