A solid cylinder C and a hollow pipe P of same diameter are in contact when they are released from rest as shown in the figure on a long incline plane. Cylinder C and pipe P roll without slipping. Determine the clear gap (in m) between them after 6 seconds.

Question

G1 Physics · Accepted Answer

For rolling down an incline, a=g sinθ/[1+I/(mR²)]. Thus for a solid cylinder a꜀=(2/3)g sinθ, while for a thin hollow pipe aₚ=(1/2)g sinθ. Relative acceleration is Δa=(1/6)g sinθ. With the angle shown and t=6 s, separation =½Δa t² =15 m.