KEY WORDS

• What is accuracy in measurements?

  How close a measurement is to its true value
• What influences accuracy in measurements?

  Systematic and random errors
• What are base units?

  The set of seven basic measures in SI
• What is the purpose of estimation in physics?

  To make a reasonable approximation of a value
• What does precision refer to in measurements?

  Closeness of repeated measurements to each other
• What influences precision in measurements?

  Random errors of those measurements
• What is random error?

  Unpredictable variation in a measurement
• How can random errors be reduced?

  By taking many repeated measurements
• What does repeatability mean in an experiment?

  Same person gets the same result multiple times
• What is required for an experiment to be repeatable?

  Same person with the same equipment
• What does reproducibility mean in an experiment?

  Different people get similar results
• What is resolution in measurements?

  The smallest interval a measuring device can measure
• What is systematic error?

  A consistent shift in readings from the true value
• What causes systematic errors?

  Equipment or method being used
• What is uncertainty in measurements?

  The range of values that could contain the true value
• What does uncertainty depend on?

  The confidence an experimenter has in their result
• What is lift in physics?

  A force acting upwards against gravity
• How is moment defined in physics?

  Product of force and perpendicular distance to pivot
• What is momentum?

  Product of mass and velocity
• What does Newton's First Law state?

  An object remains at constant velocity unless acted on
• What does Newton's Second Law describe?

  Acceleration is proportional to force and inversely to mass
• What is Newton's Third Law?

  Every action has an equal and opposite reaction
• How is power defined in physics?

  Work done divided by time taken
• What is a resultant force?

  The sum of all forces on an object
• What is a scalar quantity?

  A quantity with only magnitude
• What is terminal velocity?

  The maximum velocity an object can achieve
• What defines a vector quantity?

  A quantity with both magnitude and direction
• How is weight defined in physics?

  Force of gravity on an object, mass times gravity