How does the bow of a ship influence water resistance?
The materials required for this science fair project are:
- 1 water tank measuring: length 1.0m x width 0.8m x height 0.8m (inner tank)
- 1 water tank measuring: length 1.5m x width 1.0m x height 0.3m (outer tank)
- 3 water pumps (which can be purchased from an aquarium shop)
- 1 wooden boat - cuboid shape (approximately 250mm long x 80mm width)
- 1 wooden boat - half cylindrical in shape (approximately 250mm long x 80mm width)
- 1 wooden boat – curved bottom with a V-shape bow (approximately 250mm long x 80mm width)
- 1 Newton spring balance
- 300 grams weight
- 1 ruler
- 2 tanks of tap water
1. The independent variable for this science fair project is the shape of the boat’s bow. The dependent variable is the amount of drag experienced by the boat in the water. The amount of drag is measured using the Newton spring balance. The constants (control variables) are the flow rate of the water, the weight placed in the boats and the size of the wooden boats.
2. The 3 boats are made of wood, as shown according to figure 1 above. The approximate dimensions of the boats are 250mm in length and 80mm in width.
3. The two water tanks are arranged as per figure 2 above. A 20mm cut is made on the shorter side of the inner tank as shown. This will determine the direction of the water flow. Fill both tanks with water.
4. Place three water pumps outside the water tank as shown. The water will be pumped into the inner tank, on the side that has not been cut. When the pumps are turned on, the water will flow from one end of the inner tank to the opposite end.
5. Fix the he cuboid wooden boat and Newton spring balance into the inner tank as shown. Place the 300 grams weight inside the wooden boat to stabilize it. Turn on the 3 pumps. Record The measurements on the Newton spring balance in the table provided below.
6. Repeat step 5 using the half cylindrical shaped and the V-shaped boats. The measurements of the Newton spring are recorded in the table provided below.