A bomb is kept stationary at a point. It suddenly explodes into two fragments of masses 1 g and 3 g. The total K.E. of the fragments is 6.4 x 10⁴ J. What is the K.E. of the smaller fragment?
The term “stationary” refers to an object that is not in motion and remains in a fixed position relative to a specific reference point. In physics, stationary objects can be analyzed in terms of forces acting upon them, equilibrium conditions and their potential energy. Understanding stationary objects is crucial for various applications, including mechanics, engineering, and motion analysis.
Class 11 Physics focuses on Chapter 5, which covers the concepts of work, energy, and power. This chapter explores the definitions and relationships between these fundamental concepts, emphasizing their significance in mechanical systems. Students learn how to calculate work done by forces, understand different forms of energy and analyze power in various contexts. The knowledge gained in this chapter is essential for understanding broader physical principles and their applications in real-world scenarios, preparing students for the CBSE Exam.
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A stationary bomb breaks into two fragments with masses of 1 gram and 3 grams upon explosion. According to reports, the total kinetic energy of the fragments after the explosion is 64,000 joules. In this case, the kinetic energy of the lighter fragment can be found by taking into account principles from the law of conservation of momentum and that relating mass with kinetic energy.
In a system in which two objects collide or separate, the total momentum before and after the event is constant provided no external forces act on them. In this case, because the bomb was stationary before it exploded, the total momentum was zero, so the momentum of the fragments has to balance out after the explosion.
We know that the kinetic energy is distributed between the two fragments based on their respective masses, as deduced from the mass ratio of the fragments. The smaller fragment will have a proportionately smaller amount of kinetic energy compared to the larger fragment. Therefore, we can say that the kinetic energy of the smaller part will be 48,000 joules, and that of the larger part is going to be the rest after the explosion. Such a process explains how the principles of mass, momentum, and kinetic energy work hand in hand in an explosion.
For more information:
https://www.tiwariacademy.com/ncert-solutions/class-11/physics/chapter-5/