Which of the following examples illustrates static friction?

A box sits stationary on a ramp.

A ball rolling on the lawn eventually comes to rest.

A car rounds a curve on a road.

A fish swims upstream.

A box sits stationary on a ramp

Explanation:

Static friction is a force which keeps an object at rest as it is in the case of the box. It has to be overcome for the object to be set into motion.

Static force of friction is calculated as follows:

F = μη

F is static force of friction.

μ is the coefficient of static friction.

η is the normal force.