標題: [Phy] Force and motion graph一問 [打印本頁] 作者: dsefighter2020 時間: 2018-8-4 02:17 PM 標題: Force and motion graph一問
hi, i want to ask why the answer is E?
謝謝 作者: JasonFung0310 時間: 2018-8-4 05:58 PM
首先,佢係release from rest,咁 t =0嗰陣 v = 0 。
第二,因為佢free fall 緊,net force得weight,所以 a 係constant,所以slope of v-t graph都係constant。
第3,佢bounces several times,有change in direction,所以一定有變正負。
所以E係answer。 作者: nex 時間: 2018-8-11 12:31 PM