A body of mass m is projected from the Earth's surface. At the point of launch, the acceleration of free fall is g and the radius of the Earth is R. To escape from the gravitational field of the Earth, the speed of the body must be at least:
Correct answer: A. √(gR)
- A. √(gR)
- B. mgR
- C. √(2gR)
- D. mg/2R
Explanation
a) √(gR):This option suggests that the speed of the body must be at least √(gR) to escape from the gravitational field of the Earth. This is the correct option. The escape speed from the Earth's gravitational field can be calculated using the formula √(2gR), which takes into account the acceleration due to gravity (g) and the radius of the Earth (R). So, this option represents the correct relationship between g and R.
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