1. A plastic bottle is used to make a boat. The cap of the plastic bottle is screwed on tightly.

2. A line is cut at the middle of the bottle and a lump of

plasticine is put into the bottle

3. Using adhesive tape, two sticks are taped to the sides of the bottle

4. Two rectangles are cut from a cardboard.Note: They are not as wide as the plastic bottle.

5. A slit is made halfway down each rectangle.

6. The two rectangles are slid together to form a cross-shaped paddle.

7. An elastic band is taped to the paddle and the ends of the elastic band are fixed on the sticks.Note: The paddle should not touch the bottle.

8. The elastic band is wound up and the boat is placed in a basin of water.

9. Observation is made as the paddle spins to make the boat more forward.

10. The time taken for the boat to move a fixed distance is recorded.

11. Another boat is made, but this time the paddle is taped to the top of the bottle.

12. The movement and the speed for both boats are compared.