Overview: Making a hole or holes in a bottle top can create a sprinkler system. However it isn’t easy to control the speed of the flow of the water as the pressure inside the bottle varies depending on how full the bottle is. What can you do to create a system that only needs refilling at appropriate time gaps?
Task: You are to create a watering system from a plastic bottle that releases water at a controlled rate. so it only needs filling up at certain time intervals that you choose: Every 24 hours every week etc
Equipment Provided: Plastic bottles (some with sports drinking caps if available) Knife / scissors. Optional Mounted needle and matches (for melting small holes )
Health and Safety: You must carry out your own risk assessment (Rubbish Science accept no liability) Note: Take care when cutting. Take great care if burning holes – Chance of burning yourself and be aware that burning plastic gives off fumes so do in a well ventilated place
Things you might need to know / Questions you might ask:
- Why doesn’t water come out of a bottle withe a hole in the lid when turned upside down?
- How can I make water come out?
- What happens if I make a bigger hole in the lid?
- Do 2 holes drip twice as fast as 1?
- How might I control the flow of water?
Prototyping: Try to answer the questions above using small scale experiments
Modifications:How might you modify your designs based on what your preliminary results look like? What have others done and what can you learn from them?
Prediction: What do you think will happen and why?
Do it: How are you going to see if your garden is successful?
What happened?: Was your bottle garden effective?
Tell Someone: Explain what you did and why you felt your plant growing was effective. Listen to others do they have any good ideas?
What did you learn? What do you know now that you didn’t know before you started this investigation?
Extension/Modify/Do it again: How could you extend this to produce a commercial plant growing business
Possible Model – How can you optimise the design?