A uranium nucleus (mass 238 units) at rest decays into a helium nucleus (mass 4.0 units) and a thorium nucleus (mass 234 units). If the speed of the helium nucleus is 1.8 * 10⁶ m/s, what is the speed of the thorium nucleus? A) 1.0 *10⁴ m/s B) 3.1 * 10⁴m/s C) 3.6* 10⁴ m/s D) 4.1 *10⁴ m/s

Question

Quizplus · Accepted Answer

Using conservation of momentum, the momentum of the helium nucleus equals the momentum of the thorium nucleus. Solving for the speed of the thorium nucleus gives approximately 3.1 x 10^4 m/s.

A Uranium Nucleus (Mass 238 Units) at Rest Decays into a Helium