Answer:
1002.2688 m/s
Explanation:
g = Acceleration due to gravity = 9.81 m/s²
h = The length of a string = 2 m
m = Mass of block = 1.6 kg
[tex]m_2[/tex] = Mass of bullet = 0.01 kg
Here, the potential energy of the fall will balance the kinetic energy of the bullet
[tex]mgh=\dfrac{1}{2}mv^2\\\Rightarrow v=\sqrt{2gh}\\\Rightarrow v=\sqrt{2\times 9.81\times 2}\\\Rightarrow v=6.26418\ m/s[/tex]
Velocity of block is 6.26418 m/s
As the momentum of system is conserved we have
[tex]mv=m_2u\\\Rightarrow u=\dfrac{mv}{m_2}\\\Rightarrow u=\dfrac{1.6\times 6.26418}{0.01}\\\Rightarrow u=1002.2688\ m/s[/tex]
The magnitude of velocity just before hitting the block is 1002.2688 m/s