Answer:
0.07142 m/s in the opposite direction of the bullet
Explanation:
[tex]m_1[/tex] = Mass of rifle = 70 kg
[tex]m_2[/tex] = Mass of bullet = 0.01 kg
[tex]v_1[/tex] = Velocity of rifle
[tex]v_2[/tex] = Velocity of bullet = 500 m/s
As the momentum of the system is conserved
[tex]m_1v_1+m_2v_2=0\\\Rightarrow v_1=-\frac{m_2v_2}{m_1}\\\Rightarrow v_1=-\frac{0.01\times 500}{70}\\\Rightarrow v_1=-0.07142\ m/s[/tex]
The recoil velocity of the rifle is -0.07142 m/s
The negative sign shows the opposite direction of the rifle.