An astronaut inside an orbiting spacecraft hangs a book on a spring balance and…
PHYSICS · Single correct · AP · Physics 1: Algebra-based · Force and Translational Dynamics · Force and Translational Dynamics
Problem
An astronaut inside an orbiting spacecraft hangs a 2kg book on a spring balance and observes that the balance reads zero. Which of the following explains this observation most correctly?
(a) There is no gravitational force acting on the book
(b) In orbit, centrifugal force exactly cancels Earth’s gravity, so the book has no weight
(c) The book and the balance are both in free fall, so the spring is not stretched
(d) The mass of the book becomes zero in orbit