why do paddles/oars have a large surface area? I thought that it does not really matter as i would just apply a force on the water so as to attain a action-reaction force on the boat thus pushing me forward. but if i look at the free body diagram of the paddle 1 force will be me pushing and the other (opposing) is water resistance. But ultimately i will have a greater pushing force to push the paddle back so the reaction force will push the boat forward. but that is the net force of the paddle, i don't think action and reaction pairs are based on the net force of object rather they are based on the integral forces in the particular system. So, i'm confused about this newton's third law and also how the larger surface area will give more force to push the boat forward. Thanks for the help!