How does the length of a wire affect its resistance?

You can think of a long wire as several resistors in series together. In a series circuit, to find the total resistance you add the resistance of each resistor together. The more resistors you have the greater the total resistance. Likewise the longer the wire the greater the resistance. In a parallel circuit, the more resistors you have in parallel the more the resistance decreases, because it increases the number of pathways for the electricity to flow. This would be similar to increasing the diameter of a single piece of wire. The greater the diameter the lower the resistance.

The length of a wire is directly proportional to the wires resistance. This is because the current, which is a flow of electrons, will collide more frequently with the positive charged metal ions, as there will be a higher number of them in a larger cross sectional area

Well the longer the wire the more collisions the electrons will have with the atoms in the way from one end of the wire to the other. Therefore the resistance will increase as the length increases. Also there is a formula which relates resisitance to length - other factors being kept constant - and the relationship can be seen through this formula as well.

The resistance is directly proportional to the length of the wire, the longer the wire the greater the resistance.

The longer the length of wire, the greater the resistance. This is because there will be more collisions with the metal ions by the flowing electrons. This can be demonstrated in the equation resistance = resistivity x length / area. Resistance is directly proportional to length.

You can think of a long wire as several resistors in series together. In a series circuit, to find the total resistance you add the resistance of each resistor together. The more resistors you have the greater the total resistance. Likewise the longer the wire the greater the resistance. In a parallel circuit, the more resistors you have in parallel the more the resistance decreases, because it increases the number of pathways for the electricity to flow. This would be similar to increasing the diameter of a single piece of wire. The greater the diameter the lower the resistance.