# NCERT Class 11 Physics Solutions: Chapter 3 – Motion in a Straight Line Part 9

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Question: 3.17

Below figure shows the plot of one-dimensional motion of a particle. Is it correct to say from the graph that the particle moves in a straight line for and on a parabolic path for? If not, suggest a suitable physical context for this graph.

• No. The x-t graph of a particle moving in a straight line for and on a parabolic path forcannot be shown as the given graph.

• This is because, the given particle does not follow the trajectory of path followed by the particle as

• A physical situation that resembles the above graph is of a freely falling body held for sometime at a height

Question 3.18:

A police van moving on a highway with a speed of fires a bullet at a thief’s car speeding away in the same direction with a speed of. If the muzzle speed of the bullet is with what speed does the bullet hit the thief’s car? (Note: Obtain that speed which is relevant for damaging the thief’s car).