What pushes a rocket forward? The same force can push a small boat across a bathtub. You build a boat from balsa wood and mount a sealed metal tube filled with hot water above two candles. When the candles heat the water, it turns to steam. The steam escapes through a small hole in the cork. That escaping gas pushes the boat forward. This is the same action-reaction principle that launches real rockets.
Hypothesis
The hypothesis is that the steam-powered boat will move through the water.
When candles heat water inside a sealed metal tube, the water turns to steam. That gas needs somewhere to go — it escapes through a small hole in the cork. As the steam pushes out, it drives the boat forward across the water. The same action-reaction principle that launches real rockets is at work here.
Candles turn chemical energy into heat. That heat warms water sealed inside a metal tube mounted above the candles until it turns to steam. When the steam escapes through a small hole in the cork, it pushes the boat forward — the same action-reaction principle that launches real rockets.
What pushes a rocket forward? The same force can push a small boat across a bathtub. You build a boat from balsa wood and mount a sealed metal tube filled with hot water above two candles. When the candles heat the water, it turns to steam. That steam escapes through a small hole in the cork, pushing backward — and that backward push creates an equal forward force that moves the boat. It is the same action-reaction principle that launches real rockets.
Method & Materials
You will build a boat out of balsa wood and attach two food warmer candles to it. You will also attach a metal tube with a cork in it to the boat.
You will need a metal tube, two pieces of strong wire, a cork, two food warmer candles, balsa wood, masking tape, a hammer, and three nails.
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The experiment showed that the steam-powered boat was able to move through the water. This demonstrates the power of steam and how it can be used to propel objects.
Why do this project?
This science project is interesting and unique because it combines the principles of energy and propulsion to create a working boat.
Also Consider
Experiment variations to consider include using different types of fuel for the candles and using different shapes for the boat.
Full project details
Additional information and source material for this project are available below.
