作业帮一道英文的物理题,急（关于energy）A simple pendulum of length 2.00 m is made with a mass of 2.00 kg.The mass has a speed of 3.00 m/s when the pendulum is 30.0o above its lowest position.What is the maximum angle away from the lowest posit
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一道英文的物理题,急（关于energy）A simple pendulum of length 2.00 m is made with a mass of 2.00 kg.The mass has a speed of 3.00 m/s when the pendulum is 30.0o above its lowest position.What is the maximum angle away from the lowest posit
一道英文的物理题,急（关于energy）
A simple pendulum of length 2.00 m is made with a mass of 2.00 kg.The mass has a speed of 3.00 m/s when the pendulum is 30.0o above its lowest position.What is the maximum angle away from the lowest position the pendulum will reach?
一道英文的物理题,急（关于energy）A simple pendulum of length 2.00 m is made with a mass of 2.00 kg.The mass has a speed of 3.00 m/s when the pendulum is 30.0o above its lowest position.What is the maximum angle away from the lowest posit
1/2mv^2=mgh
1/2*2*3^2=2*10*h
h=0.45m
(Lcos30-h)/L=cosA
cosA=(2*1.732/2-0.45)/2=0.641
A=carcos0.641=50度
从本题题意来看，要分两种情况讨论。 以钟摆最低点为基准参考点，设该点时钟摆速度为v ①情况1时，小球达到最高点时 1/2mv^2+mg(1-sin60°)L=mgh1 h1=？（不好意思，手头没有计算器。） 角度α1=arccos[（L-h1）/L] ②情况2时，因为不考虑空气阻力，此为理想钟摆模型，故当其摆至右侧对称位置时，与情况1类似（图形为现在情况1沿轴对称到右侧） 所以计算情况与①相同，α2=arccos[（L-h1）/L] 所以综上所述，夹角为----度。 不好意思，数值自己代入下吧。科学计算器上都有相应按键算。 如果觉得我的回答解决了你的问题，请采纳。 你的支持，是我不懈努力的动力！
According to law of conservation of mechanical energy, the follwoing equation can be wretten:
1/2*m*v^2+mgL(1-cos30°)=mgL(1-cosθ) (1)
1/2*m*9+mg*2*(1-cos30°)=mg*2*(1-cosθ)
so the maximum angle θ is
θ=arccos0.416=65.42°
