Carla and Jenny Are Arguing About Whether or Not It

question 2

Multiple Choice

Carla and Jenny are arguing about whether or not it is possible to escape the gravitational field of the Earth. Carla shows Jenny a system where mass m is r_E (not the Earth's radius) distant from Earth and r_P (not planet P's radius) distant from planet P, the mass being on the line connecting the Earth and planet P. Carla states that the mass m has escaped if F_{P on m} = −F_{E on m}. Jenny disagrees. Which one, if either, is correct, and why?

• A) Carla, because the total gravitational force on m is zero at that point.
• B) Carla, because there is no gravitational force from Earth on m at that point.
• C) Carla, because there is no gravitational force on m from Earth when r > r_E.
• D) Jenny, because there is a gravitational force on m from Earth no matter how great the distance from the Earth.
• E) Jenny, because the gravitational force from the Earth can only be blocked by a body that is larger than the Earth.

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Definitions:

Defined Contribution Plan

A type of retirement plan where the amount contributed to the plan is specified, but the benefit received at retirement depends on the plan's investment performance.

Endowment Fund

A fund established by a foundation, institution, or individual, where the principal amount is kept intact while the investment income is available for use.

Variable Annuity

An insurance product that provides future payments to the holder, with the payouts varying depending on the performance of the investment options chosen.

Defined Contribution

A type of retirement plan in which the amount contributed to the plan is specified, but the future benefit amount is not guaranteed, depending on investment returns.