氡核经过α衰变后放出钋原子,氡的质量数222.质子数86,质量为M,阿尔法粒子质量为m,已知是方的何能全部转化为钋和α粒

mv+m(po)v(po)=0.1
E=1/2*mv^2+1/2*m(po)v(po)^2.2
1+2
E=mv+m(po)v(po)+1/2*mv^2+1/2*m(po)v(po)^2
E=(mv)^2/2m+(m(po)v(po))^2/2m(po)..3
由1
(mv)^2=(m(po)v(po))^2
所以
3即为
(mv)^2×（m+mpo)/2m*mpo=E
E/(mv)^2=（m+mpo)/2m*mpo=55.5/109m
E=55.5/109m *(mv)^2=55.5mv^2/109=(M-mpo-m)c^2