Physics - Introduction to aceleration, projectle motion, 2nd law | part 2 скачать в хорошем качестве

Physics - Introduction to aceleration, projectle motion, 2nd law | part 2

BrightMind21    • Physics - Introduction to aceleration, pro...   3. Newton’s Second Law Newton’s Second Law of Motion: The acceleration of an object is directly proportional to the net force acting on it and inversely proportional to its mass. F ⃗ net = m a ⃗ F net ​ =m a Where: F ⃗ net F net ​ = net force (vector sum of all forces) in newtons (N) m m = mass in kilograms (kg) a ⃗ a = acceleration in m/s² Key points: Force causes acceleration, not velocity. If F net = 0 F net ​ =0 → acceleration = 0 → constant velocity (or at rest). Direction of acceleration is same as direction of net force. Mass is a measure of inertia (resistance to change in motion). Steps to apply: Identify all forces acting on the object. Find the vector sum of these forces ( F net F net ​ ) in each direction (x, y). Use F net , x = m a x F net,x ​ =ma x ​ and F net , y = m a y F net,y ​ =ma y ​ . Solve for unknowns. 4. Connection Between These Topics In projectile motion: Horizontal: F net , x = 0 ⇒ a x = 0 ⇒ v x F net,x ​ =0⇒a x ​ =0⇒v x ​ constant. Vertical: F net , y = − m g ⇒ a y = − g F net,y ​ =−mg⇒a y ​ =−g (from Newton’s 2nd law). So projectile motion is a direct application of Newton’s laws with gravity as the only force (after launch).