How fast does a balloon rocket go?

The speed of a balloon rocket can vary significantly depending on several factors, including the size of the balloon, the amount of air or gas it contains, and the design of the rocket. Generally, a balloon rocket can achieve speeds ranging from a few centimeters per second to several meters per second. In experimental setups, some balloon rockets have reached speeds of up to 30 meters per second (about 67 miles per hour) under optimal conditions. However, most simple balloon rocket experiments yield much lower speeds.