請物理高手幫我解物理作業~~拜託~~急急急

1.質量為m1之球 以v1速度向靜止之質量為m2球正向碰撞撞後合為一體則:

(a)其速度為若干?

(b)碰撞前m1及m2球各對質量中心的動量為若干?

(c)碰撞後m1球及m2球各對質量中心的動量為若干?

2.質量為一個單位的質量受F力作用而運動 F與時間T的關係式為F=(3t^2-4t)i (12t-6)j (6t-12t^2)k求?

(a)t=1至t=2期間質點的動量變化量?

(b)若在t=1時 質點的速度為V1=4i-5j 9k則t=2時速度V2=?

3.一靜止物體爆炸後分成三片 其中兩片質量相等 同以30米/秒速率相互垂直飛離 若第三片質量為其他二片質量的倆倍 求在爆炸後其速度為何?

1 Answer

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  • Anonymous
    2 decades ago
    Favorite Answer

    1)a>   (m1*v1) / (m1 + m2)b>   (m1^2 *v1) / (m1 + m2)c>   (m1*m2*v1) / (m1 + m2)2)a>   F = m*a , m = 1 => F = a, v(t) = ∫a(t)dt     t = 1 至 t = 2:     ∆v = |(t^3)i (6t^2 - 6t)j (3t^2-4t^3)k|2-1     ∆v = (8-1) i (12) j (-20+1) k      ∆M = ∆v*m, m = 1 => ∆M = ∆v = 7i 12j -19k3)in x direction:v3 = 30*m / 2m = 15 (m/s)in y direction:v3 = 30*m / 2m = 15 (m/s)=> combine: v3 = √(15^2 + 15^2) = 5√(18) (m/s)

    Source(s): 自己
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