Physics 10

• Significant Digits


  Multiplication & Division Rules
• Multiplication & Division Rules

  1. Carry out the full operation

  2. Do not round any part until the final answer

  3. Round your final answer to the least # of significant digits the calculation
• Addition and Subtraction Rules

  • Carry out the full operation
  • Do not round until the final answer
  • Round your final answer to the least # of decimal places in the calculation
• If there are multiple operations, use the multiplication and division rules
• Scientific Notation


  • Used to concisely represent really large or really small numbers
  • Allows us to represent numbers to the proper amount of significant digits
  • _.___ x 10__
  • There is always one # to the left of the decimal
• Expanding Scientific Notation


  1. 4.5 x 103

  2. 2.73 x 10-4
• Uniform Motion


  Motion in a straight line at a constant speed
• Non-Uniform Motion


  Motion with a change in speed, direction, or both
• Instantaneous Speed


  Speed which something is moving at a particular instant in time
• Average Speed


  v = speed (m/s or km/h)

  Δ = change

  d = distance (m or km)

  t = time (s or h)
• Distance-time graph (d-t graph)

  For uniform motion, line of best fit is a straight line with a positive slope
• The graph shows faster or slower motion than the average speed
• Slope


  The measure of the steepness of a line
• Calculating slope


  • Never use data points
  • Look for 2 points on line of best fit that are in an intersection or halfway between grid lines
• Calculating slope formula


  1. Y2 - Y1

  2. X2 - X1
• Calculating slope


  • (3.5, 25)
  • (1.5, 10)
  • Slope = 25m - 10m
  • 3.5 s - 1.5 s
  • = 7.5 m/s
• Scalar


  A quantity consisting of magnitude only
• Vector


  A quantity of magnitude and direction
• Velocity


  Velocity and Displacement are VECTORS. They require a convention or a direction with magnitude.

  
• Velocity


  v = velocity

  
• Displacement


  Δ = change, d = displacement, t = time

  
• Displacement


  The distance from your starting position to the ending position. It is a vector quantity so it requires a direction.

  
• Sign Conventions


  • North (positive)
  • East (positive)
  • Up (positive)
  • Forward (positive)
  • South (negative)
  • West (negative)
  • Down (negative)
  • Backwards (negative)
• Acceleration


  Change in velocity over a specific time interval
• Acceleration is not uniform motion
• Acceleration


  • It is a vector
• Calculating acceleration


  Acceleration (m/s2) = (final velocity (m/s) - initial velocity (m/s)) / (final time (s) - initial time (s))

  
• Positive acceleration


  Both the change in magnitude and direction of the velocity are positive

  
• Negative acceleration


  Both the change in magnitude and direction of the velocity are negative
• Acceleration with change in magnitude negative and direction positive

  The change in magnitude of the velocity is negative and the direction of the velocity is positive

  
• Uniform acceleration


  • Acceleration described by a sloping, straight line on a velocity-time graph

  
• Force


  A push or pull on an object, measured in Newtons (N)
• Objects at Rest


  • Do not move since all forces acting on it are balanced
  • Forces equal in magnitude, opposite directions
• Objects in Motion


  • Move when a force moving in one direction is greater than a force moving in an opposite direction
  • Move in the direction of the unbalanced force
  • Once in motion, tend to stay in uniform motion
  • Unbalanced forces such as friction will either speed up or slow down the object
• Work


  • When a force moves an object through a distance
  • Requires: 1) there must be a force (F), 2) the object MUST move position (d), 3) object must move in same direction as the applied force

  
• Joule (J)


  Unit of work, 1 J = 1 N m
• Energy


  The ability to do work, measured in Joules (J)
• If we assume there is NO loss of energy during a transfer

  The change in energy equals work done
• Scalar


  A quantity consisting of magnitude only
• Vector


  A quantity of magnitude and direction