Answer:
0.2 m/s
Explanation:
[tex]m_A[/tex] = Mass of glider A= 0.125 kg
[tex]m_B[/tex] = Mass of glider B = 0.375 kg
[tex]u_A[/tex] = Initial Velocity of glider A = 0 m/s
[tex]u_B[/tex] = Initial Velocity of glider B = 0 m/s
[tex]v_A[/tex] = Final Velocity of glider A = 0.6 m/s
[tex]v_B[/tex] = Final Velocity of glider B
As linear momentum is conserved
[tex]m_{A}u_{A}+m_{B}u_{B}=m_{A}v_{A}+m_{B}v_{B}\\\Rightarrow v_B=\frac{m_{A}u_{A}+m_{B}u_{B}-m_{A}v_{A}}{m_{B}}\\\Rightarrow v_b=\frac{0+0-0.125\times 0.6}{0.375}\\\Rightarrow v_b=-0.2\ m/s[/tex]
Magnitude of the glider B at this time is 0.2 m/s