發問時間: 科學其他:科學 · 1 0 年前

視重問題 物理

a 60kg person is in an elevator that is moving upward at 4m/s and slowing down at 2m/s^2 according newton's third law , what is the magnitude of the 'reaction' to the person's weight? on what body is this force exerted?

算出N=468,之後這問題可以解釋一下如何解答

1 個解答

評分
  • Lv 4
    1 0 年前
    最佳解答

    a 60kg person is in an elevator that is moving upward at 4m/s and slowing down at 2m/s^2 according newton's third law , what is the magnitude of the 'reaction' to the person's weight? on what body is this force exerted?

    來個圖~

    圖片參考:http://imgcld.yimg.com/8/n/AC06969796/o/1510111505...

    F (施力)= m(物質量)*a(加速度)

    墨綠色的力是重力

    施力 60*9.8 = 588N

    重力加速度 9.8 m/s^2

    施力向下

    藍色的力是電梯對人的施力

    施力 60*2 = 120

    電梯加速度 2 m/s^2

    施力向上

    所受合力 = 588 - 120 = 468 (因為方向相反所以相減,重力較大所以合力向下)

    視重 : 其受力,相當於多少公斤的東西

    視重= 468 / 9.8 = 47.75

    參考資料: 我~ 你在讀普物~
還有問題?馬上發問,尋求解答。