# Starter A dripping tap This tap drips water

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Starter: A dripping tap This tap drips water at a constant rate.

It drips water into a container. What will the graph look like?

It drips water into a container. What will the graph look like?

It drips water into a container. What will the graph look like?

It drips water into a container. What will the graph look like?

It drips water into a container. What will the graph look like?

It drips water into a container. What will the graph look like?

It drips water into a container. What will the graph look like?

It drips water into a container. What will the graph look like? The graph is a straight line, starting from the origin (0, 0)

What will the graph look like for each of these containers?

What will the graph look like for each of these containers?

Example Draw a conversion graph to convert between gallons and litres. Use the fact that 1 gallon is approximately 4. 55 litres. Use your graph to convert 15 gallons to litres, and 45 litres to gallons.

Example Draw a conversion graph to convert between gallons and litres. Use the fact that 1 gallon is approximately 4. 55 litres. Use your graph to convert 15 gallons to litres, and 45 litres to gallons. Solution: first find some co-ordinates. You know 0 gallons = 0 litres. You are told 1 gallon = 4. 55 litres, so 10 gallons = 45. 5 litres. You can work out 20 gallons = 91 litres

Plot the 3 points, and then join them with a straight line – use a ruler to do this.

To convert 15 gallons to litres: Read up from 15 gallons to the line, then across to the vertical scale. Draw a line on your graph to show this is what you are doing (it is your working out). 15 gallons is the same as 68 litres.

To convert 55 litres to gallons: Read across from 55 litres to the line, then down to the horizontal scale. Draw a line on your graph to show this is what you are doing (it is your working out). 55 litres is 12 gallons.