Answer:
a) v=1.81 m/s; B) v=4.95 m/s
Explanation:
using momentum conservation
m1v1+m2v1=m1v2+m2v2
A)
5.2*672+700*0=5.2*428+700v2
The initial velocity of the block is 0, solving for v2
v2=1.81 m/s
B) Now both the bullet and the block travel together
m1v1+m2v1=(m1+m2)v2
5.2*672+700*0=(5.2+700)v
v=4.95 m/s