Question

90. An uranium nucleus (at rest) undergoes fission and splits into two fragments, one heavy and the other light. Which fragment is moving faster after the fission?

Answer 1

Step-by-step explanation:

No external force is acting on uranium nucleus so we can apply law of conservation of momentum . If M and m be the mass of bigger and smaller fragments respectively and V and v be their velocity after fission , Total momentum after fission = total momentum before fission

MV - mv = 0 , since the nucleus was at rest , its momentum before fission is zero . negative sign of mv is taken because smaller fragment will move in opposite direction to that of bigger fragment .

MV = mv

M / m = v / V

M > m

Hence,

v > V

So velocity of smaller fragment will be higher .