Answer: 6.21 m/s opposite to Janet
Explanation:
Given
mass of Janet [tex]m_j=59\ kg[/tex]
mass of Sarah [tex]m_s=32\ kg[/tex]
The initial velocity of Janet [tex]u_1=7\ m/s[/tex]
The final velocity of Janet after the collision is [tex]v_1=2\ m/s[/tex]
the final velocity of Sarah after the collision is [tex]v_2=3\ m/s[/tex]
Conserving linear momentum
[tex]\Rightarrow m_ju_1+m_su_2=m_jv_1+m_sv_2\\\Rightarrow 59\times 7+32\times u_2=59\times 2+32\times 3\\\Rightarrow 32u_2=118+96-413\\\Rightarrow u_2=\frac{-199}{32}=-6.21\ m/s[/tex]
Negative indicates the direction of velocity is opposite than of Janet
