The coefficient of static friction between a 2.5 kg block and a rough surface is .80. what is the maximum static frictional force that can act on the block.

19.6 N

Explanation:

Static friction is a force that keeps an object at rest.Once an object exceed the maximum limit of it , it starts moving

If a small amount of force is applied to an object, the static friction has an equal magnitude in the opposite direction.

If the force is increased, at some point the value of the maximum static friction will be reached, and the object will start moving.

force of static friction = (coefficient of static friction) * (normal force)

Fmax = μ R

Fmax = μ R  = μ mg   (where g = 9.8 ms⁻²)

         = 0.80 * 2.5 * 9.8

         = 19.6 N

the body's situation won't change the forces are equal opposit and on the same body