Chapter 13 Motion

Table of Contents 13-1 What are Motion and Speed? 13-2 What are velocity and acceleration? 13-3 What is momentum? 13-4 What is Newton’s First Law of Motion? 13-5 What is Newton’s Second Law of Motion? 13-6 What is Newton’s Third Law of Motion?

13-1 What are Motion and Speed? Motion-a change in the position relative to some fixed object or place  Speed = distance  time Example; Boat traveling 120 km in 4 hours has what speed?   To calculate speed, distance or time, solve algebraically or use the triangle method: v x t d Table of Contents

Answer Speed = 120 km  4 hours Speed = 30 km/hr Triangle Method… V x 4 hr 120 km Table of Contents Back to notes

13-1 What are Motion and Speed? (continued) Average Speed = total distance  time   Velocity- the same as speed, but also tells the direction (same formula) example;90 km/hour west (velocity) 90 km/hour (speed) Table of Contents

13-2 What are velocity and acceleration? Acceleration – a change in velocity Formula for acceleration: Acceleration = change in velocity  time   Acceleration = final velocity - initial velocity Time A = Vf - Vi T If the object is at rest before it accelerates, the initial velocity is 0. If the object comes to a stop, the final velocity is 0. -Sometimes acceleration can be negative…. This is called deceleration. Table of Contents

13-2 What are velocity and acceleration? (continued) Example; If a wolf is sitting next to a log and chases after a turkey, which took 10 seconds……what was his acceleration if when he caught the turkey the wolf’s velocity was 28 m/sec.? A = 28 m/sec - 0 10 sec A =2.8 m/sec/sec or m/sec2 Table of Contents

13-3 What is momentum? Momentum = mass x velocity Example; If a football player is running 8 m/sec and has a mass of 300 kg, what is his momentum? Answer = 2400 kg-m/sec Table of Contents

13-3 What is momentum? (continued) Law of Conservation of Momentum- in any isolated system, momentum can be transferred but cannot be lost. Table of Contents

13-4 What is Newton’s First Law of Motion? An object in motion will remain in motion, an object at rest will remain at rest unless acted on by an outside force. Also known as inertia. Examples; moving car taking a sharp turn, roller coaster at top of hill, person in car accident without seatbelt on, pulling table cloth off with table set. Video of 1st Law of Motion Table of Contents

13-5 What is Newton’s Second Law of Motion? Force = Mass x Acceleration F = M x A One Newton (N) is the force needed to accelerate a one kg mass to an acceleration of 1 m/sec/sec Example; If there were no friction, what force would be needed to accelerate a 5-kilogram mass 20 m/sec/sec? Answer = 100 N Video of 2nd Law of Motion Table of Contents

13-6 What is Newton’s Third Law of Motion? For every action there is an equal and opposite reaction. Examples; rocket blasting off, balloon being released, tennis racket and ball Video of 3rd Law of Motion Table of Contents