Sophia built a motor boat out of plastic foam, a battery, motor, switch, and wires. She cut the foam into the shape of a boat and cut out a section to hold the battery. She connected the motor, switch, battery and inserted a pen core attached to a metal screw propeller. When the switch is pressed, the motor runs the propeller which propels the boat across the water's surface using Newton's third law of motion.

1. Motor boat by Sophia

2. Materials A battery (9V) A motor A switch wires

3. plastic foam a pen core foam tape a scissors a knife

4. process cut the plastic foam to make the shape of boat

5. Then cut out some foam in the middle of the board to set the battery .

6. Insert the pen core into one of the end of the motor. Link the motor, switch, wires, and battery as the image shows.

7. Use foam tape to stick the junctions. Put them into the boat. Bend a piece of metal as a screw propeller. Insert it into the pen core. Finally, a motor boat comes into the world~ when you press the switch, the boat can run on the surface of water~

8. Bend a piece of metal as a screw propeller. Insert it into the pen core. Finally, a motor boat comes into the world~ when you press the switch, the boat can run on the surface of water~

9. How does it work The motor is the equipment which converts electric energy into mechanical energy. Because of the mechanical energy the motor exerts, The propeller turns and forces water out the back. Since Newton's third law: Action and reaction are equal and opposite, the force exerted by the propeller backwards on the water equals the force exerted by the water forward on the boat. It is why the boat moves forward.