Transcript Newton’s Laws - Bremen High School District 228 / Overview

Newton’s Laws
Newton’s First Law
• An object moving at a
constant velocity keeps
moving at that velocity
unless acted upon by an
unbalanced net force
Newton’s First Law
Continued…
• An object at rest remains at
rest unless acted upon by
an unbalanced net force
• How does a seatbelt relate
to Newton’s First Law?
•
http://www.youtube.com/watch?v=4NQbeZ0EXZQ&list=PL0CDAF675CAEE090B&index=8
Newton’s Second Law
• The acceleration of an
object is in the same
direction as the net force on
the object
Force
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Force = Mass x Acceleration
F=ma
Force is measured in Newtons (N)
You push a friend sitting on a swing. She
has a mass of 50 kg and accelerates at a
rate of 4 m/s2. Find the force you exerted.
F = 50kg x 4 m/s2 =
F = 200 N
Force Videos
•
FSN Force - http://www.youtube.com/watch?v=A_wnt84iyMk
•
NFL Impact - http://www.wired.com/wiredscience/2010/11/espn-sport-science-oncollisions-video-break-down
Centripetal Force
• The net force exerted toward
the center of a curved path
• Ex: Bucket of Water,
Earth and Moon
•
http://www.youtube.com/watch?v=bWiVv--OTYA
Newton’s Third Law
• “To every action force there is
an equal and opposite reaction
force”
Action and Reaction
• For every action there is an
equal and opposite reaction.
Action and Reaction
Forces Don’t Cancel
Momentum
• Related to how much force is
needed to change its motion
p=mv
p  momentum (kg∙m/s)
m  mass (kg)
v  velocity (m/s)
Law of Conservation
of Momentum
• The momentum of an object
doesn’t change unless its
mass, velocity, or both change
•
Bill Nye - Momentum
– http://www.youtube.com/watch?v=y2Gb4NIv0Xg