Formula for friction

Here are the formulas for friction:

• Static Friction ($f_s$): This is the force that opposes the initiation of motion. It can vary up to a maximum value.

  $$f_s \le \mu_s N$$

  where:

  • $f_s$ is the static friction force
  • $\mu_s$ is the coefficient of static friction
  • $N$ is the normal force

• Kinetic Friction ($f_k$): This is the force that opposes motion when an object is sliding.

  $$f_k = \mu_k N$$

  where:

  • $f_k$ is the kinetic friction force
  • $\mu_k$ is the coefficient of kinetic friction
  • $N$ is the normal force