chung 發問於 科學及數學物理學 · 4 年前

# Gravitation (satellite)?

A satellite is to be launched to orbit round the Earth. In which of the following directions of launching would the energy required be the least?

(Note: The Earth rotates from West to East.) Ans: A

A: due east from a point on the equator

B: due west from a point on the equator

C: due north or south from a point on the equator

D: from the North pole or the South pole

-Is the gravitational potential energy the same at any point on the surface of the Earth? (Because they needed the same amount of work to move from infinity to their position)

-As the orbit can vary and involve different energy after launching, how to decide the least launching energy?

-Although A,B,C has the highest total energy (their KE from circular motion is highest by v=wr), I don't think whoever contains the highest energy at this moment represents a lower launching energy. Work done after launching is needed and it depends on the orbit.(Direction, speed, radius etc.)

• 天同
Lv 7
4 年前
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