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NEET PHYSICSWORK, ENERGY AND POWERMedium

Question

Given below are two statements: Assertion (A): When a firecracker (rocket) explodes in mid-air, its fragments fly in such a way that they continue moving in the same path, which the firecracker would have followed, had it not exploded. Reason (R): The explosion of cracker (rocket) occurs due to internal forces only and no external force acts for this explosion.

A

Both (A) and (R) are True and (R) is the correct explanation of (A).

B

Both (A) and (R) are True but (R) is not the correct explanation of (A).

C

(A) is True but (R) is False.

D

(A) is False but (R) is True.

Step-by-Step Solution

  1. Analyze Assertion (A): When a projectile like a firecracker explodes in mid-air, the fragments fly off in different directions with varying velocities. It is the centre of mass of the fragments that continues to move along the same parabolic path that the firecracker would have followed if it had not exploded, not the fragments themselves. Therefore, Assertion (A) is False [Class 11 Physics, Ch 6, Sec 6.4, Fig 6.12].
  2. Analyze Reason (R): An explosion is caused by chemical reactions releasing energy, which involves internal forces within the system. While gravity (an external force) continues to act on the system, the explosion event itself is driven by internal forces, and internal forces cannot change the trajectory of the centre of mass. Therefore, Reason (R) is True.

Exam Context & Concepts Covered

This question aligns with the NEET PHYSICS syllabus, specifically targeting concepts from WORK, ENERGY AND POWER. Mastering this topic is crucial for scoring well in the upcoming medical entrance examinations. Solving conceptually related problems will help you understand the nuances of these concepts and improve your problem-solving speed.

PHYSICSWORK, ENERGY AND POWERstatementsassertionfirecrackerrocketexplodes

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