What is a force and what tools can we use to measure it?

Force can be defined several ways:

• A force is a push or pull.


• Force is the capacity to do work.


• Force = mass x acceleration.


• A force is what tends to change the state of a body at rest or in motion.

Forces can be classified into two broad categories:

• 
  Contact forces: frictional forces, buoyant forces, forces from weight, and air resistance forces.

• 
  “Action-at-a-distance” forces: gravitational forces, electrostatic forces, and magnetic forces.

Forces can be measured using different tools:

• force meter


• spring balance


• spring scale


• torque wrench


• bathroom scale


• strain gauge

Force units:

The unit for force is the Newton (N). One Newton of force is the amount of force needed to accelerate 1 kilogram (kg) of mass at a rate of 1 meter/second squared (`~m/s^2` ).

Forces are vector quantities:

A vector quantity is a quantity which has both direction and magnitude.