Newtons Laws

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Newtons Laws
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Example Problem

• A plane fires a bullet with an initial velocity
  of 150 m/s at an angle of 370 below the
  horizontal. The bullet lands 3 seconds later.
• Find the components of the initial velocity.
• How far does the bullet travel in the horizontal
  direction before it lands?
• How high above the (level) ground was the plane
  when the bullet was fired?
• Find the magnitude of the velocity of the bullet
  right before it hits the ground.

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Pretest 3(the crate in the snow)
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Pretest 3(the crate in the snow)
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Pretest 3(the crate in the snow)
?
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Forces(dynamics)
D
Motion(kinematics)
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Types of Forces
Noncontact Forces
Contact Forces
Pushes
Pulls
Electromagnetic
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Types of Forces
Noncontact Forces
Contact Forces
Gravitational
Pushes
Pulls
Electromagnetic
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Types of Forces
Noncontact Forces
Contact Forces
Gravitational
Pushes
Pulls
Electromagnetic
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Types of Forces
Noncontact Forces
Contact Forces
Gravitational
Pushes
Pulls
Electromagnetic
Electric
Magnetic
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Types of Forces
Noncontact Forces
Contact Forces
Gravitational
Pushes
Pulls
Electromagnetic
Electric
Magnetic
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Types of Forces
Noncontact Forces
Contact Forces
Gravitational
Nuclear
Pushes
Pulls
Electromagnetic
Electric
Magnetic
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Types of Forces
Noncontact Forces
Contact Forces
Gravitational
Nuclear
Pushes
Pulls
Electromagnetic
Tension
Electric
Magnetic
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Types of Forces
Noncontact Forces
Contact Forces
Gravitational
Nuclear
Pushes
Pulls
Electromagnetic
Tension
Electric
Magnetic
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Types of Forces
Noncontact Forces
Contact Forces
Gravitational
Nuclear
Pushes
Pulls
Electromagnetic
Tension
Electric
Magnetic
Normal
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Types of Forces
Noncontact Forces
Contact Forces
Gravitational
Nuclear
Pushes
Pulls
Electromagnetic
Tension
Electric
Magnetic
Normal
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Types of Forces
Noncontact Forces
Contact Forces
Gravitational
Nuclear
Pushes
Pulls
Electromagnetic
Tension
Electric
Magnetic
Normal
perpendicular to surface
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Types of Forces
Noncontact Forces
Contact Forces
Gravitational
Nuclear
Pushes
Pulls
Electromagnetic
Tension
Electric
Magnetic
Friction
Normal
perpendicular to surface
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Types of Forces
Noncontact Forces
Contact Forces
Gravitational
Nuclear
Pushes
Pulls
Electromagnetic
Tension
Electric
Magnetic
Friction
Normal
perpendicular to surface
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Aristotle384 - 322 B.C.
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What is the velocity of this room?
400 m/s
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Galileo Galilei (1564-1642)
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Ball on Ramp
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Ball on Ramp
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Ball on Ramp
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Ball on Ramp
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Ball on Ramp

• An object at rest stays at rest and an object in
  motion stays in motion at constant speed in a
  straight line, unless acted upon by a net force.

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Sir Isaac Newton (1642-1727)
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Newtons 1st Law

• No net force - no acceleration
• No acceleration constant velocity
• An object at rest stays at rest and an object in
  motion stays in motion at constant speed in a
  straight line, unless acted upon by a net force.

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Newtons 2nd Law

• Deals with the effect of forces on an object.

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Dry Ice on Slate
Motion of the Block
Velocity
Acceleration
Push or Pull Necessary to Maintain Motion
at rest
uniform motion to the right
0
0
moves to the right and speeds up without changing
direction
moves to the right, slows down and stops without
changing direction
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Dry Ice on Slate
Motion of the Block
Velocity
Acceleration
Push or Pull Necessary to Maintain Motion
0
0
0
at rest
uniform motion to the right
0
0
moves to the right and speeds up without changing
direction
moves to the right, slows down and stops without
changing direction
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Newtons 2nd Law

• Net force causes acceleration (not velocity)
• The net force is the vector sum of all the
  individual forces on an object.

Acceleration is in same direction as the net
force.
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Which one is the net force?
Types of Forces
Noncontact Forces
Contact Forces
Gravitational
Nuclear
Pushes
Pulls
Electromagnetic
Tension
Electric
Magnetic
Friction
Normal
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Pretest 3(the crate in the snow)
?
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Pretest 3(the crate in the snow)