Transcript Chapter 5 Newton’s Second Law of Motion – Force and

Chapter 5
Newton’s Second Law of Motion –
Force and Acceleration
Acceleration =
change in velocity
Time Interval
• Net force – combination of all forces acting on an object
• Acceleration depends on net force
• If the net force on an object is 0. The object will stay at rest
or stay at a constant velocity (Newton’s First Law)
• If there is a net force acting on an object that is greater than
zero, it will experience an accleration
• The acceleration of an object is directly proportional to the
net force:
acceleration ~ net force
Acceleration =
Acceleration =
____1____
mass
____net force____
mass
a=
F
M
Friction
There are several different kinds of friction:
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Static Friction
Sliding Friction
Rolling Friction
Fluid Friction
We will only focus on Static Friction and Sliding Friction
• Static Friction – is the friction between two
surfaces in contact with each other if they are
at rest (FS)
• Sliding Friction – is the friction between two
surfaces in contact with each other if they are
moving (FK)
F f = μ x FN
• The normal force (support force) will always
act perpendicular to surface in contact: