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NEET PHYSICSWORK, ENERGY AND POWERMedium

Question

A bomb of 12 kg12 \text{ kg} explodes into two pieces of masses 4 kg4 \text{ kg} and 8 kg8 \text{ kg}. The velocity of 8 kg8 \text{ kg} mass is 6 m/sec6 \text{ m/sec}. The kinetic energy of the other mass is:

A

48 J48 \text{ J}

B

32 J32 \text{ J}

C

24 J24 \text{ J}

D

288 J288 \text{ J}

Step-by-Step Solution

According to the law of conservation of linear momentum, the total momentum of an isolated system remains constant. Since the bomb is initially at rest, its initial momentum is zero . Let the mass of the first piece be m1=8 kgm_1 = 8 \text{ kg} and its velocity be v1=6 m/s\vec{v}_1 = 6 \text{ m/s}. Let the mass of the second piece be m2=4 kgm_2 = 4 \text{ kg} and its velocity be v2\vec{v}_2. Initial momentum=Final momentum\text{Initial momentum} = \text{Final momentum} 0=m1v1+m2v20 = m_1\vec{v}_1 + m_2\vec{v}_2 0=(8×6)+(4×v2)0 = (8 \times 6) + (4 \times \vec{v}_2) 4v2=484\vec{v}_2 = -48 v2=12 m/s\vec{v}_2 = -12 \text{ m/s} The negative sign indicates that the second piece moves in the opposite direction . The kinetic energy (KK) of the second mass (m2m_2) is given by: K=12m2v22K = \frac{1}{2}m_2v_2^2 K=12×4×(12)2K = \frac{1}{2} \times 4 \times (-12)^2 K=2×144=288 JK = 2 \times 144 = 288 \text{ J}

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.

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