7. Friction, Inclines, Systems

A block $1$ rests on a horizontal surface and is connected by a light string over a frictionless pulley to a hanging block $2$. If block $2$ is heavier and tends to pull block $1$ to the right, in which direction does the static friction force act on block $1$?

Which of the following best describes the difference between $f\_\mathrm{static}$ (static friction) and $f\_\mathrm{kinetic}$ (kinetic friction)?

When you walk across a carpet and then touch a metal object, you often feel a shock. Which of the following best explains this phenomenon in terms of static friction?

Which type of friction is generally more difficult to overcome when starting to move an object at rest on a surface?