can you give some complicated project ideas for a science fair.?

Question

i am 7th grade.its alright that does not matter.i want some complicated ideas

Answer 1

Build a 3-D model of the Martian surface (from actual photos taken by the rovers) and then build a rover (a plastic kit might be available)

Answer 2

1. One of the boys in my neighbourhood developed a 250 cc motor car and put scooter tyres, a hose pipe and a couple of garden chairs. He used a kerosene genset for the motor. Speed limit 20 kmph max. and the speed used to get adjusted by the throttle of the Honda genset. The hand clutch and the brake cables and the lever were those from a two-wheeler Piaggio (Vespa) running thru the back of the driver-chair and on the small brakes fixed on the back wheels. No front brake. It used to start with a jerk and gain small momemtum. No steering, it was a mobike handle welded to the front wheels for manouvring. It was a marvelous idea and won him the first prize in the National Science Fair, New Delhi some 20 years back. The idea was indeed innovative but a bit expensive by any standards those days.
2. Another option : You cud also try building a small bicycle which floats on water by using big pvc rounds (or tubes with dia say 20")(or discs cut our to act as the two wheels). Width of the wheels to be abt 18". No power is required, only manual pedaling. So you cud perhaps think and try working out by putting a pedal, a shaft, a small chain and watch-like discs as in a conventional bicycle for the movement forward.The discs (wheels) have to be broad enough so as the bicycle does not throw the driver in water. As it is PVC, it will float (or may be u cud also try putting inflated bike tubes inside the wheels if you feel the weight of the other material may partly submerge the bicycle). Pedals may remain somewhat or half below the water level, never mind, but make sure the dia is big enough so as to consume less of energy while pedalling and pushing the apparatus forward. It will be an good idea if you have li'l pond nearby for the demo. Good luck!

Answer 3

How about an electric lock for your bedroom door. Say using a gate latch, solenoid and batteries.
The key could be a key switch or a set of switches on the outside of the door that all have to be in the right position for the current to pass.

Answer 4

Construct a hydrogen fuel cell. It is sure to win points with any judge that had to go to the gas station on the way to the fair.

Answer 5

Use a simplified version of isotope extraction to seperate the salt from the water in salt water.

Answer 6

Land a man on Mars and bring him safely back before NASA or Russia get there. I foresee very high marks, and possibly a distinction coming up here ....