Concepts Of Physics MCQ Edition [Volume 1]PhysicsRest and Motion Kinematics
The position of a particle moving on the X-axis is shown as a function of time in the figure.
Options
- AThe velocity is continuously positive from t = 0 to t = 6 s .
- BThe average velocity over the entire period shown is negative.
- CThe maximum speed is reached at t = 6 s .
- DThe particle comes to rest exactly 6 times.
Correct answer
D. The particle comes to rest exactly 6 times.
Step-by-step solution
The velocity of the particle is given by the slope of the position-time ( x-t ) graph, v = dx dt . Analyzing Option (1): The slope of the graph alternates between positive and negative values between t = 0 and t = 6 s . It is not continuously positive. Hence, option (1) is incorrect. Analyzing Option (2): The average velocity is defined as the total displacement divided by the total time, v_ avg = x_f - x_i t . From the graph, the initial position at t = 0 is x_i 15 m , and the final position at the end of the show