Which of the following are correct?

Options

A. An astronaut going from the earth to the Moon will experience weightlessness once.
B. When a thin uniform spherical shell gradually shrinks maintaining its shape, the gravitational potential at its centre decreases.
C. In the case of a spherical shell, the plot of `V` versus `r` is continuous.
D. In the case of a spherical shell, the plot of gravitational field intensity `I` versus `r` is continuous

Answer

A, B, C

Explanation

a. For a proper explanation , the earth Moon system will be regared as an isolated system. At a particular point in space, the gravitational force of attraction of the earth on astronaut will be balanced by the gravitational force of attraction of the Moon.
b. `V=-GM//r` . As `R` decreases, `GM//R` increases or `-GMM//R` decreases.
c. In case of the sphereical shell, plot of `I` versus `r` is dicontinous.