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Wednesday February 1st. Sir Isaac Newton’s Laws: First and Second Laws of Motion. Okay! So what are we doing today?. Content Objective : Students will be able to summarize the three laws of motion.
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Wednesday February 1st Sir Isaac Newton’s Laws: First and Second Laws of Motion
Okay! So what are we doing today? • Content Objective: Students will be able to summarize the three laws of motion. • Literacy Objective: Students will be able to define inertia as the tendency of an object to resist a change in its motion
First Law of Motion • The First Law of Motion states that if the net force acting on an object is zero, the object doesn’t change its motion • If it’s at rest – it stays at rest • If it’s moving – it keeps moving • Only Unbalanced forces change an object’s velocity
Does anyone here HATE change? • You like things the way they are and you don’t want to change them? • In humans this iscalled being stubborn • In objects this is calledinertia
Inertia • Inertia is the tendency of an object to resist change in its motion • ALL OBJECTS HAVE INERTIA, whether they are moving or not • Inertia means objects hate change • The heavier and object, the more it resists change • Imagine stopping a sumo wrestler running at you vs. stopping a horse jockey running at you
What happens in a car crash? • Let’s test it out with my dear friend, Winnie the Pooh!
Second Law of Motion • Second Law of Motion – the acceleration of an object is in the same direction as the net force on the object • (whichever way the net force is pointing, that’s the direction the object moves) • Force = Mass * Acceleration (F = ma)
Third Law of Motion • Third Law of Motion: for every action there is an opposite and equal reaction • A good example is jumping on a trampoline • http://www.youtube.com/watch?v=TK27aknWVI4
So let’s review the 3 laws: • First Law: An object in motion tends to stay in motion, an objet at rest tends to stay at rest (unless acted upon by an unbalanced force) • Second Law: F=m*a, i.e. it takes more force to move a heavier object the same distance • Third Law: For every action there is an opposite and equal reaction
Visual Review of 3 Laws • http://www.youtube.com/watch?v=cP0Bb3WXJ_k