Question

A particle is moving on a straight line, during the time t=0 to time t = T, total distance travelled by it is D and during the same period the magnitude of its displacement is r. Then which of the following is true?
(A) D must be equal to r (B) D may be equal to r
(C) D may be less than r (D) D must be less than r

Answer 1

Option A is the correct answer. because the time period of the particle is same. It displacement is r when it start at time t = 0 and stop while time t t = T.

Answer 2

D must be equal to r.

• The total distance traveled by the particle during the time t=0 to t=T is D while the magnitude of displacement is r.
• The distance refers to how much ground the particle has covered in the given time.
• Displacement is defined as the change in position of the object.
• Hence we can see that distance depends on the path of travel while displacement only depends on initial and final positions.
• In the given question, the particle is moving along a straight line.
• Hence, the distance and displacement of the particle will be the same.
• Therefore, option A is the correct answer.