Why can't forces be seen

Force and types of force

Graphic representation of a force by an arrow (vector)

The three factors of magnitude, direction and point of application are decisive for the effect of a force. This can be drawn very easily with a so-called Power arrow represent:

  • The length of the arrow symbolizes the amount of force. If you agree on a scale (e.g. \ (1 \, \ rm {cm} \) corresponds to \ (1 \, \ rm {N} \)) (\ (1 \, {\ rm {cm}} \ buildrel \ wedge \) over = 1 \, {\ rm {N}} \)), the amount can be read immediately from the drawing. With the chosen drawing unit, an amount of force of approx. \ (5 \, \ rm {N} \)) would result.
  • The direction of the arrow (for a given point of application mainly indicated by the tip of the arrow) determines the direction of the force.
  • The base or starting point of the arrow (and not the tip, this is a common mistake made by students) is the point of attack.

The straight line that can be drawn through the power arrow is often called Line of action designated.

Note: In physics there are a number of quantities for which the direction is important. These sizes are also called Vectors. Examples are the speed, the acceleration and the force. In contrast to this, there are physical quantities that are not direction-dependent; these are referred to as Scalars. Examples here are time, mass and electrical charge.