How high can your water rocket really soar? In this experiment, you’ll become a rocket scientist on a mission to unlock the perfect water-to-air ratio that sends your water rocket climbing to its highest possible altitude.

Why Water Levels Matter

Your water rocket is powered by a balance of water and compressed air. Too much water? The rocket becomes heavy. Too little? There’s not enough mass to push it upwards.
Your mission is to discover the sweet spot – the perfect amount of water that creates maximum thrust for an epic launch.

Your Mission – Unlock the Perfect Water to Air Ratio

Design and conduct a full investigation to answer the big question:

What amount of water makes a Water Rokit reach its highest altitude?

To complete your mission:

1. Experiment with different volumes of water in your water rocket.
2. Launch your water rocket multiple times to gather accurate data.
3. Record the height each water level reaches.
4. Present your results visually – a graph is ideal.
5. Identify the champion launch.

Log your results:

• Which water volume gave the best height?
• What was the maximum altitude achieved?

Bonus Challenge: Bottle Size Showdown

Does bottle size change everything? Test 1L, 1.5L, and 2L bottles.

For each bottle:

• What water amount gives the best height?
• What percentage of the bottle’s total capacity is that?
• Are the results consistent across all bottle sizes – or does each have its own secret formula?

Illustrate your findings in a clear and creative way, and be prepared to explain your discoveries.

Need Inspiration?

Watch this experiment exploring water levels in water rocket.