Question

Kinetic friction is less than the limiting static friction because once an object is moving, there are fewer points of contact, and the friction is reduced. For this reason, more force is needed to start moving an object than to keep it in motion.

a) True.

b) False.

Answer 1

Kinetic friction is indeed less than limiting static friction due to fewer contact points once an object is in motion, which is why it is easier to keep an object moving than to start its motion.

Step-by-step explanation:

The question asks if kinetic friction is less than limiting static friction and the explanation provided states that it is true because once an object is in motion, there are fewer points of contact, which reduces friction. This phenomenon explains why more force is required to start an object moving than to keep it in motion.

When attempting to move a stationary object, such as pushing a heavy crate on a concrete floor, you encounter static friction, which increases to match your push until the motion starts. Once the crate is moving, you face kinetic friction, which is less forceful than static friction. If you were to add mass to the crate or apply a lubricant like oil, the static friction would increase and decrease, respectively, but the kinetic friction would follow suit albeit remaining less than the new static friction values.