Vectors Representing Forces

A force can be represented by a vector (drawn as an arrow). The arrow's length is related to the size of the force and the arrow's direction shows you the direction of the force. If you have a stalled car and you are pushing on the back bumper with 200 Newtons of force, you show that force as an arrow pointing in the direction the car would move from your pushing.

If instead, you were pulling an elephant with 100 Newtons on his harness,  you could show the force as an arrow (1/2 the length of the one pushing the car) in the direction you are trying to lead the elephant. If a mouse runs by and the elephant pulls back with 1000 Newtons of force that could be shown by an arrow (10x longer than your pulling force vector and pointing in the opposite direction) in the direction that the elephant is trying (and most likely succeeding) to move. The arrows can be drawn anywhere along the line connecting the elephant and you.