as level physics mechanics and materials

• What is a scalar quantity?

  A force with a magnitude
• What is a vector quantity?


  Forces with magnitude and direction
• What conditions need to be met for an object to be in equilibrium?


  Resultant forces acting on the object must be equal to zero
• What is the definition of a moment?


  Force multiplied by the perpendicular distance from the line of action of the force to the point
• What is a couple?

  A pair of coplanar forces where the two forces are equal in magnitude and opposite in direction
• State the principle of moments


  For an object in equilibrium, the sum of anti-clockwise moments about a pivot is equal to the sum of clockwise moments
• When an object is described as uniform, where does the centre of mass act?

  The centre of the object
• What is instantaneous velocity?


  Velocity of an object at a specific point in time
• How do you find instantaneous velocity?


  Using a tangent to calculate the gradient of a displacement time graph
• What does the area under the graph in an acceleration time graph show?

  Change in velocity
• What does the gradient of a velocity time graph show?

  Acceleration
• What does the area under a velocity time graph show?

  Displacement
• How is projectile motion calculated?


  Vertical and Horizontal components are independent from each other, SUVAT can be used for vertical components, S=D/T can be used for horizontal components