Task: Text Categorization
Input (English): This force is represented by a first derivative with respect to position in the harmonic oscillator equation. In one model, this force stems from tiny electrostatic repulsions. It can be understood as the parallel shear component of the contact force, whose other component is typically calculated as mg cosine theta. It is calculated from a coefficient, symbolized mu, multiplied by the normal force. Rolling motion is affected by the "kinetic" type of this force, which is known as "drag" in fluids. For 10 points, name this force that resists the motion of objects against one another.
Output (English): Science