Two discs A and B touch each other as shown. A rope tightly wound on disc A is pulled downward with acceleration 2 m/s². Find the friction force (in N) between A and B if there is no slipping.

Question

G1 Physics · Accepted Answer

Write translation ΣF=Ma and rotation Στ about CM=I about CMα, together with the no-slip relation v of CM=ωR and a of CM=αR whenever pure rolling applies. Solving the equations for the shown geometry gives 2.