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प्रश्न
A uranium-238 nucleus, initially at rest, emits an alpha particle with a speed of 1.4 × 107m/s. Calculate the recoil speed of the residual nucleus thorium-234. Assume that the mass of a nucleus is proportional to the mass number.
उत्तर
According to the question, uranium 238 nucleus emits an alpha-particle with a speed of 1.4 × 107 m/s.
Let the speed of the residual nucleus thorium 234 be v2.
By the law of conservation of linear momentum, we have:
Here, m1 and v1 are the mass and velocity of the alpha-particle repectively, and m2 is the mass of the residual nucleus.
Therefore, the speed of the residual nucleus is
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