ANSWER:
46.08 kg
STEP-BY-STEP EXPLANATION:
Given
m1 = 1152 kg
v1 = 0.06 m/s
v2 = -1.5 m/s
We apply law of conservation of linear momentum:
[tex]\begin{gathered} P_i=P_f \\ P_i=0 \\ P_f=m_1\cdot V_1+m_2\cdot V_2 \end{gathered}[/tex]We plug in and calculate for the mass, just like this:
[tex]\begin{gathered} 0_{}=m_1\cdot V_1+m_2\cdot V_2 \\ 0=1152\cdot0.06+m_2\cdot-1.5 \\ -1.5m_2=-69.12 \\ m_2=\frac{-69.12}{-1.5} \\ m_2=46.08\text{ kg} \end{gathered}[/tex]Which means that the mass of the pianist is 46.08 kg