試題詳解

33. As shown in figures (a) and (b), a constant force F is applied to the two contact blocks in both cases. In figure (a), block A pushes against block B with a 20 N force directed horizontally to the right. In figure (b), block A pushes against block B with a 10 N force directed horizontally to the left. The total mass of two blocks is 12 kg. Which of the following statement is correct? (Gravitational acceleration g = 10 m/s² )
  
(A) The magnitude of F is 20 N.
(B) The mass ratio between block A and B is 2.
(C) The acceleration in (a) is 1.5 m/s².
(D) The acceleration in (b) is 2.5 m/s².
(E) The mass of block A is 8 kg.