NEWTON’S LAWS OF MOTION

Sir Isaac Newton  Born Jan. 4, 1643 in England.  As a young student, Newton didn’t do well in school.  He worked hard and continued his education.  Later in life, Newton contributed ideas that became law in the worlds of science and math.

Force  A push or a pull  Measured in Newtons: a force of 10N Net Force: the sum of all forces acting on an object ? 0 ? 10N 5 N 3 N 12 N

Types of Forces  Gravity - acceleration of gravity of any object is 9.8 m/s 2  Friction: force that resists motion between two surfaces in contact - the force that will work against motion in any situation

Balanced vs. Unbalanced  An unbalanced force (net force) acting on an object changes its speed and/or direction of motion. - object moves with the greater force  With a balanced force, an object will not accelerate OR will remain at a constant speed

Newton’s First Law of Motion  “An object at rest tends to stay at rest and an object in motion tends to stay in motion with the same speed and in the same direction unless acted upon an outside unbalanced force.”

Newton’s 1 st law = Inertia  Inertia - the resistance to changes in motion. - inertia is proportional to mass. - big masses resist changing their motion more than smaller masses. A lot of inertia! The large train resists changing its motion. Very little inertia. The small baby carriage has very little resistance to changes in motion.

Newton’s Second Law of Motion

Another words……  Acceleration is directly related to: - to the size of force AND in the same direction as the force Large force, Large acceleration small force, small acceleration  Acceleration is inversely related to - mass of the object Large mass, small acceleration small mass, Large acceleration

Newton’s Third Law of Motion  "For every action, there is an equal and opposite reaction." Reaction Action