Physics 111

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Transcript Physics 111

Chapter 5: Force and Motion I
Newton’s Laws
I.
If no net force acts on a body, then the
body’s velocity cannot change.
II. The net force on a body is equal to the
product of the body’s mass and
acceleration.
III. When two bodies interact, the forces on the
bodies from each other are always equal in
magnitude and opposite in direction.
Mass, Force and Acceleration
Unit of force: SI: newton (N), cgs: dyne
F=ma
Sample Problem 5-3
Some particular forces
Gravitational Force
Normal Force
Tension
Application
Sample problems 5-6, 5-7 and 5-8