Answer:
frictional
Step-by-step explanation:
This scenario follows Newton's third law of motion which alludes to the fact that for every force or action exerted by a person on a body there is an equal and opposite reaction exerted back.
Because there is a limited frictional force (a force exerted by an object when an object moves across it) between
- the canoe and
- water surface (the opposite force/reaction)
Here, the paddle helps the boatman apply a force on the water, resulting in the opposite amount of force been sent back; pushing the boat forward.