https://online2.tingclass.net/lesson/shi0529/0009/9697/35.mp3
https://image.tingclass.net/statics/js/2012
Why not? You cry.Well,ask yourself this question:which one is easier to move in the first place? Thegolf ball. So it takes more force to move the bowlingball. And the bowling ball is also the one gravitypulls on more. See the connection? A more massiveobject has more stuff for gravity to act on. Butbecause it is more massive, it is also that muchharder to move! A smaller object is easier to move.But it also has less stuff for gravity to act on! Thecool thing is these two factors exactly balance eachother out. And that’s why any object, from dumptrucks to linguini, falls at exactly the same rate as any other object.
為什么不是重的物體先落地?你喊道。問(wèn)下你自己這個(gè)問(wèn)題:那一個(gè)首先比較容易移動(dòng)?高爾夫球。所以要花更多的力量來(lái)移動(dòng)保齡球,它也是引力作用更多的球。看見(jiàn)聯(lián)系了嗎?質(zhì)量更重的物體引力作用更多但是因?yàn)橘|(zhì)量更大,移動(dòng)也比較難。一個(gè)較小的物體比較容易移動(dòng),但是引力作用也少。最有意思的是這兩種因素互相抵消。那就是任何物體,從自動(dòng)傾卸卡車到寬面條,都會(huì)以和其他物體相同的速度下落的原因。
gravity n.引力 factor n.因素 balance out 抵消 dump truck 自動(dòng)傾卸卡車