Difficulty: Easy
Correct Answer: The gravitational attraction of the Earth
Explanation:
What is being asked?
What does escape velocity allow a spacecraft to overcome when launched from Earth?
Given data
Concept/Approach
Escape velocity is the minimum speed needed to escape the gravitational potential of the body from which launch occurs, neglecting atmospheric drag and additional thrust.
Step-by-step reasoning
1) For launch from Earth, the relevant gravitational well is Earth's.2) Achieving escape velocity ensures the object will not fall back under Earth's gravity even without further propulsion.
Common pitfalls
Confusing Earth's gravity with the Moon's gravity or attributing it to air resistance.
Final Answer
The gravitational attraction of the Earth
Discussion & Comments