Question

what do the length and direction of a vector represent in a force - body diagram?
the length shows the type of force, and the direction shows the forces location on the object.
the length shows the strength (magnitude) of the force, and the direction shows the direction in which the force acts.
the length shows the speed of the object, and the direction shows the path the object will take.
the length shows how long the force lasts, and the direction shows the forces source.

Explanation:

In physics, a vector represents a quantity with both magnitude and direction. For a force - vector, the length of the vector represents the strength (magnitude) of the force, and the direction of the vector shows the direction in which the force acts.

Answer:

The length shows the strength (magnitude) of the force, with the direction shows the direction in which the force acts.