Other Design Challenges
Design and build a wind powered machine that will pull a wooden block across a horizontal floor in the shortest time.
The machine may be constructed out of any material. The maximum limits are as follows: NO mass limit, height of 30cm, length of 30cm, and width of 30cm (all measured with the machine lying on a flat
table). It must use a 3/16inch wooden dowel rod as a vertical axle around which a string or cord will wind up the block.
A 4.0M string or cord is to be attached to the wooden dowel. The string or cord should have a loop at the end that will be attached to the block.
The block will be a 2”X4” that is 4 inches long with a hook in the end of it. A 24” window fan will be used to power the machine. No other source of power may be used.
With the window fan placed on the floor, the machine’s front edge will be placed 50cm in front of the fan. The block will start from a location that is 4.0m from the fan.
The fan will be turned on and the contestant will be instructed to allow the wind machine to start winding the block. The timing will begin when the block crosses that start line and end when it crosses the finish line.
The starting line will be located 3.5m for the fan and the finish line will be placed 1.5m from the fan. Each entry will have two runs. The slower run will be used to break any ties.
1) How did the shape of the fan blades affect the speed?
2) Did more fan blades improve the design?
3) How would you revise your design for a future test?