Question

Look at the graphs (a) to (d) in the following figure carefully and state, with reasons, which of these cannot possibly represent one-dimensional motion of the particle.

Answer 1

None of the four graphs can represent one-dimensional motion of the particle. In fact, all the four graphs are impossible.

1. A particle cannot have two different positions at the same time.

2. A particle cannot have velocity in opposite directions at the same time.

3. Speed is always positive (non-negative).

4. Total path length of a particle can never decrease with time.

Note: The arrows on the graphs are meaningless.