1) The ratio of the actual damping coefficient to the critical damping coefficient is called damping factor.

2) When a body moves with simple harmonic motion, the product of its periodic time and frequency is equal to

3) In a vibrating system, if the actual damping coefficient is 40 N/m/s and critical damping coefficient is 420 N/m/s, then logarithmic decrement is equal to

4) For high speed engines, the cam follower should move with

5) In a coupling rod of a locomotive, each of the four pairs is a __________ pair.