The initial kinetic energy of the boat and its rider is

After Sam stops it, the final kinetic energy of the boat+rider is

because its final velocity is zero.
For the law of conservation of energy, the work done by Sam is the variation of kinetic energy of the system:

where the negative sign is due to the fact that the force Sam is applying goes against the direction of motion of the boat.
Answer:
As much wood as a woodchuck could chuck, If a woodchuck could chuck wood.
Explanation:
O.99 m long .simple pendulum time period is 2s for second formula then use formula T=2pi.rt(lenght/gravity)
Ozone in troposphere is also know as Bad Ozone, Evil Ozone and Ground Level Ozone.
F = q₁q₂C / r²
F force
q charge
C Coulomb constant
r separation between charges