b) Graphs

b) graphical representations of displacement, speed, velocity, and acceleration

c) displacement-time graphs; velocity is gradient

d) velocity-time graphs; acceleration is gradient; displacement is area under graph

displacement-time graph

• y-axis = displacement (m)

  • x-axis = time (s)

• gradient = velocity (ms^-1)

  • constant gradient = constant speed/velocity

  • changing gradient = acceleration

  • zero gradient = zero speed/velocity

velocity-time graph

• y-axis = velocity (ms^-1)

• x-axis = time (s)

• gradient = acceleration (ms^-2)

  • constant gradient = constant acceleration

  • changing gradient = changing acceleration

  • zero gradient = zero acceleration/constant velocity

area underneath a velocity-time graph = displacement

• when the acceleration is constant

  • calculate the area of the component shapes

  • add up the areas

• when the acceleration is changing

  • count the number of squares entirely or almost entirely below the graph

  • multiply by the displacement of each square