1)我想問問點解火箭升空後要在太空orbit around the earth之後先至真正咁出到太空? 仲有,佢orbit時,洗唔洗turn on engine呢? 點解? 咁佢正式飛出太空時,又洗唔洗開engine呢? 因為如果佢要change direction,佢係要開engine架嘛。2)仲有,想問下本書話上到太空係weightlessness,但weightlessness只係離心力,同埋火箭falling back to the earth at the same speed as the astronauts,所以support唔到astronauts,點解會搞到d太空人係度轉來轉去既?3)仲有,上到太空,有冇force of gravity act on d物件度呢? 點解? 過左zero gravity,第二個星球既係咪會取代earth既force of gravity,act on d物件度呢?
請大家幫幫忙,解決左我呢d問題,希望中英都有。請詳細咁回答同唔好離題。當然,如果大家有extras,本人無任歡迎。