A nucleus ZXA emits an α-particle with velocity v. The recoil speed of the daughter nucleus is 

A nucleus ZXA emits an α-particle with velocity v. The recoil speed of the daughter nucleus is  Correct Answer <span class="math-tex">\(\frac{{4v}}{{A - 4}}\)</span>

CONCEPT:

  • Linear Momentum: The product of the mass and velocity of an object is called linear momentum.

p = mv

where p is linear momentum, m is mass of the body and v is the velocity.

  • Law of conservation of momentum: the law of conservation of momentum states that the total momentum of an isolated system remains constant.

pi = pf

where pf is final linear momentum and pi is initial linear momentum.

CALCULATION:

Given that initially, ZXis at rest so, vi = 0

speed of α = v

Let the α particle decay equation is

ZX—→ Z-2YA-4  + 2α4

where Y is the daughter nucleus.

and vy is the velocity of the daughter nucleus.

By Principle of momentum conservation

p= pf

miv= mfvf

0 = (A-4) vy - 4 v

Recoil speed (vy) = 4v/(A-4)

So the correct answer is option 2.

Related Questions

If m, mn and mp are the masses of nucleus, neutron and proton respectively of ZXA nucleus, then: