Question

Conservation of momentum

Answer 1

Answer: 6.21 m/s opposite to Janet

Step-by-step explanation:

Given

mass of Janet
`m_j=59\ kg`

mass of Sarah
`m_s=32\ kg`

The initial velocity of Janet
`u_1=7\ m/s`

The final velocity of Janet after the collision is
`v_1=2\ m/s`

the final velocity of Sarah after the collision is
`v_2=3\ m/s`

Conserving linear momentum

`\Rightarrow m_ju_1+m_su_2=m_jv_1+m_sv_2\\\Rightarrow 59* 7+32* u_2=59* 2+32* 3\\\Rightarrow 32u_2=118+96-413\\\Rightarrow u_2=(-199)/(32)=-6.21\ m/s`

Negative indicates the direction of velocity is opposite than of Janet