Isaac Newton's first law of motion, also known as the law of inertia , states that an object at rest will stay at rest and an object in motion will stay in motion with the same speed and direction unless acted upon by unbalanced force.
It requires more force to start the motion from rest.
#color(green)("It is called "INERTIA".#
#color(blue)("Objects with greater mass have more inertia"#
Once started moving, requires less force to continue the motion.