The Science of NFL Football Newtons 1 st

The Science of NFL Football

Newton’s 1 st Law of Motion Inertia n n n Why do objects sometimes not move? Why do objects sometimes move with constant velocity? Why do object sometimes accelerate?

Newton’s First Law - Inertia n n An object will remain at rest or in motion with a constant velocity unless acted on by an external net force. Fine Points ¡ Two natural states of “motion” n ¡ At Rest OR Constant Velocity External, Net Force results in other motion n Acceleration

Underlying Concepts of Inertia Do objects have inertia because of mass, weight, friction? n Mass - quantity of matter in an object measured by its resistance to a change in its motion (inertia)

Mass vs Weight n n Which one changes when you change elevation on the earth…or go to the Moon? Why? Is your weight constant on earth? How do you convert back and forth between the two? If you pushed/lifted a mass on earth then on the moon, what would be the same? What would be different?

Newton’s 1 st Law and Everyday Experience Use Newton’s 1 st Law to explain the how and why of… 1. 2. 3. 4. 5. 6. getting snow out of the crevices of your boots? why many automobile passengers experience neck injuries when struck by a car from behind? what happens to the books on the passenger seat of your car when you slam on your breaks? getting raindrops off an umbrella before coming indoors? the best way to escape from a rampaging elephant? how to tighten a loose hammer head?