. In principle, one could think about triggering the photogate on the glider itself, instead of using a flag, i. e. record the time it takes the entire glider to pass the photogate. Would this make the measurement of the speed more or less accurate

That would be kinetic energy

Answer the radiant sun;

Answerthe global climate during the paleogene departed from the hot and humid conditions of the late mesozoic era and began a cooling and drying trend which dispite having been periodically disrupted by warm periods such as the paleocene-eocene thermal maximum, persists today;