Question

A particle covers half of the circle of radius \( r \). Then the displacement and distance of the particle are respectively:

• A. \( 2\pi r, 0 \)
• B. \( 2r, \pi \)
• C. \( \frac{\pi r}{2}, 2r \)
• D. \( \pi r, r \)

Hint:

For circular motion, displacement is the shortest path between the initial and final points, while distance is the actual path travelled.

Answer 1

The Correct Option is D

When the particle moves along half the circumference of a circle, its displacement is the straight-line distance between the two points, which is \( \pi r \). The distance travelled is the half-circumference, which is \( r \).
Final Answer: \[ \boxed{\pi r, r} \]