Answer:
final velocity of fisherman will be 1.744 m /sec in west direction
Explanation:
We have given mass of the fisherman [tex]m_1=81kg[/tex]
Velocity of fisherman [tex]v_=-4.5m/sec[/tex] ( As east direction is positive direction )
Mass of the rowboat [tex]m_2=128kg[/tex]
As the rowboat is at rest so [tex]v_2=0m/sec[/tex]
Now according to conservation of momentum
[tex]m_1v_1+m_2v_2=(m_1+m_2)v[/tex]
[tex]81\times -4.5+128\times 0=(81+128)\times v[/tex]
[tex]v=-1.744m/sec[/tex]
So final velocity of fisherman will be 1.744 m /sec in west direction