Given that block of mass m1 = 3kg and mass m2 = 2kg are present with initial velcities, u1 and u2 equals to 0 as there are at rest.
A bullet of mass m=0.02 kg strikes with the block and embeds into the second block.
After this, speed of block 1 is v1= 2m/s and speed of bullet+block2 is v2= 5m/s
According to conservation of momentum,
[tex]m1\times u1+m2\times u2+m\times u=m1\times v1+(m2+m)v2[/tex]
Here, u is the initial velocity of bullet,
Substituting the values, we get
[tex]3\times0+2\times0+0.02\times\text{ u = 3}\times2+(2+0.02)\times5[/tex]
[tex]\begin{gathered} u=\frac{16.1}{0.02} \\ =805\text{ m/s} \end{gathered}[/tex]
Thus, the initial speed of bullet is 805 m/s