physics forces x

• What is the difference between a vector and a scalar quantity?

  A vector has direction; a scalar does not
• How are vectors used to describe forces?

  Vectors represent forces with magnitude and direction
• How do you calculate the resultant of two forces acting in a straight line?

  Add or subtract their magnitudes
• What is the difference between mass and weight?

  Mass is matter; weight is gravitational force
• What symbol is used to indicate proportionality?

  The symbol ∝
• How are vector diagrams used in physics?

  To show resolution and addition of forces
• What does a scalar quantity have?

  Magnitude only
• What does a vector quantity have?

  Magnitude and direction
• How can arrows represent vector quantities?

  Length shows magnitude; direction shows action
• What type of quantities are forces?

  Vector quantities
• What are contact forces?

  Forces where objects are touching
• What are non-contact forces?

  Forces where objects are not touching
• What is gravity?

  A force of attraction between all masses
• What does weight depend on?

  Gravitational field strength and mass
• What is the gravitational field strength on Earth?

  9.8 N/kg
• How do you calculate weight?

  Weight = mass × gravitational field strength
• What is the centre of mass?

  The point where weight acts on an object
• What is a resultant force?

  The single force equivalent to multiple forces
• What is a free body diagram?

  A diagram showing all forces on an object
• How are scale vector diagrams used?

  To illustrate overall effects of multiple forces
• How do you add vectors in a scale vector diagram?

  Add vectors head to tail
• What happens when a force acts diagonally?

  It can be resolved into two perpendicular forces
• What is the equation for work done?

  Work done = force × distance
• What is the relationship between work done and energy transfer?

  Work done transfers energy within a system
• What is elastic deformation?

  When an object returns to its original shape
• What is inelastic deformation?

  When an object does not return to its original shape
• What is the limit of proportionality?

  The point where force and extension relationship changes
• What does the spring constant indicate?

  How easy it is to stretch or compress a spring
• What is the equation for force in a spring?

  Force = spring constant × extension
• What is the relationship between work done and energy stored in a spring?

  They are equal if not inelastically deformed
• What is a moment of a force?

  The turning effect caused by a force
• How do you calculate the moment of a force?

  Moment = force × distance from pivot
• What happens when an object is balanced at a pivot?

  Total clockwise moment equals total anticlockwise moment
• How do levers and gears work?

  They transmit and magnify forces
• What is the equation for pressure?

  Pressure = force / area
• How does atmospheric pressure vary with height?

  It decreases as altitude increases
• What effect does fluid density have on pressure?

  Higher density increases pressure
• How do you calculate pressure difference at different depths?

  Use pressure = height × density × gravity
• What is upthrust?

  The upward force exerted by a fluid
• What happens when an object is less dense than the liquid?

  It floats and displaces liquid equal to its weight