We rediscover gravity by observing on how ski jumping works, i.e. we will assume to investigate an object which is influenced by the common gravitational law. We will study datasets which describe the trajectory and then find out that they lay all on a parabola. As a experimental setup you can imagine a camera taking shots at a regular interval and the photos are being superimposed.
Up front, we make a contract that we will assume that we put the origin of the coordinate system at the tip of the jump, to make our life a bit easier.
In this exercise we will do the trivial and most basic thing: we will assume everything is as it is supposed to be and there are no hidden things. This means there is basically no fitting needed (just linear algebra), but we will start to setup the fitting framework anyways as preparation for the more realistic scenario considered in Exercise B. So in case of doubt you can always resort to the analytical solution here.
The different groups have different tasks, which are discussed on the respective pages: