a nucleus of 210 Po 84 originally at rest emit alpha particle with speed v .What is the recoil speed of the daughter nucleus? Share with your friends Share 9 Ved Prakash Lakhera answered this The mass of polonium=210The mass of daughter nucleus after α particle is emitted=210-4=206.Initial momentum=0Let speed of daughter nucleus be v'.Applying law of conservation of momentum, we get, 0 = 206 v'+4 vor v' =- 4 v/206=-2 v/103. 29 View Full Answer