You will need:
- An empty soap dish
- Two long needles
- Four round plastic buttons
- A broomstick bristle (about 20cm long)
1. Make holes in the soap dish: one each on both ends of the long sides, as in the pic.
2. Heat the tip of a needle and poke it into the centre of a button. Repeat the process with the other needle and another button.
3. Fix both the button-needle contraptions into the holes of the soap dish. Now heat the eyes of the needles and fix a button on each.
4. Tie thread on one end of the broomstick bristle. Fix the other end of the bristle to the back of the soap dish.
5. Tie the other end of the thread to the needle of the front wheels.
6. Put the car on the ground and pull it back. The thread winds around the needle and the broomstick bristle bends.
7. Release the car. The potential energy stored in the bristle gets converted to kinetic energy and the car moves forward.
by Arvind Gupta (www.arvindguptatoys.com)
artwork by Somesh Kumar