Conservation of momentum:
m1*v1+ m2*v2 = (m1+m2) v
mass 1 = m1= 1.95 kg
mass 2 = m2= 0.64 kg
initial velocity 1 = v1= 29 m/s
initial velocity 2 = v2= 7.5 m/s
v= final speed
Replacing:
(1.95*29)+(0.64*7.5) = (1.95+0.64)v
Solve for v
56.55+ 4.8 = 2.59 v
61.35=2.59v
61.35/2.59=v
v= 23.687 m/s