Students observe, identify and describe the relationship between the depth of liquid in a vessel and the shape of the vessel when it is being filled at a uniform rate of flow. Graphs (depth of liquid in the vessels against time) are used to represent the relationships between depth and vessel shape.

Teacher notes

  • Students predict either the shape of the graph that will match the depth of liquid flowing into a glass, or predict the shape of the glass which matches a graph of filling rate.
  • Students observe how the shape and slope of a graph can be linked to physical attributes of objects.
  • Feedback about the relationship between the graphs and glasses is provided after each selection.

Learning objects

Filling glasses picture.

Filling glasses: graphing and comparing
Students compare the graphs of filling rates produced from filling two glasses with different shapes.

Filling glasses picture.

Filling glasses: find the right glass
The student predicts and selects appropriate glasses to match the randomly presented graphs.

Filling glasses picture.

Filling glasses: find the right graph
This is a matching exercise where the student is required to choose an appropriate graph to match a randomly selected glass. The student needs to match both elements to match to fill the glass successfully.

Filling glasses picture.

Filling glasses: create the right glass
Students create their own glass from preset components (top and bottom parts) to match to a randomly presented graph.

Filling glasses picture.

Filling glasses: create the right graph
Students create their own graph from preset components to match randomly presented glasses formed from a set of top and a bottom parts.