We always called these "Water rockets", "bottle rockets" were small firecrackers with a booster charge and a long stick to stabilize them, launched from a bottle or similar item.
Water rockets were clear rocket-shaped tubes that came with a pump, you filled them with water and then pumped air inside to pressurize it. When the hold-down device was released the pressure forced the water out, creating thrust.
Suzuran_Majere said: We always called these "Water rockets", "bottle rockets" were small firecrackers with a booster charge and a long stick to stabilize them, launched from a bottle or similar item.
Water rockets were clear rocket-shaped tubes that came with a pump, you filled them with water and then pumped air inside to pressurize it. When the hold-down device was released the pressure forced the water out, creating thrust.
True. But I was taught how to make them in school using old 2 liter bottles. Hence the reason I (as well as many others I presume) sometimes will call them bottle rockets.