overview

• What is a scalar quantity?

  A quantity with magnitude but no direction
• What is a vector quantity?

  A quantity with both magnitude and direction
• What are the two groups of forces?

  Contact forces and non-contact forces
• What is weight?

  The force acting on an object due to gravity
• What does it mean that weight and mass are directly proportional?

  If mass doubles, weight also doubles
• What is the center of mass?

  The point where weight appears to act
• What is a free body diagram?

  A diagram showing forces acting on an object
• What does resultant force mean?

  The overall force acting on an object
• How do you find the resultant force when forces act in the same direction?

  Add the forces together
• How do you find the resultant force when forces act in opposite directions?

  Subtract the smaller force from the larger force
• What do you do when forces are at right angles to each other?

  Use a scale drawing to find the resultant force
• How do you find the horizontal and vertical components of a diagonal force?

  Use a scale drawing to measure distances
• What is work done on an object?

  When a force moves an object a distance
• What happens during deformation of an object?

  The object changes shape due to applied forces
• 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 happens to work done in elastic deformation?

  Converted into elastic potential energy
• What happens to work done in inelastic deformation?

  Wasted as heat to surroundings
• How is elastic potential energy calculated?

  Using the equation for elastic potential energy
• What does Hooke's Law state?

  Force is directly proportional to extension
• What happens when Hooke's Law is no longer obeyed?

  The graph starts to curve at the limit of proportionality
• How is the spring constant determined?

  By finding the gradient of the straight line
• What is distance?

  How far an object moves
• What is displacement?

  The overall distance and direction from start
• What is speed?

  How fast an object moves
• What is velocity?

  The speed of an object in a given direction
• What does a distance-time graph show?

  Motion of an object over time
• What does a flat horizontal line on a distance-time graph indicate?

  The object is not moving
• What does a steep line on a distance-time graph indicate?

  The object is moving faster
• What does a curved line on a distance-time graph indicate?

  The object is accelerating or decelerating
• How do you find speed from a distance-time graph?

  Find the gradient of the line
• What does a velocity-time graph show?

  Change in velocity over time
• What does a flat horizontal line on a velocity-time graph indicate?

  The object is traveling at constant speed
• What does a steep line on a velocity-time graph indicate?

  Greater acceleration of the object
• What does a curved line on a velocity-time graph indicate?

  Changing acceleration or deceleration
• How can you find the distance traveled from a velocity-time graph?

  Calculate the area under the graph
• What is terminal velocity?

  The constant speed reached during free fall
• What happens to forces when a person falls?

  Weight and drag act on the person
• What occurs when drag equals weight during a fall?

  The speed becomes constant, no acceleration
• What does Newton's first law state?

  Balanced forces mean constant speed or stationary