英文物理题,关于地心引力的A planet with a mass of 7.99·1021 kg is in a circular orbit around a star with a mass of 4.83·1030 kg.The planet has an orbital radius of 1.99·1010 m.a) What is the linear orbital velocity of the planet?b) What
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英文物理题,关于地心引力的A planet with a mass of 7.99·1021 kg is in a circular orbit around a star with a mass of 4.83·1030 kg.The planet has an orbital radius of 1.99·1010 m.a) What is the linear orbital velocity of the planet?b) What
英文物理题,关于地心引力的
A planet with a mass of 7.99·1021 kg is in a circular orbit around a star with a mass of 4.83·1030 kg.The planet has an orbital radius of 1.99·1010 m.
a) What is the linear orbital velocity of the planet?
b) What is the period of the planet's orbit?
c) What is the total mechanical energy of the planet?
只有第三问怎么也做不出来哭
英文物理题,关于地心引力的A planet with a mass of 7.99·1021 kg is in a circular orbit around a star with a mass of 4.83·1030 kg.The planet has an orbital radius of 1.99·1010 m.a) What is the linear orbital velocity of the planet?b) What
只用做第三问么?
第三问问的是机械能：
机械能为动能+势能.
动能为0.5*(mv^2)
势能为重力势能,重力势能是一个相对的量,假定无穷远处重力势能为0,用定积分（由于重力加速度是个随高度变化的量,所以必须用积分来求,具体见百度百科的重力是能,搜“重力势能的定义式”）可以得到重力势能为-GMm/r.
所以机械能为0.5*(mv^2)+(-GMm/r).
这些量都是题目中的或者前两问求出来的,直接带入就行了.