Question

Fig. 13.18 depicts four x-t plots for linear motion of a particle. Which of the plots represent periodic motion? What is the period of motion (in case of periodic motion) 

• A.
• B.
• C.
• D.

Answer 1

The Correct Option is B, D

The correct options are: (b) and (d) are periodic
It is not a periodic motion. This represents a unidirectional, linear uniform motion. There is no repetition of motion in this case.
In this case, the motion of the particle repeats itself after 2 s. Hence, it is a periodic motion, having a period of 2 s.
It is not a periodic motion. This is because the particle repeats the motion in one position only. For a periodic motion, the entire motion of the particle must be repeated in equal intervals of time.
In this case, the motion of the particle repeats itself after 2 s. 
Hence, it is a periodic motion, having a period of 2 s.