32 2Basics
Table 2.1The parity and time-reversal behavior of some vectors
Physical quantity r v p a F w L T E B
Parity − − − − − + + + − +
Time reversal + − − + ± − − ± + −
reversal behavior of the forceFand of the torqueTare positive, the dynamics is
reversible. Forces and torques, however, contain terms with the other time reversal
behavior, when friction plays a role. Then the dynamics is irreversible. The time
reversal behavior of tensors occurring in applications will be discussed later.