def resistance(self):
self.total_resistance_coef = frictional_resistance_coef(self.length, self.speed) +residual_resistance_coef(self.slenderness_coefficient,<EOL>self.prismatic_coefficient,<EOL>froude_number(self.speed, self.length))<EOL>RT = <NUM_LIT:1> / <NUM_LIT:2> * self.total_resistance_coef * <NUM_LIT> * self.surface_area * self.speed ** <NUM_LIT:2><EOL>return RT<EOL>
Return resistance of the vehicle.

:return: newton the resistance of the ship