The work that Sam should do in order to stop is the boat is the same as that of the kinetic energy of the object in order to counter its motion. Kinetic energy is calculated through the equation,
KE = 0.5mv²
where KE is kinetic energy, m is mass, and v is the velocity.
Substituting,
KE = 0.5(1200kg)(1.2 m/s)²
<em>KE = 864 J</em>
