Concepts Of Physics MCQ Edition [Volume 1]PhysicsRest and Motion Kinematics
Choose the correct statements:
Options
- AOver a time interval, the average velocity of a particle travelling on a straight line is zero. It is possible
- BOver a time interval, the average velocity of a particle is zero. It is possible that its instantaneous veloci
- CThere can be a situation where | d v dt | 0 while d dt | v | = 0 .
- DIn a given time interval, the average speed of a particle is never smaller than the magnitude of its average v
Correct answer
D. In a given time interval, the average speed of a particle is never smaller than the magnitude of its average v
Step-by-step solution
For statement (1): Since the particle moves on a straight line and its average velocity is zero, its net displacement is zero. This implies the particle must have reversed its direction to return to the starting point. For a continuous velocity-time graph (as infinite acceleration is not permitted), the velocity must pass through zero. Thus, statement (1) is incorrect. For statement (2): If a particle moves in a closed 2D or 3D loop (such as a circle) and returns to its starting point, its net displacement is zero,