Chapter 14, Problem 36A

Why does most of the work done in launching a rocket take place when the rocket is still close to Earth’s surface?

To determine

To explain: The reason for most of the work to take place when the rocket is still close to Earth’s surface.

Explanation of Solution

Introduction: To escape from the gravitational pull, excessive force is required i.e. escape velocity.

When a rocket launches from the Earth’s surface than the first stage fully loaded with fuel is still intact which is heavily massive. At that distance acceleration due to gravity is also higher. Thus, more work is done by the rocket to leave the Earth’s gravity.

Conclusion: Thus, to escape from the Earth’s gravity, most of the work is done by the rocket in the first stage to balance and then exceeds the gravitational pull of Earth. Hence, the rocket can escape from gravity.