5. A space craft is launched from the surface of the Earth with a heliocentric speed of 42 km/s (the speed relative to the Sun). What is its speed when it reaches a distance of 5 AU from the Sun? Note: you have to include the gravitational potential of the Earth as well as the Sun in the calculation.
(A) 12 km/s;
(B) 15km/s;
(C)18 km/s;
(D) 21 km/s;
(E) 24km/s.

答案:登入後查看
統計: A(0), B(2), C(0), D(1), E(0) #2740283

詳解 (共 1 筆)

#7430167
所以這題考機械能守恆
總能量包含三個部分
6a48e799e5488.jpg
地球繞太陽在1AU處的太陽脫離速度
vesc=42km/s
6a48e7e111ab2.jpg
能量守恆
6a48e81233987.jpg
6a48e81bbb83a.jpg
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