Fundamentals of physics

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Fundamentals of physics
Mechanics
Unit 5 Motion and Forces 5.2 Vectors and
Scalars ...
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Fundamentals of physics - Mechanics

• Vectors and Scalars
• --------------------------------------------------
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• A vector quantity is one that has magnitude
  (size) and direction.
• Velocity, force, acceleration, and momentum are
  vector quantities.
• A scalar quantity only has magnitude alone.
• Speed, time, temperature, and energy are some
  examples of scalar quantities.

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Fundamentals of physics - Mechanics

• Vectors and Scalars
• --------------------------------------------------
  --------------------------------------

• Vector quantities may be represented by arrows.
• The magnitude of the vector quantity is
  represented by the length of the direction by
  the arrowhead.
• An arrow drawn to scale and pointing in the
  appropriate direction represents a vector.

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Fundamentals of physics - Mechanics

• Adding Vectors
• --------------------------------------------------
  --------------------------------------

• Consider the forces F1 and F2 acting on a body
  in the directions shown in the diagram.
• The resultant Fr is the diagonal of the
  parallelogram.

A displacement of 12m North followed by 5m East.
Resultant displacement is 13m at a bearing of
22.6o.
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Fundamentals of physics - Mechanics

• Vectors and Scalars
• --------------------------------------------------
  --------------------------------------

• The weight of a wheel rolling down an inclined
  plane can be considered as the resultant of two
  forces S (parallel to the plane) and D
  perpendicular to the plane.

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Fundamentals of physics - Mechanics

• Vectors and Scalars
• --------------------------------------------------
  --------------------------------------

• Would a wheelbarrow sink deeper when it is
  pushed or pulled over soft soil?
• Answer Consider the effort F applied on the
  wheel by the person. If F points downward
  (pushing) then the component Fd adds to the
  weight of the wheelbarrow and when the effort is
  applied upward it subtracts from the weight. Thus
  in pushing the net force on the wheels is greater.

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End of Unit 5 Motion and Forces5.2 Vectors and
Scalars...