P5

• What are scalar quantities?

  Quantities with only magnitude, no direction
• What are vector quantities?

  Quantities with both magnitude and direction
• What does the direction of an arrow in a vector represent?

  The direction of the quantity
• What does the length of an arrow in a vector indicate?

  The magnitude of the quantity
• What is a force?

  A push or pull on an object
• What are contact forces?

  Forces that require objects to touch
• Name a type of contact force.

  Friction
• What are non-contact forces?

  Forces that do not require contact
• What is weight?

  Force acting on an object due to gravity
• How is weight measured?

  With a calibrated spring-balance
• What is the formula for weight?

  W = mg
• What does the centre of mass represent?

  Point where an object's weight appears to act
• How does an object's weight depend on its location?

  Depends on gravitational field strength
• How does an object's mass behave in the universe?

  Has the same value anywhere in the universe
• What is a free body diagram?

  • Diagram showing all forces on an object
  • Helps visualize forces acting on an isolated object
• What is a resultant force?

  Single force replacing all acting forces
• How do you calculate resultant force?

  Add forces in the same direction, subtract others
• What happens when work is done on an object?

  Energy is transferred to the object
• What is equilibrium?

  When forces acting on an object are balanced
• How can you create a closed loop in force diagrams?

  Draw forces tip-to-tail in scale drawing
• What is the work done formula?

  W = Fs
• What is elastic deformation?

  Object returns to original shape after forces removed
• What is inelastic deformation?

  Object does not return to original shape
• What is the force-extension relationship for elastic objects?

  Force is directly proportional to extension
• What happens when the force exceeds the limit of proportionality?

  Extension is no longer proportional to force
• What is a moment?

  The turning effect of a force
• What is the formula for calculating moments?

  M = Fd
• What does it mean if total clockwise moment equals total anticlockwise moment?

  Object is balanced
• What are gears used for?

  To transmit rotational effect of a force
• How do levers help in doing work?

  They make it easier to lift a load
• What is fluid pressure?

  Force exerted normal to a surface by fluid
• What is upthrust?

  Resultant force acting upwards on submerged object
• What happens when upthrust equals weight?

  Object floats
• What is atmospheric pressure?

  Pressure created by air molecules colliding
• How does atmospheric pressure change with height?

  It decreases as height increases
• What is distance?

  How far an object has moved
• What is displacement?

  Distance and direction from starting to finishing point
• What is speed?

  How fast an object is moving
• What is velocity?

  Speed in a certain direction
• What is acceleration?

  Change in velocity over time