In this passage a brief idea is given of the motion of the rolling bodies on an inclined plane. We will consider three cases: objects are released on an incline plane
Case-A: which is smooth.
Case-B: where friction is insufficient to provide pure rolling.
Case-C: where friction is sufficient to provide pure rolling. Force diagram for three cases are as follows: (where symbols have their usual meanings)

Three solid uniform spheres are released on an inclined plane as shown in the figure. The distance between the spheres remains constant during motion in:

Options

A. all three masses
B. case `A` and `B`
C. only case `C`
D. depends on the mass of the spheres

Answer

A

Explanation

Since acceleration is same for all the three spheres, they cover equal distances in equal intervals of time in all the case `a. b` and `c` hence `a`.