6.5.4.2 Forces, accelerations and Newton's Laws of motion
What you need to know
State Newton's First Law, identifying that a stationary object remains stationary, and a moving object continues moving at the same velocity, if the resultant force is zero.
Understand that a vehicle travelling at a steady speed implies balanced resistive and driving forces.
Conclude that an object's velocity (speed and/or direction) changes if and only if a resultant force is acting on it.
Apply Newton's First Law to accurately explain the motion of objects moving with a uniform velocity and objects undergoing changes in speed or direction.
(HT only) Define inertia as the innate tendency of objects to continue in their state of rest or of uniform motion.
