The basic idea is to use several chambers on the water rocket, one which provides an initial short “boost” phase of high acceleration, followed by a longer “sustain” level of acceleration ...

To calculate acceleration, start by measuring the time it takes to travel between the start and end of the journey. Calculate the velocity using the formula: velocity = distance/time. Then ...

There are various methods to measure acceleration due to gravity. At Higher level all rely on one of the equations of motion. The measurements required will depend on the equation used.