Physics – Pd. B – Mr. Levesque
May 30, 2013
Electric Boat Project Report
For the initial design of the boat, we knew that we desired a speedboat rather than a fan boat because of the benefits of less air resistance and to keep the boat closer to the water level. We also wanted the boat to be constructed out of a wooden frame instead of other materials like Styrofoam or duct tape. Originally I had proposed the idea of carving a boat shape out of a solid block of wood, but decided to follow the shape of a fan boat, because of its light weight and smooth shape, and because it would be a lot less labor-intensive than carving out the boat from the wood block. Finding and purchasing most of the materials was not difficult, as Radio Shack had all of the required parts for the circuit, including the large motor and the switch. The only difficult part to find was the propeller, but a trip to Mr. Levesque’s box of old motors and propellers quickly rectified the situation, and we soon had a large, powerful propeller. The most difficult part of assembling the boat was making sure that the motor didn’t vibrate too much in the base of the boat, and also making sure that it was mostly in the water when it was spinning so that we had maximum power and the boat would have a high efficiency in the water.
The total mass of the boat, including the batteries and the rock (see analysis below) was 199g.
The average time it took to race the 5 meter race was 10.3 seconds.
The average speed of the boat, V = D/T, is 0.485 m/s.
The average acceleration of the boat, D = .5(A)(T2), or A = 5/(.5(10.32)), is .0943 m/s2.
The acceleration of the boat is constant during the race because the acceleration at the beginning is averaged over the course of the whole race after the boat reaches its maximum speed.
If the force forward on the boat is less than the resistance forces acting on the boat, then the boat will accelerate forward. The boat’s acceleration also...