Combining physics with creativity, more than 1,000 secondary school students showed off their talents in a competition aimed at raising teenagers' interest in science. About 300 teams - each comprising two to four students - from 80 secondary schools took part in the Hong Kong Inter-school Straw Waterwheel Object Lifting Competition on April 17. It was organised by the Students' Union Physics and Materials Science Society of the City University of Hong Kong. The contest was divided into two categories - for Form One to Form Three students, and Form Four or above. It was the eighth year that the society had organised such an activity for secondary school students in Hong Kong. The organisers hope to raise students' interest in physics through real-life applications that highlight the dynamic nature of scientific concepts. To make the competition more exciting and challenging this year, participants were asked to apply a key physics concept - the potential energy of water - in creating their models. In 90 minutes, each team had to use 150 straws and a roll of string to design a water-driven mechanical device to lift a nut. The height of the nut was the main judging criterion. Raising a 40-gram nut 271 centimetres from the ground, students from Tang King Po School beat more than 200 teams to win the senior category. The first runner-up prize went to another team from the same school, who raised the nut 261.7 centimetres. A team from Shap Pat Heung Rural Committee Kung Yik She Secondary School was the second runner-up. In the junior category, three teams from Shap Pat Heung Rural Committee Kung Yik She Secondary School scooped top prizes. The junior champion raised a 20-gram nut 281 centimetres from the ground. The winners were awarded book coupons worth $500 to $1,500.