試題詳解

33. A system comprises three particles with masses of 2.0 kg, 3.0 kg, and 5.0 kg, respectively. A force F = 3.0i + 4.0j (N) acts on the 2,0-kg particle, where i and/ are unit vectors that point along x and y coordinate axes, respectively. What is the acceleration of the center of mass a_c caused by the force?
(A) a_c = 0.30i+ 0.40j (m/s²)
(B) a_c = 0.60i + 0.80j (m/s²)
(C) a_c = 3.0i +1.0j  (m/s²)
(D) a_c = 3.0i + 4.0j (m/s²)
(E) a_c = 15i + 20j (m/s²)