Depth-Time Graphs – Demonstration This resource provides animated demonstrations of the mathematical method. Check animations and delete slides not needed for your class.

Depth-Time Graphs Jack needs to fill his two fish tanks. The large fish tank is the same height and width, but twice the length. Which tank will fill first? How much quicker? The two taps give the same rate of water.

Jack needs to fill his two fish tanks. Depth-Time Graphs Jack needs to fill his two fish tanks. The large fish tank is the same height and width, but twice the length. Which tank will fill first? How much quicker? Small Big MAX Depth Time

Jack needs to fill his two fish tanks. Depth-Time Graphs Jack needs to fill his two fish tanks. The large fish tank is the same height and width, but twice the length. Which tank will fill first? How much quicker? The volume increases at the same rate, but the depth increases at a faster rate in the small tank. The speed of increase is represented by the gradient. Small Big MAX Depth Time

Amanda also has two tanks. Depth-Time Graphs Amanda also has two tanks. They are the same height, but the large tank is twice the volume. On the same grid, sketch the depth-time graph for each container. MAX Small Big Depth Time

Faster rate of depth increase Depth-Time Graphs What does the depth-time graph look like if the tanks were on top of each other? The total container is double the height MAX Faster rate of depth increase Depth Slower rate of depth increase Time

During each section the rate is constant. Depth-Time Graphs This tank is made from three sections of equal height. Sketch the depth-time graph for the container. Fastest Depth Medium Slowest Time During each section the rate is constant.

Depth increases at fastest rate. Depth-Time Graphs This tank fills faster at the top than at the bottom. Sketch the depth-time graph for this container. Depth increases at fastest rate. It is not a constant rate at any time. Depth The gradient is always increasing. Starts slow Time

Increasing at a steady rate Depth-Time Graphs This tank is made from a sphere and a cylinder. Sketch the depth-time graph for the container. Increasing at a steady rate Rate of increase speeds up Depth Starts fast, then rate of increase slows Time

Match each container with a depth-time graph. 1 A B C 2 G D E F 3 4 5 6 7

Answers 1 E A B C 2 G D E B F 3 4 5 6 7 G F D A C

Sketch a depth-time graph for each container. B C G D E F

Answers A A B C G B D E F C D E F G

tom@goteachmaths.co.uk Questions? Comments? Suggestions? …or have you found a mistake!? Any feedback would be appreciated . Please feel free to email: tom@goteachmaths.co.uk