Try this alternative to the basic dragster design:
– Use cotton buds and 16 mm wooden beads for wheels (3.5p each on eBay), instead of the more expensive MUTR axles and wheels.
– Add a cardboard base-plate (15 cm x 4.5 cm) allowing the straws to be aligned better, so straighter runs can be achieved.
– Sellotape a cardboard seat on top to take:
1. 2 x 10 g slotted masses, approximately equivalent to the total mass of the modified dragster. Measure the effect of mass on launch speed (measured using a light-gate) at constant initial air pressure.
2. a Physics-bug passenger or Lego-man, which ‘flies off’ (continues moving forward) if he’s not wearing an elastic band seat-belt when the dragster crashes. Investigate how far does he fly forward at different speeds?
(See also the SEP booklet ‘Rockets and Projectiles’ available from http://www.sep.org.uk to SEP associates for a different design and more ideas.)